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Re: TM504 backplane repair

 

I'm fairly certain you have the correct part. There are a few variations that will work. I think the main issue with the part I suggested is you can't put those tabs in that say what kind of module you have. But that wasn't an issue to me.
Sounds like the connector you have is cracked so you will have to replace it. The cracks prevent the tabs from seating on the edge plane correctly so your only choice is to replace it or you will have intermittent contact issues. Getting the PCB out on my TM504A was a PITA and took major disassembly that took a couple hours and a lot of head scratching when I got stuck, so hopefully the TM504 isn't as hard as the TM504A. The A has a fan, larger caps and more parts so maybe that was the issue for me.

If your part is NOS, which I am pretty sure it is based on the fact that EDAC no longer makes them, it is most likely 30 years old or older and will just crack again soon. You can try it but replacing it is so hard I would just use a new 305-056-520-201 so you don't have to do it again. You can get it from Digikey for under $20.


Re: 475 with no Display and no HV

 

Ensure that the silicon sealer does NOT cure with acetic acid.
Use silicone sealer that cures with alcohol.
If it smells like vinegar do not use it on electronics.

Glenn

On 3/21/2019 7:05 PM, SuddenLink wrote:
Good to know. Right now I need to locate a .01uF cap with 5kv or better voltage rating. All that I have in stock only go up to 1kv. I am at the Radio Museum tomorrow. Will see what we have there.

Ripley

The words are mine but this iPad does what it will with them.

On Mar 21, 2019, at 6:13 PM, Reed Dickinson <reed714@...> wrote:

Hi Ripley:

If your scope does not fire up when you have the .01uF cap between the transformer and the NTE539 tripler then the tripler may be blown as your last note implied you tried the tripler without the cap. The cap was present inside the original tripler but you could not see it as the original tripler was potted in Hysol. Try the .01uF cap, the tripler just possibly might still be good.

Reed


On 3/21/2019 4:37 AM, SuddenLink wrote:
Hello Reed,

Ahhh. A .01uF capacitor is the secret. The NTE539 sure doesn¡¯t work with a direct connection to the HV transformer¡¯s secondary. I will give it a try and report back.

Ripley

The words are mine but this iPad does what it will with them.

On Mar 21, 2019, at 12:50 AM, Reed Dickinson <reed714@...> wrote:

Hi Ripley:

You are correct, do not connect to the focus lead, a blob of silicon seal should work. You need to splice the cable going from the tripler to the socket. Slide a piece of shrink wrap tubing over a piece of thick wall plastic tubing over the wires to be spliced, make sure that you have a good lapping solder joint. After the joint cools look closely and be sure there are no sharp pieces of wire showing then generously coat the entire joint with silicon sealer and slide the large piece of tubing over the joint then slide the shrink tubing over the plastic tubing and heat the shrink tubing to seal it. If it is loose use two small tie wraps. Mount the mew tripler where the old tripler was by drilling two holes and install screws. Next connect the transformer output to the IN terminal using a .01uF, 5KV or 10KV cap. The cap must be used to make it work. Connect up and fire it up. Good luck!


Reed


On 3/17/2019 5:28 PM, SuddenLink wrote:
Hi Reed,

I received the NTE539 a few days ago and pulled out the existing HV trippler these evening. It is going to be a tight fit but it looks I can squeeze the new trippler in it¡¯s place. The question is, what do I do with the Focus tab on the NTE539. I am thinking that it gets clipped off and covered with a glob of silicon seal.

I am going to hold off until I hear back from you.

Thank you.

Ripley

Sent from Mail for Windows 10

From: Reed Dickinson
Sent: Tuesday, March 5, 2019 3:11 PM
To: [email protected]
Subject: Re: [TekScopes] 475 with no Display and no HV

Hi:
See answers in red below.

--
-----------------------------------------------------------------------
Glenn Little ARRL Technical Specialist QCWA LM 28417
Amateur Callsign: WB4UIV wb4uiv@... AMSAT LM 2178
QTH: Goose Creek, SC USA (EM92xx) USSVI LM NRA LM SBE ARRL TAPR
"It is not the class of license that the Amateur holds but the class
of the Amateur that holds the license"


Re: 2467B No B Sweep

 

Center pin of Q741 was unsoldered. When I recapped the board I must have desoldered the wrong pin and forgotten to resolder it. Great.

On Thu, Mar 21, 2019 at 01:47 PM, Siggi wrote:


On Thu, Mar 21, 2019 at 12:26 PM <thespin@...> wrote:

Okay one more question before I dig in. How is the trace A brightness
intensified when you first pull the SEC/DIV knob? I assume somehow through
U650. How does it know when to kick the trace brightness up a little over
the region which will later be focused in on? I assume there's some
comparators somewhere.
Per the service manual, page 3a-18:

"To produce the intensified zone on the A Sweep trace for A intensified by
B Sweep displays, an additional current is added to the crt drive signal by
the Z-Axis Amplified during the concurrence of the /SGAZ and /SGBZ (sweep
gate A and B z-axis) signals."

