Yep Albert,
Indeed, it was your post I was referring to... I wasn't sure though, if there was still a misunderstanding that the +55V was at fault.
I see now what you mean... and indeed, the shorted decoupling capacitor on the +15V supply doesn't explain (at least, not directly) why the +55V was low until then.
If nothing else was burnt, than I suppose that the circuits that are fed from the +55V (I think of Vertical amplifier, which is the main power hog for the +55V), by being improperly biased (due to the absence of the +15V) were maybe drawing too much current from the +55V, causing it to be lowered??? That's just a big question-mark yet to be answered.
The absence of the +15V and improper biasing of all its "customers", who knows for how long, may have led to other things burning as well, which may explain the now low voltage of the -8V.
Or it may simply be another dreaded tantalum capacitor.
Rgrds,
Fabio
toggle quoted message
Show quoted text
On Mon, Jul 2, 2018 at 11:52 am, Albert Otten wrote:
Hi Fabio,
I have two comments...
1. I got confused by some post of another member, after yours #149308, still
providing suggestions for the low +55V condition... as if it would still be
on
the low side.
This takes me to conclude that it's not very clear to everybody there's
nothing wrong anymore, either with the +55V, or with the +15V.
[snip]
Fabio
That other member must have been me I think. But I wrote this:
I suppose that since 55.66 V is OK the low reading 46.9 V can only be due to
a too heavy load at the +55V rail.
So what I meant is that since there is no problem *now* with +55V, there was
also no problem *earlier*, and the earlier reading 46.9 V can only be
explained by a (then) to heavy load on the +55V rail. I wondered where that
heavy load could come from but didn't find the answer. And apparently nobody
so far (but I guess nobody is searching for that...).
Albert
|
Re: What are these Tek parts for?
wow.. awesome . .thanks for providing that. Yes, would love some photos and do you know where I can go to get those parts? Or, am I really just subject to digging around the aftermarket? On Mon, Jul 2, 2018 at 3:29 PM, Colin Herbert via Groups.Io < colingherbert@...> wrote: I have a 7623A with option #8 (the front cover). The catch hooks on the
scope itself also have a thicker metal stand-off under the hook. If you
can't get the proper items, I can take some measurements and photos to
help. The relevant Tek part numbers are:
105-0390-00 Catch, clamping Nielsen
Hardware Corp. Part No. SC-B-83314
213-0119-00 Screw, tapping, 4-24 x 0.375 inch, pan head, steel.
Central Screw Co.
361-0480-00 Spacer, latch
Tektronix
Good Luck, Colin.
-----Original Message-----
From: [email protected] [mailto:[email protected]] On Behalf Of David
Berlind
Sent: 02 July 2018 16:58
To: [email protected]
Subject: Re: [TekScopes] What are these Tek parts for?
OK. It appears you are correct about the left part. I now realize that my
OS-245 (milspec 7603) is missing the receiving side of the clips to which
the cover attaches. I've added photos to the aforementioned online image
album <>. So, I'd like to find
those clips if someone know where I can get them. Either that, or I'll have
to fabricate them. I bump into these sorts of clips all the time (trying to
think if there something around the house I can harvest them from).
But the other part pictured does not match up to anything I can tell.
On Mon, Jul 2, 2018 at 6:43 AM, Colin Herbert via Groups.Io <
colingherbert@...> wrote:
One of those looks like the front cover for a series-7000 scope (option
#8). It even still has the foam bits for holding probe parts. I've no idea
what the other thing is, but could it be some kind of implosion screen?
Colin.
-----Original Message-----
From: [email protected] [mailto:[email protected]] On Behalf Of David
Berlind
Sent: 02 July 2018 02:14
To: [email protected]
Subject: [TekScopes] What are these Tek parts for?
Two parts... some sort of cover.. but I don't think it's for anything I
own. Smells like an old Tek scope too! If I have no need for this and
someone else does, I'd be happy to stick it in a box if you cover postage.
|
Re: What are these Tek parts for?
