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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.
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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. --
----------------------------------------------------------------------- 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.
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On Thu, Mar 21, 2019 at 01:47 PM, Siggi wrote:
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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.
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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: |
Re: 475 with no Display and no HV
Hi Ripley:
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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, |
Re: TM504 backplane repair
I concur.
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DaveD Sent from a small flat thingy On Mar 21, 2019, at 13:33, tom jobe <tomjobe@...> wrote: |
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.
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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? |
Re: TM504 backplane repair
Hi Colin
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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,
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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 brightnessPer 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.
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tom jobe... On 3/21/2019 8:22 AM, Colin Herbert via Groups.Io wrote:
Does no-one really have any observations on this? |
Re: TM504 backplane repair
Hi Steve,
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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.
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On Thu, Mar 21, 2019 at 11:19 AM, Siggi wrote:
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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.
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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.
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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. |
Re: TM504 backplane repair
Does no-one really have any observations on this?
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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
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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? |
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.
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On Thu, Mar 21, 2019 at 10:13 AM, Siggi wrote:
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