If you think about it for a spell, it makes sense for this to be a function
of the sweep gate signals, because of the complexity that goes into the
timing of the sweeps. If you've ever played with a triggered intensified
B-sweep, you'll know how it jumps around with the B-trigger position.
On these scopes you can view the A and B sweeps simultaneously, with the B
sweep intensified on the A sweep, and then again with a separate trace for
the B sweep. This takes two total sweeps, one for each trace, with
alternate sweep generators coupled to the horizontal amplifier.
I've never tried to verify this, but I expect you'll see both the A and B
gate signals change on every sweep when the B-sweep is engaged, whether the
A or B or both are on display at the time.

Good luck,
Siggi


Re: 475 with no Display and no HV

 

Good to know. Right now I need to locate a .01uF cap with 5kv or better voltage rating. All that I have in stock only go up to 1kv. I am at the Radio Museum tomorrow. Will see what we have there.

Ripley

The words are mine but this iPad does what it will with them.

On Mar 21, 2019, at 6:13 PM, Reed Dickinson <reed714@...> wrote:

Hi Ripley:

If your scope does not fire up when you have the .01uF cap between the transformer and the NTE539 tripler then the tripler may be blown as your last note implied you tried the tripler without the cap. The cap was present inside the original tripler but you could not see it as the original tripler was potted in Hysol. Try the .01uF cap, the tripler just possibly might still be good.

Reed


On 3/21/2019 4:37 AM, SuddenLink wrote:
Hello Reed,

Ahhh. A .01uF capacitor is the secret. The NTE539 sure doesn¡¯t work with a direct connection to the HV transformer¡¯s secondary. I will give it a try and report back.

Ripley

The words are mine but this iPad does what it will with them.

On Mar 21, 2019, at 12:50 AM, Reed Dickinson <reed714@...> wrote:

Hi Ripley:

You are correct, do not connect to the focus lead, a blob of silicon seal should work. You need to splice the cable going from the tripler to the socket. Slide a piece of shrink wrap tubing over a piece of thick wall plastic tubing over the wires to be spliced, make sure that you have a good lapping solder joint. After the joint cools look closely and be sure there are no sharp pieces of wire showing then generously coat the entire joint with silicon sealer and slide the large piece of tubing over the joint then slide the shrink tubing over the plastic tubing and heat the shrink tubing to seal it. If it is loose use two small tie wraps. Mount the mew tripler where the old tripler was by drilling two holes and install screws. Next connect the transformer output to the IN terminal using a .01uF, 5KV or 10KV cap. The cap must be used to make it work. Connect up and fire it up. Good luck!


Reed


On 3/17/2019 5:28 PM, SuddenLink wrote:
Hi Reed,

I received the NTE539 a few days ago and pulled out the existing HV trippler these evening. It is going to be a tight fit but it looks I can squeeze the new trippler in it¡¯s place. The question is, what do I do with the Focus tab on the NTE539. I am thinking that it gets clipped off and covered with a glob of silicon seal.

I am going to hold off until I hear back from you.

Thank you.

Ripley

Sent from Mail for Windows 10

From: Reed Dickinson
Sent: Tuesday, March 5, 2019 3:11 PM
To: [email protected]
Subject: Re: [TekScopes] 475 with no Display and no HV

Hi:
See answers in red below.



Re: 475 with no Display and no HV

 

Hi Ripley:

If your scope does not fire up when you have the .01uF cap between the transformer and the NTE539 tripler then the tripler may be blown as your last note implied you tried the tripler without the cap.? The cap was present inside the original tripler but you could not see it as the original tripler was potted in Hysol.? Try the .01uF cap, the tripler just possibly might still be good.

Reed

On 3/21/2019 4:37 AM, SuddenLink wrote:
Hello Reed,

Ahhh. A .01uF capacitor is the secret. The NTE539 sure doesn¡¯t work with a direct connection to the HV transformer¡¯s secondary. I will give it a try and report back.

Ripley

The words are mine but this iPad does what it will with them.

On Mar 21, 2019, at 12:50 AM, Reed Dickinson <reed714@...> wrote:

Hi Ripley:

You are correct, do not connect to the focus lead, a blob of silicon seal should work. You need to splice the cable going from the tripler to the socket. Slide a piece of shrink wrap tubing over a piece of thick wall plastic tubing over the wires to be spliced, make sure that you have a good lapping solder joint. After the joint cools look closely and be sure there are no sharp pieces of wire showing then generously coat the entire joint with silicon sealer and slide the large piece of tubing over the joint then slide the shrink tubing over the plastic tubing and heat the shrink tubing to seal it. If it is loose use two small tie wraps. Mount the mew tripler where the old tripler was by drilling two holes and install screws. Next connect the transformer output to the IN terminal using a .01uF, 5KV or 10KV cap. The cap must be used to make it work. Connect up and fire it up. Good luck!


Reed


On 3/17/2019 5:28 PM, SuddenLink wrote:
Hi Reed,

I received the NTE539 a few days ago and pulled out the existing HV trippler these evening. It is going to be a tight fit but it looks I can squeeze the new trippler in it¡¯s place. The question is, what do I do with the Focus tab on the NTE539. I am thinking that it gets clipped off and covered with a glob of silicon seal.