I have a 7623A with option #8 (the front cover). The catch hooks on the scope itself also have a thicker metal stand-off under the hook. If you can't get the proper items, I can take some measurements and photos to help. The relevant Tek part numbers are:
105-0390-00 Catch, clamping Nielsen Hardware Corp. Part No. SC-B-83314
213-0119-00 Screw, tapping, 4-24 x 0.375 inch, pan head, steel. Central Screw Co.
361-0480-00 Spacer, latch Tektronix
Good Luck, Colin.
toggle quoted message
Show quoted text
-----Original Message----- From: [email protected] [mailto: [email protected]] On Behalf Of David Berlind Sent: 02 July 2018 16:58 To: [email protected]Subject: Re: [TekScopes] What are these Tek parts for? OK. It appears you are correct about the left part. I now realize that my OS-245 (milspec 7603) is missing the receiving side of the clips to which the cover attaches. I've added photos to the aforementioned online image album <>. So, I'd like to find those clips if someone know where I can get them. Either that, or I'll have to fabricate them. I bump into these sorts of clips all the time (trying to think if there something around the house I can harvest them from). But the other part pictured does not match up to anything I can tell. On Mon, Jul 2, 2018 at 6:43 AM, Colin Herbert via Groups.Io < colingherbert@...> wrote: One of those looks like the front cover for a series-7000 scope (option
#8). It even still has the foam bits for holding probe parts. I've no idea
what the other thing is, but could it be some kind of implosion screen?
Colin.
-----Original Message-----
From: [email protected] [mailto:[email protected]] On Behalf Of David
Berlind
Sent: 02 July 2018 02:14
To: [email protected]
Subject: [TekScopes] What are these Tek parts for?
Two parts... some sort of cover.. but I don't think it's for anything I
own. Smells like an old Tek scope too! If I have no need for this and
someone else does, I'd be happy to stick it in a box if you cover postage.
|
Thanks for the info! About what I expected though. It seems like the letter scopes are much more popular, probably because of their hackability. I still think I got a good deal on this scope (Paid less than $200 shipped), all it appears to really need is a recapping. I have read about the horror stories about damaged passives and traces, so I hope this one isn¡¯t very bad off. It is supposed to be delivered today, so I will be able to get a better idea later today.
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Show quoted text
-----Original Message----- From: [email protected] < [email protected]> On Behalf Of zenith5106 Sent: Saturday, June 30, 2018 3:36 PM To: [email protected]Subject: Re: [TekScopes] TDS5xx upgrades/mods On Sat, Jun 30, 2018 at 12:37 pm, Miles Paulson wrote:
I just purchased a TDS520 non letter scope. I am still waiting for it
to be delivered, and I will need to recap it as it has a few errors.
But, I have been looking without much success for any upgrades or mods
for the non letter scopes. I have been wondering if it is possible to
upgrade the 520 to a 540 without much fuss. Also, I am wondering if
it's possible to add a VGA out like the letter scopes?
Thanks
TDS520 and TDS540 share most of the hardware so it can be done but probably with more fuss than you want. Since the Acq boards are totally different you will need such a board from a TDS540, TDS540A or TDS544A. You must also be able to load TDS540 firmware and then perform a complete Adjustments procedure which takes hours and require calibration instruments like a DC calibrator and a leveled 500 MHz signal generator. Adding a couple of BNC connectors on the rear panel has to done if you want it to be like a TDS540. As far as I remember there is no VGA connector on the CPU/Display board. /H?kan
|
Hi Fabio,
I have two comments...
1. I got confused by some post of another member, after yours #149308, still
providing suggestions for the low +55V condition... as if it would still be on
the low side.
This takes me to conclude that it's not very clear to everybody there's
nothing wrong anymore, either with the +55V, or with the +15V.
[snip]
Fabio
That other member must have been me I think. But I wrote this:
I suppose that since 55.66 V is OK the low reading 46.9 V can only be due to a too heavy load at the +55V rail.