I am going to hold off until I hear back from you.

Thank you.

Ripley

Sent from Mail for Windows 10

From: Reed Dickinson
Sent: Tuesday, March 5, 2019 3:11 PM
To: [email protected]
Subject: Re: [TekScopes] 475 with no Display and no HV

Hi:
See answers in red below.


Re: TM504 backplane repair

 

I concur.

DaveD

Sent from a small flat thingy

On Mar 21, 2019, at 13:33, tom jobe <tomjobe@...> wrote:

My suggestion would be to post a few photos of the problem connector and contact.
tom jobe...




On 3/21/2019 8:22 AM, Colin Herbert via Groups.Io wrote:
Does no-one really have any observations on this?
Colin.

-----Original Message-----
From: [email protected] [mailto:[email protected]] On Behalf Of Colin Herbert via Groups.Io
Sent: 17 March 2019 13:43
To: [email protected]
Subject: [TekScopes] TM504 backplane repair

I have a TM504 where contact B22 on the high-power compartment connector has got mangled. It can be seen that it is sitting badly and maybe shorting to A22. I know that this connector isn't used very frequently, but I was hoping to use my PS503A in that compartment to take advantage of the 1A output. I have obtained a brand-new connector (#131-1078-00) and was hoping to be able to use it to effect a repair. I think I have a number of options:

a) Unsolder the entire faulty connector and replace it with the new one - this looks like a formidable task, since there are a total of 56 pins to unsolder and re-solder and access isn't straightforward but it would be the most ideal option, I think. Unfortunately I don't have a de-soldering tool, only a solder-sucker and some poor de-soldering braid (I suppose I could buy a de-soldering tool).

b) Somehow remove the faulty contact and replace it with a good one from the new connector. This would be fine, but it doesn't look easy because of the way the contacts are secured in the new connector, they are not easy to remove as they are retained by way of a punched indentation which has resulted in a raised "dot" on the other side. I have tried crushing this down, but it isn't easy. If the mangled contact in the existing connector is retained in the same manner, I can't see how removal can be managed.

c) Just remove the mangled contact by "brute force and ignorance" and forget about its function for the PS503A (it is -V output) . This wouldn't be ideal but would probably be functional, even though it would irritate me as being imperfect.

d) disconnect the electrical connection to the faulty contact on the TM504. I don't like this idea at all.

e) disconnect the electrical contact on the PS503A. I like this option even less than (d).

Does anyone have any experience of doing such a repair or any other/better ideas?

TIA, Colin.








Re: TM504 backplane repair

 

I have taken a photo, but I have never posted photos to the Forum, so I'm not too sure what to do next. The offending connector does seem to be brittle and has broken at the top.

The replacement connector that I have is an EDAC 303-056-520-301, which I bought new and it came in a damaged Tek packaging with the label 131-1078-00. It certainly looks correct.

From looking at the guts of the TM504 with both top-cover and bottom-cover removed, the bottom seven or eight pins are difficult to access.

Colin.

-----Original Message-----
From: [email protected] [mailto:[email protected]] On Behalf Of tom jobe
Sent: 21 March 2019 17:34
To: [email protected]
Subject: Re: [TekScopes] TM504 backplane repair

My suggestion would be to post a few photos of the problem connector and
contact.
tom jobe...




On 3/21/2019 8:22 AM, Colin Herbert via Groups.Io wrote:
Does no-one really have any observations on this?
Colin.

-----Original Message-----
From: [email protected] [mailto:[email protected]] On Behalf Of Colin Herbert via Groups.Io
Sent: 17 March 2019 13:43
To: [email protected]
Subject: [TekScopes] TM504 backplane repair

I have a TM504 where contact B22 on the high-power compartment connector has got mangled. It can be seen that it is sitting badly and maybe shorting to A22. I know that this connector isn't used very frequently, but I was hoping to use my PS503A in that compartment to take advantage of the 1A output. I have obtained a brand-new connector (#131-1078-00) and was hoping to be able to use it to effect a repair. I think I have a number of options:

a) Unsolder the entire faulty connector and replace it with the new one - this looks like a formidable task, since there are a total of 56 pins to unsolder and re-solder and access isn't straightforward but it would be the most ideal option, I think. Unfortunately I don't have a de-soldering tool, only a solder-sucker and some poor de-soldering braid (I suppose I could buy a de-soldering tool).

b) Somehow remove the faulty contact and replace it with a good one from the new connector. This would be fine, but it doesn't look easy because of the way the contacts are secured in the new connector, they are not easy to remove as they are retained by way of a punched indentation which has resulted in a raised "dot" on the other side. I have tried crushing this down, but it isn't easy. If the mangled contact in the existing connector is retained in the same manner, I can't see how removal can be managed.

c) Just remove the mangled contact by "brute force and ignorance" and forget about its function for the PS503A (it is -V output) . This wouldn't be ideal but would probably be functional, even though it would irritate me as being imperfect.

d) disconnect the electrical connection to the faulty contact on the TM504. I don't like this idea at all.

e) disconnect the electrical contact on the PS503A. I like this option even less than (d).