So what I meant is that since there is no problem *now* with +55V, there was also no problem *earlier*, and the earlier reading 46.9 V can only be explained by a (then) to heavy load on the +55V rail. I wondered where that heavy load could come from but didn't find the answer. And apparently nobody so far (but I guess nobody is searching for that...). Albert
|
Re: 7912AD Fails start-up self-test (perhaps)
Hi folks and thanks to all for the input, the video was really reassuring as the LED activity matched what I'm seeing. It also might tie in with the service guide description of what's going on in firmware during the power-up sequence where "one of the first things to happen is the Main and Graticule intensity levels are cleared (two flashes?) then writes the value at the address (one more flash?)"
So reassured the processor was doing something at least I started thinking what else could stop the buttons lighting up?
Then came the light bulb moment (so to speak) there are lamps, not LEDs in them thar switches, you don't suppose....? (embarrassed cough) oh yes, the filaments of the 'TV' and 'Local' lamps both open circuit although the others were fine. Changed them out, reassembled the panel and ALL the lights now worked in the expected sequence! I haven't traced the connections yet but either the processor is reading back that the lamps are good - unlikely that we have aerospace type BIT in this box? - or taking things apart and putting them back got the other button-lights going somehow? Very odd but set that aside (for now, but I know it's going to nag at me in the still dark watches of the night).
So on to step 2. I fired up the 634 video monitor and yup a burning smell and yup another blue tant gone! Do they really hate me that much?? However after fixing that I now see a raster and the readouts from the plugins - 7A29 and 7B90P - which is some progress.? Advancing the Graticule and Main intensities produces screen activity but very much rolling and out of sync in X & Y (although the readout displays are rock solid) so I guess I now need to read different bits of manual but any pointers will be very welcome!
Dare I turn on the 624 X-Y display and look at the digital images? Probably, but I'm checking ohms on the power rails first this time!
I'll keep you posted and thanks again,
Adrian
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On 7/2/2018 12:01 PM, cmjones01 wrote: I've just made a couple of short movies of my 7912AD waking from its slumber. The lights change as you describe and the 'reduce intensity' LED does flash in the pattern you mention.
|
Two more plugins. An early 3S6 and a reasonable S/N 3T6.
The issue with early S/Ns issues with external control.
Pictures have been added to the album
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On Sun, Jul 1, 2018, 8:06 PM Pete Lancashire <xyzzypdx@...> wrote: Here's some photos of the 568 & 3T6 I got from a local Surplus Store.
They're pretty crappy photos the Sun is going down but somebody wanted to
see them.
I wish I still had my mod sheets of all the different S3100 mods and mods
to the 568 3T6/3S6 we did for the S3200 family.
I guess just more things to figure out.
Plug-in wise it's starting to look like getting a clean 3S6 might be an
issue.
On Sun, Jul 1, 2018, 1:51 PM Pete Lancashire <xyzzypdx@...> wrote:
It's going to be a big project I hope to be able to complete at least parts
of it so that whoever may take it on after me will not have a hard time
finishing it ?
Very few people know the history of ATE Tektronix was decades ahead of
everybody else. And also made a bundle of money in the process.
Unfortunately almost everybody involved got no recognition.
On Sun, Jul 1, 2018, 11:09 AM Miguel Work <harrimansat@...> wrote:
Amazing, please photos!!!
-----Mensaje original-----
De: [email protected] [mailto:[email protected]] En nombre de Pete
Lancashire
Enviado el: domingo, 1 de julio de 2018 18:00
Para: [email protected]
Asunto: [TekScopes] s3100 restoration
I acquired a very clean 568 & 3T6 yesterday. Pictures by end of day.
Registered S3100.org
Put offers on 2 x sampling head extenders and were accepted.
Need / looking for
- Plugin paddle boards, or one I can use to get boars made
- Board extenders for the inside boards in the 3T6
- P/N for the interconnect cables and cables
- A-3A heads and accessories.
- R241 & cards, etc.
- S3110 rack. there must be on in the Beaverton/Portland area, Even the
name plate would be nice.