Does anyone have any experience of doing such a repair or any other/better ideas?

TIA, Colin.







Re: TM504 backplane repair

 

Hi Colin
I live in the UK and frequently exchange damaged individual contacts. ?I have no direct knowledge of the TM504, but, the best way to resolve such a problem is very dependent on the exact connectors used and just how good the access is.
If you take a couple of photographs of the damaged connector and email to me at G6HIG at Yahoo dot com I may be able to advise you
Regards
George G6HIG

On Thursday, March 21, 2019 5:53 PM, Hawker <rick@...> wrote:


I just went through this on my TM504A where the high current pin was bad so the module worked but it didn't sense high current. There were multiple problems, a bad contact and a cracked frame, that I didn't notice until I was in there and had it apart.

First off TM500x connectors go bad, they get brittle from age and heat, crack and go bad. So if it isn't bad now it may eventually. For this reason DO NOT USE A NOS replacement part because the plastic is old and it is likely to crack again. And don't screw around with just replacing the bad contact.
The? EDAC? 305-056-520-201 is not a perfect replacement, the exact part is no longer made. But this part is still available and will work. Us it.

To get the old part out careful work with a Solder Pullet should do it. I didn't have good luck with solder wick.? Go slow and careful and make sure it is fully heated before you hit extract. If you can't get it easily you can cut the connector or pull individual contacts from the other side.

While you are in there put some Deoxit on the large Power BJTs where they slide into the connector and make sure all the BJT screws are tight (but not too tight or you damage the insulator). Also a good time to check the caps and make sure they are all still good.


Re: TM504 backplane repair

 

I just went through this on my TM504A where the high current pin was bad so the module worked but it didn't sense high current. There were multiple problems, a bad contact and a cracked frame, that I didn't notice until I was in there and had it apart.

First off TM500x connectors go bad, they get brittle from age and heat, crack and go bad. So if it isn't bad now it may eventually. For this reason DO NOT USE A NOS replacement part because the plastic is old and it is likely to crack again. And don't screw around with just replacing the bad contact.
The EDAC 305-056-520-201 is not a perfect replacement, the exact part is no longer made. But this part is still available and will work. Us it.

To get the old part out careful work with a Solder Pullet should do it. I didn't have good luck with solder wick. Go slow and careful and make sure it is fully heated before you hit extract. If you can't get it easily you can cut the connector or pull individual contacts from the other side.

While you are in there put some Deoxit on the large Power BJTs where they slide into the connector and make sure all the BJT screws are tight (but not too tight or you damage the insulator). Also a good time to check the caps and make sure they are all still good.


Re: TM504 backplane repair

 

Colin,

OK, well this is way to heavy to ship there. Even USP would be close to $100 and they are not on my "happy" list for international shipping, sorry

steve

-----Original Message-----
From: [email protected] <[email protected]> On Behalf Of Colin Herbert via Groups.Io
Sent: Thursday, March 21, 2019 10:17 AM
To: [email protected]
Subject: Re: [TekScopes] TM504 backplane repair

Hi Steve,
Please bear in mind I live in London, UK.
Colin.

-----Original Message-----
From: [email protected] [mailto:[email protected]] On Behalf Of Stephen Hanselman
Sent: 21 March 2019 16:22
To: [email protected]
Subject: Re: [TekScopes] TM504 backplane repair

I personally use one of the SOLD-A-PULLIT but I do have one maybe two more or less complete Pace re-work stations. These have, again assuming I have all the parts, resistive soldering, solder sucker, low speed Dremel, solder tip temp gauge, plus a couple of switch controlled outlets. If there is any interest I'll check this weekend. They are free to a good home for the cost of boxing and shipping.

steve

-----Original Message-----
From: [email protected] <[email protected]> On Behalf Of J Mcvein via Groups.Io
Sent: Thursday, March 21, 2019 9:10 AM
To: [email protected]
Subject: Re: [TekScopes] TM504 backplane repair

OK - I'll bite - With no good desoldering tools around, I have useda vise-grip to crush the plastic on a edge connector (carefully),into small enough sections to be able to remove the pins one at a time.Use solder wick to clean up, and s drill bit for the stubborn holes.
Tek seemed to use large thru-hole sizes, so using a proper vacuumstation is not out of the question. Ask around to borrow/rent time on one.
JimMc

On Thursday, March 21, 2019, 8:22:59 AM PDT, Colin Herbert via Groups.Io <colingherbert@...> wrote:

Does no-one really have any observations on this?
Colin.

-----Original Message-----
From: [email protected] [mailto:[email protected]] On Behalf Of Colin Herbert via Groups.Io
Sent: 17 March 2019 13:43
To: [email protected]
Subject: [TekScopes] TM504 backplane repair

I have a TM504 where contact B22 on the high-power compartment connector has got mangled. It can be seen that it is sitting badly and maybe shorting to A22. I know that this connector isn't used very frequently, but I was hoping to use my PS503A in that compartment to take advantage of the 1A output. I have obtained a brand-new connector (#131-1078-00) and was hoping to be able to use it to effect a repair. I think I have a number of options:

a) Unsolder the entire faulty connector and replace it with the new one - this looks like a formidable task, since there are a total of 56 pins to unsolder and re-solder and access isn't straightforward but it would be the most ideal option, I think. Unfortunately I don't have a de-soldering tool, only a solder-sucker and some poor de-soldering braid (I suppose I could buy a de-soldering tool).

b) Somehow remove the faulty contact and replace it with a good one from the new connector. This would be fine, but it doesn't look easy because of the way the contacts are secured in the new connector, they are not easy to remove as they are retained by way of a punched indentation which has resulted in a raised "dot" on the other side. I have tried crushing this down, but it isn't easy. If the mangled contact in the existing connector is retained in the same manner, I can't see how removal can be managed.

c) Just remove the mangled contact by "brute force and ignorance" and forget about its function for the PS503A (it is -V output) . This wouldn't be ideal but would probably be functional, even though it would irritate me as being imperfect.

d) disconnect the electrical connection to the faulty contact on the TM504. I don't like this idea at all.

e) disconnect the electrical contact on the PS503A. I like this option even less than (d).

Does anyone have any experience of doing such a repair or any other/better ideas?

TIA, Colin.


Re: 2467B No B Sweep

 

On Thu, Mar 21, 2019 at 12:26 PM <thespin@...> wrote:

Okay one more question before I dig in. How is the trace A brightness
intensified when you first pull the SEC/DIV knob? I assume somehow through
U650. How does it know when to kick the trace brightness up a little over
the region which will later be focused in on? I assume there's some
comparators somewhere.
Per the service manual, page 3a-18:

"To produce the intensified zone on the A Sweep trace for A intensified by
B Sweep displays, an additional current is added to the crt drive signal by
the Z-Axis Amplified during the concurrence of the /SGAZ and /SGBZ (sweep
gate A and B z-axis) signals."

If you think about it for a spell, it makes sense for this to be a function
of the sweep gate signals, because of the complexity that goes into the
timing of the sweeps. If you've ever played with a triggered intensified
B-sweep, you'll know how it jumps around with the B-trigger position.
On these scopes you can view the A and B sweeps simultaneously, with the B
sweep intensified on the A sweep, and then again with a separate trace for
the B sweep. This takes two total sweeps, one for each trace, with
alternate sweep generators coupled to the horizontal amplifier.
I've never tried to verify this, but I expect you'll see both the A and B
gate signals change on every sweep when the B-sweep is engaged, whether the
A or B or both are on display at the time.

Good luck,
Siggi


Re: TM504 backplane repair

tom jobe
 

My suggestion would be to post a few photos of the problem connector and contact.
tom jobe...

On 3/21/2019 8:22 AM, Colin Herbert via Groups.Io wrote:
Does no-one really have any observations on this?
Colin.

-----Original Message-----
From: [email protected] [mailto:[email protected]] On Behalf Of Colin Herbert via Groups.Io
Sent: 17 March 2019 13:43
To: [email protected]
Subject: [TekScopes] TM504 backplane repair

I have a TM504 where contact B22 on the high-power compartment connector has got mangled. It can be seen that it is sitting badly and maybe shorting to A22. I know that this connector isn't used very frequently, but I was hoping to use my PS503A in that compartment to take advantage of the 1A output. I have obtained a brand-new connector (#131-1078-00) and was hoping to be able to use it to effect a repair. I think I have a number of options:

a) Unsolder the entire faulty connector and replace it with the new one - this looks like a formidable task, since there are a total of 56 pins to unsolder and re-solder and access isn't straightforward but it would be the most ideal option, I think. Unfortunately I don't have a de-soldering tool, only a solder-sucker and some poor de-soldering braid (I suppose I could buy a de-soldering tool).

b) Somehow remove the faulty contact and replace it with a good one from the new connector. This would be fine, but it doesn't look easy because of the way the contacts are secured in the new connector, they are not easy to remove as they are retained by way of a punched indentation which has resulted in a raised "dot" on the other side. I have tried crushing this down, but it isn't easy. If the mangled contact in the existing connector is retained in the same manner, I can't see how removal can be managed.

c) Just remove the mangled contact by "brute force and ignorance" and forget about its function for the PS503A (it is -V output) . This wouldn't be ideal but would probably be functional, even though it would irritate me as being imperfect.

d) disconnect the electrical connection to the faulty contact on the TM504. I don't like this idea at all.

e) disconnect the electrical contact on the PS503A. I like this option even less than (d).

Does anyone have any experience of doing such a repair or any other/better ideas?

TIA, Colin.






Re: TM504 backplane repair

 

Hi Steve,
Please bear in mind I live in London, UK.
Colin.