- Test drawer, dut holder etc
- Integration manual (interconnect) not needed but would be nice to
have, does give p/n's for all cables.
Next week will be picking up at least one mouse poop covered R230 and
at
least two R568s for parts.
|
Hello Russ,
Glad to hear that the +15V PS woke up, and by consequence, the +5V and also, somewhat, the -8V (although this one is clearly on the lack).
I have two comments...
1. I got confused by some post of another member, after yours #149308, still providing suggestions for the low +55V condition... as if it would still be on the low side.
This takes me to conclude that it's not very clear to everybody there's nothing wrong anymore, either with the +55V, or with the +15V.
Maybe you can elucidate a little on that to avoid further misunderstanding.
I`m also somewhat puzzled by the description of the capacitor you found guilty at the C1549 position.
There couldn't be a mylar capacitor there... first because a 47uF mylar capacitor would be humongous and wouldn't even fit in that space... second because it would be very unlikely to fail under such low voltage... The least voltage I've ever seen a film capacitor was something like 63V.
Well, me puzzled or not... it seems you grabbed the bulls by the horn. Cheers for that.
2. Regarding the -8V power supply... I'm afraid that, while you were so lucky on the +15V side, to find the shorted culprit in the very first attempt, you may not be so lucky this time... First because it's not a "dead short"... it can be just something drawing too much current (such as another decoupling capacitor), or maybe the -8V power supply is at fault.
Anyway, when you find a wrong power supply rail, there's not much troubleshooting advice than to hunt down the power sucker... it can be anything connected to that particular rail.
Sometimes you're lucky and that supply is distributed through connectors and cables... and in such case, you can rule-out possible culprits by just lifting the pin on the connector, narrowing down the number of places to look for possible culprits.
The -8V power supply looks rather unintuitive, because they chose to make it a "positive supply", and hook the "regulated" positive output to ground, while taking the negative output from the "unregulated" output of the rectifier and bulk capacitor.
But other than that, it is and it works exactly the same as the +15V supply, and the troubleshooting is also the same, just transposing the measurements to the corresponding components.
Kindest Rgrds,
Fabio
P.S. Sorry for your fellow folks there in MEX. Today was our lucky day (I`m Brazilian).
toggle quoted message
Show quoted text
On Fri, Jun 29, 2018 at 10:57 am, musicamex wrote:
One step closer! C1549 looked like it might have been replaced with a mylar
cap. As soon as I unsoldered one side and turned on the scope, the fan came
on! So i replaced it with a 47mf 25 v electrolytic and now had a bit of a
trace but way off vertical axis. Good call Albert!
The voltages now are112.5, 55.66, 15.1, 4.9 and -6.4
I see that the vertical axis is associated with the -8 rail and read the
troubleshooting for vertical axis anomalies but before I go further I thought
I check for advice here first.
Thanks in advance, Russ
|
Re: What are these Tek parts for?
OK. It appears you are correct about the left part. I now realize that my
OS-245 (milspec 7603) .... But the other part pictured does not match up to anything I can tell. Could it be the front of a chart recorder like these? Tom Bryan
|
Re: What are these Tek parts for?
OK. It appears you are correct about the left part. I now realize that my OS-245 (milspec 7603) is missing the receiving side of the clips to which the cover attaches. I've added photos to the aforementioned online image album <>. So, I'd like to find those clips if someone know where I can get them. Either that, or I'll have to fabricate them. I bump into these sorts of clips all the time (trying to think if there something around the house I can harvest them from). But the other part pictured does not match up to anything I can tell. On Mon, Jul 2, 2018 at 6:43 AM, Colin Herbert via Groups.Io < colingherbert@...> wrote: One of those looks like the front cover for a series-7000 scope (option
#8). It even still has the foam bits for holding probe parts. I've no idea
what the other thing is, but could it be some kind of implosion screen?
Colin.
-----Original Message-----
From: [email protected] [mailto:[email protected]] On Behalf Of David
Berlind
Sent: 02 July 2018 02:14
To: [email protected]
Subject: [TekScopes] What are these Tek parts for?