-----Original Message-----
From: [email protected] [mailto:[email protected]] On Behalf Of Stephen Hanselman
Sent: 21 March 2019 16:22
To: [email protected]
Subject: Re: [TekScopes] TM504 backplane repair

I personally use one of the SOLD-A-PULLIT but I do have one maybe two more or less complete Pace re-work stations. These have, again assuming I have all the parts, resistive soldering, solder sucker, low speed Dremel, solder tip temp gauge, plus a couple of switch controlled outlets. If there is any interest I'll check this weekend. They are free to a good home for the cost of boxing and shipping.

steve

-----Original Message-----
From: [email protected] <[email protected]> On Behalf Of J Mcvein via Groups.Io
Sent: Thursday, March 21, 2019 9:10 AM
To: [email protected]
Subject: Re: [TekScopes] TM504 backplane repair

OK - I'll bite - With no good desoldering tools around, I have useda vise-grip to crush the plastic on a edge connector (carefully),into small enough sections to be able to remove the pins one at a time.Use solder wick to clean up, and s drill bit for the stubborn holes.
Tek seemed to use large thru-hole sizes, so using a proper vacuumstation is not out of the question. Ask around to borrow/rent time on one.
JimMc

On Thursday, March 21, 2019, 8:22:59 AM PDT, Colin Herbert via Groups.Io <colingherbert@...> wrote:

Does no-one really have any observations on this?
Colin.

-----Original Message-----
From: [email protected] [mailto:[email protected]] On Behalf Of Colin Herbert via Groups.Io
Sent: 17 March 2019 13:43
To: [email protected]
Subject: [TekScopes] TM504 backplane repair

I have a TM504 where contact B22 on the high-power compartment connector has got mangled. It can be seen that it is sitting badly and maybe shorting to A22. I know that this connector isn't used very frequently, but I was hoping to use my PS503A in that compartment to take advantage of the 1A output. I have obtained a brand-new connector (#131-1078-00) and was hoping to be able to use it to effect a repair. I think I have a number of options:

a) Unsolder the entire faulty connector and replace it with the new one - this looks like a formidable task, since there are a total of 56 pins to unsolder and re-solder and access isn't straightforward but it would be the most ideal option, I think. Unfortunately I don't have a de-soldering tool, only a solder-sucker and some poor de-soldering braid (I suppose I could buy a de-soldering tool).

b) Somehow remove the faulty contact and replace it with a good one from the new connector. This would be fine, but it doesn't look easy because of the way the contacts are secured in the new connector, they are not easy to remove as they are retained by way of a punched indentation which has resulted in a raised "dot" on the other side. I have tried crushing this down, but it isn't easy. If the mangled contact in the existing connector is retained in the same manner, I can't see how removal can be managed.

c) Just remove the mangled contact by "brute force and ignorance" and forget about its function for the PS503A (it is -V output) . This wouldn't be ideal but would probably be functional, even though it would irritate me as being imperfect.

d) disconnect the electrical connection to the faulty contact on the TM504. I don't like this idea at all.

e) disconnect the electrical contact on the PS503A. I like this option even less than (d).

Does anyone have any experience of doing such a repair or any other/better ideas?

TIA, Colin.


Re: 2467B No B Sweep

 

Okay one more question before I dig in. How is the trace A brightness intensified when you first pull the SEC/DIV knob? I assume somehow through U650. How does it know when to kick the trace brightness up a little over the region which will later be focused in on? I assume there's some comparators somewhere.

On Thu, Mar 21, 2019 at 11:19 AM, Siggi wrote:


The 2465B has a separate CURSOR 0 line, but DLY REF 1 is shared. I think
this was done to allow cursors under delay sweeps. I'd guess DLY REF 0
controls the B-sweep timing, so I'd take a gander in your shoes.

On Thu, Mar 21, 2019 at 11:07 AM <thespin@...> wrote:

DLY REF 0/1 also control the position of the vertical cursors, right?
These function just fine, so I don't think it's these control lines.

On Thu, Mar 21, 2019 at 10:13 AM, Siggi wrote:


On Thu, Mar 21, 2019 at 9:48 AM Chuck Harris <cfharris@...> wrote:

4051 MUX's fail regularly, as do the opamps in the sample and hold
cells... and be suspicious of any CA3046's, or 3346's. on
occasion one of the sample and hold storage capacitors will get
leaky.
I also remember a case where a decoupling capacitor on the mainboard side
of one of the A5 control lines went leaky and pulled the control signal
down.



Re: TM504 backplane repair

 

I personally use one of the SOLD-A-PULLIT but I do have one maybe two more or less complete Pace re-work stations. These have, again assuming I have all the parts, resistive soldering, solder sucker, low speed Dremel, solder tip temp gauge, plus a couple of switch controlled outlets. If there is any interest I'll check this weekend. They are free to a good home for the cost of boxing and shipping.

steve

-----Original Message-----
From: [email protected] <[email protected]> On Behalf Of J Mcvein via Groups.Io
Sent: Thursday, March 21, 2019 9:10 AM
To: [email protected]
Subject: Re: [TekScopes] TM504 backplane repair

OK - I'll bite - With no good desoldering tools around, I have useda vise-grip to crush the plastic on a edge connector (carefully),into small enough sections to be able to remove the pins one at a time.Use solder wick to clean up, and s drill bit for the stubborn holes.
Tek seemed to use large thru-hole sizes, so using a proper vacuumstation is not out of the question. Ask around to borrow/rent time on one.
JimMc

On Thursday, March 21, 2019, 8:22:59 AM PDT, Colin Herbert via Groups.Io <colingherbert@...> wrote:

Does no-one really have any observations on this?
Colin.

-----Original Message-----
From: [email protected] [mailto:[email protected]] On Behalf Of Colin Herbert via Groups.Io
Sent: 17 March 2019 13:43
To: [email protected]
Subject: [TekScopes] TM504 backplane repair

I have a TM504 where contact B22 on the high-power compartment connector has got mangled. It can be seen that it is sitting badly and maybe shorting to A22. I know that this connector isn't used very frequently, but I was hoping to use my PS503A in that compartment to take advantage of the 1A output. I have obtained a brand-new connector (#131-1078-00) and was hoping to be able to use it to effect a repair. I think I have a number of options:

a) Unsolder the entire faulty connector and replace it with the new one - this looks like a formidable task, since there are a total of 56 pins to unsolder and re-solder and access isn't straightforward but it would be the most ideal option, I think. Unfortunately I don't have a de-soldering tool, only a solder-sucker and some poor de-soldering braid (I suppose I could buy a de-soldering tool).

b) Somehow remove the faulty contact and replace it with a good one from the new connector. This would be fine, but it doesn't look easy because of the way the contacts are secured in the new connector, they are not easy to remove as they are retained by way of a punched indentation which has resulted in a raised "dot" on the other side. I have tried crushing this down, but it isn't easy. If the mangled contact in the existing connector is retained in the same manner, I can't see how removal can be managed.

c) Just remove the mangled contact by "brute force and ignorance" and forget about its function for the PS503A (it is -V output) . This wouldn't be ideal but would probably be functional, even though it would irritate me as being imperfect.

d) disconnect the electrical connection to the faulty contact on the TM504. I don't like this idea at all.

e) disconnect the electrical contact on the PS503A. I like this option even less than (d).

Does anyone have any experience of doing such a repair or any other/better ideas?

TIA, Colin.


Re: TM504 backplane repair

 

OK - I'll bite - With no good desoldering tools around, I have useda vise-grip to crush the plastic on a edge connector (carefully),into small enough sections to be able to remove the pins one at a time.Use solder wick to clean up, and s drill bit for the stubborn holes.
Tek seemed to use large thru-hole sizes, so using a proper vacuumstation is not out of the question.? Ask around to borrow/rent time on one.
JimMc

On Thursday, March 21, 2019, 8:22:59 AM PDT, Colin Herbert via Groups.Io <colingherbert@...> wrote:

Does no-one really have any observations on this?
Colin.

-----Original Message-----
From: [email protected] [mailto:[email protected]] On Behalf Of Colin Herbert via Groups.Io
Sent: 17 March 2019 13:43
To: [email protected]
Subject: [TekScopes] TM504 backplane repair

I have a TM504 where contact B22 on the high-power compartment connector has got mangled. It can be seen that it is sitting badly and maybe shorting to A22. I know that this connector isn't used very frequently, but I was hoping to use my PS503A in that compartment to take advantage of the 1A output. I have obtained a brand-new connector (#131-1078-00) and was hoping to be able to use it to effect a repair. I think I have a number of options:

a) Unsolder the entire faulty connector and replace it with the new one - this looks like a formidable task, since there are a total of 56 pins to unsolder and re-solder and access isn't straightforward but it would be the most ideal option, I think. Unfortunately I don't have a de-soldering tool, only a solder-sucker and some poor de-soldering braid (I suppose I could buy a de-soldering tool).

b) Somehow remove the faulty contact and replace it with a good one from the new connector. This would be fine, but it doesn't look easy because of the way the contacts are secured in the new connector, they are not easy to remove as they are retained by way of a punched indentation which has resulted in a raised "dot" on the other side. I have tried crushing this down, but it isn't easy. If the mangled contact in the existing connector is retained in the same manner, I can't see how removal can be managed.

c) Just remove the mangled contact by "brute force and ignorance" and forget about its function for the PS503A (it is -V output) . This wouldn't be ideal but would probably be functional, even though it would irritate me as being imperfect.

d) disconnect the electrical connection to the faulty contact on the TM504. I don't like this idea at all.

e) disconnect the electrical contact on the PS503A. I like this option even less than (d).

Does anyone have any experience of doing such a repair or any other/better ideas?

TIA, Colin.


Re: TM504 backplane repair

 

On Thu, 21 Mar 2019 15:22:47 -0000, you wrote:

Does no-one really have any observations on this?
I'll weigh in, but I haven't done this, which is why I had no comment.

I'd try removing the bad contact. That's only one contact, and it
you'd have to do this regardless.

Next, I'd look to see how to get a replacement contact out of the
donor. You might end up putting a very thin shim down the outside of
the contact to press the tab in. Even if you don't manage to do this,
you've removed the bad contact.

Best I can suggest.

Harvey



Colin.

-----Original Message-----
From: [email protected] [mailto:[email protected]] On Behalf Of Colin Herbert via Groups.Io
Sent: 17 March 2019 13:43
To: [email protected]
Subject: [TekScopes] TM504 backplane repair

I have a TM504 where contact B22 on the high-power compartment connector has got mangled. It can be seen that it is sitting badly and maybe shorting to A22. I know that this connector isn't used very frequently, but I was hoping to use my PS503A in that compartment to take advantage of the 1A output. I have obtained a brand-new connector (#131-1078-00) and was hoping to be able to use it to effect a repair. I think I have a number of options:

a) Unsolder the entire faulty connector and replace it with the new one - this looks like a formidable task, since there are a total of 56 pins to unsolder and re-solder and access isn't straightforward but it would be the most ideal option, I think. Unfortunately I don't have a de-soldering tool, only a solder-sucker and some poor de-soldering braid (I suppose I could buy a de-soldering tool).

b) Somehow remove the faulty contact and replace it with a good one from the new connector. This would be fine, but it doesn't look easy because of the way the contacts are secured in the new connector, they are not easy to remove as they are retained by way of a punched indentation which has resulted in a raised "dot" on the other side. I have tried crushing this down, but it isn't easy. If the mangled contact in the existing connector is retained in the same manner, I can't see how removal can be managed.

c) Just remove the mangled contact by "brute force and ignorance" and forget about its function for the PS503A (it is -V output) . This wouldn't be ideal but would probably be functional, even though it would irritate me as being imperfect.

d) disconnect the electrical connection to the faulty contact on the TM504. I don't like this idea at all.

e) disconnect the electrical contact on the PS503A. I like this option even less than (d).

Does anyone have any experience of doing such a repair or any other/better ideas?

TIA, Colin.







Re: TM504 backplane repair

 

Does no-one really have any observations on this?
Colin.

-----Original Message-----
From: [email protected] [mailto:[email protected]] On Behalf Of Colin Herbert via Groups.Io
Sent: 17 March 2019 13:43
To: [email protected]
Subject: [TekScopes] TM504 backplane repair

I have a TM504 where contact B22 on the high-power compartment connector has got mangled. It can be seen that it is sitting badly and maybe shorting to A22. I know that this connector isn't used very frequently, but I was hoping to use my PS503A in that compartment to take advantage of the 1A output. I have obtained a brand-new connector (#131-1078-00) and was hoping to be able to use it to effect a repair. I think I have a number of options:

a) Unsolder the entire faulty connector and replace it with the new one - this looks like a formidable task, since there are a total of 56 pins to unsolder and re-solder and access isn't straightforward but it would be the most ideal option, I think. Unfortunately I don't have a de-soldering tool, only a solder-sucker and some poor de-soldering braid (I suppose I could buy a de-soldering tool).

b) Somehow remove the faulty contact and replace it with a good one from the new connector. This would be fine, but it doesn't look easy because of the way the contacts are secured in the new connector, they are not easy to remove as they are retained by way of a punched indentation which has resulted in a raised "dot" on the other side. I have tried crushing this down, but it isn't easy. If the mangled contact in the existing connector is retained in the same manner, I can't see how removal can be managed.

c) Just remove the mangled contact by "brute force and ignorance" and forget about its function for the PS503A (it is -V output) . This wouldn't be ideal but would probably be functional, even though it would irritate me as being imperfect.

d) disconnect the electrical connection to the faulty contact on the TM504. I don't like this idea at all.

e) disconnect the electrical contact on the PS503A. I like this option even less than (d).

Does anyone have any experience of doing such a repair or any other/better ideas?

TIA, Colin.


Re: 2467B No B Sweep

 

The 2465B has a separate CURSOR 0 line, but DLY REF 1 is shared. I think
this was done to allow cursors under delay sweeps. I'd guess DLY REF 0
controls the B-sweep timing, so I'd take a gander in your shoes.

On Thu, Mar 21, 2019 at 11:07 AM <thespin@...> wrote:

DLY REF 0/1 also control the position of the vertical cursors, right?
These function just fine, so I don't think it's these control lines.

On Thu, Mar 21, 2019 at 10:13 AM, Siggi wrote:


On Thu, Mar 21, 2019 at 9:48 AM Chuck Harris <cfharris@...> wrote:

4051 MUX's fail regularly, as do the opamps in the sample and hold
cells... and be suspicious of any CA3046's, or 3346's. on
occasion one of the sample and hold storage capacitors will get
leaky.
I also remember a case where a decoupling capacitor on the mainboard side
of one of the A5 control lines went leaky and pulled the control signal
down.



Re: 2467B No B Sweep

 

DLY REF 0/1 also control the position of the vertical cursors, right? These function just fine, so I don't think it's these control lines.

On Thu, Mar 21, 2019 at 10:13 AM, Siggi wrote:


On Thu, Mar 21, 2019 at 9:48 AM Chuck Harris <cfharris@...> wrote:

4051 MUX's fail regularly, as do the opamps in the sample and hold
cells... and be suspicious of any CA3046's, or 3346's. on
occasion one of the sample and hold storage capacitors will get
leaky.
I also remember a case where a decoupling capacitor on the mainboard side
of one of the A5 control lines went leaky and pulled the control signal
down.