Two parts... some sort of cover.. but I don't think it's for anything I
own. Smells like an old Tek scope too! If I have no need for this and
someone else does, I'd be happy to stick it in a box if you cover postage.
|
Re: 7912AD Fails start-up self-test (perhaps)
On Sun, Jul 1, 2018 at 02:46 pm, Adrian wrote: So as of a few hours ago I became the proud owner of a 7912AD with a matched
pair of 624 & 634 monitors. Congratulations and welcome to the club. I believe I should see the 'Remote' and 'Digital' lights come on for two
seconds followed by the 'TV' and 'Local' lights coming on but all I see is two
brief flashes of the 'Reduce Intensity' LED, a short pause, a third flash then
nothing.
My question is: Does the self-test actually flash that LED (it is not
mentioned in the manual as far as I can see) or does the fact that it comes on
at all mean that the system is sensing a high intensity somehow and aborting I've just made a couple of short movies of my 7912AD waking from its slumber. The lights change as you describe and the 'reduce intensity' LED does flash in the pattern you mention. First a view of the whole thing (sorry about the horrid little LCD monitor, but it's all that will fit on the bench): Then a closeup of the buttons and lights: In my experience failure to start up has most usually been caused by missing/incorrect power supply rails. There's a circuit which monitors most of them and holds the 6800 CPU in reset until they're right. Bringing a wire out from the 6800's reset pin and watching what happens to it might be interesting. If the self-test is failing for other reasons (RAM or ROM test error) then that gets shown on the TV's readout. The last time my 7912AD stopped working, it was because there was a poor contact on a harmonica connector on the PSU regulator board which fed -2V to the power distribution board. That was enough to stop play. Chris
|
Re: 7912AD Fails start-up self-test (perhaps)
Adrian,
The 'reduce intensity' light can be triggered either by current in the write gun measured via the A1 electrode (diagram <7>, A40 board, signal is labelled 'Protect Enable' and drives 'reduce Intensity' via U114 on diagram <12>) or by the CPU via U830 on diagram <13>. In fixing my 7912AD I was fooled by the Reduce Intensity light making me think there was write current when in fact the 10kV anode voltage to the write gun had failed.
The symptoms you describe suggest that the 6800 MPU is not working properly and if the DC level of +5.1V is correct then check also for ripple. The installation of the many plugin boards into the backplanes makes for difficult testing at the board level without extenders (I have never seen any advertised). I would be tempted to solder in a few flying leads so that you can check CPU clock and busses (and reset) and work from there.
There is a handy trick to check if the read gun and video circuitry are OK - it can be found under the calibration section of the manual. Reverse the current through the focussing coil of the read gun and you should get a bright ring around the edge of the display. This is independent of anything written to the target.
Regards,
Roger
|
Re: What are these Tek parts for?
One of those looks like the front cover for a series-7000 scope (option #8). It even still has the foam bits for holding probe parts. I've no idea what the other thing is, but could it be some kind of implosion screen?
Colin.
toggle quoted message
Show quoted text
-----Original Message----- From: [email protected] [mailto: [email protected]] On Behalf Of David Berlind Sent: 02 July 2018 02:14 To: [email protected]Subject: [TekScopes] What are these Tek parts for? Two parts... some sort of cover.. but I don't think it's for anything I own. Smells like an old Tek scope too! If I have no need for this and someone else does, I'd be happy to stick it in a box if you cover postage.
|
Interesting stuff, thanx!!
|
Here's some photos of the 568 & 3T6 I got from a local Surplus Store.
They're pretty crappy photos the Sun is going down but somebody wanted to
see them.
I wish I still had my mod sheets of all the different S3100 mods and mods
to the 568 3T6/3S6 we did for the S3200 family.
I guess just more things to figure out.
Plug-in wise it's starting to look like getting a clean 3S6 might be an
issue.
toggle quoted message
Show quoted text
On Sun, Jul 1, 2018, 1:51 PM Pete Lancashire <xyzzypdx@...> wrote: It's going to be a big project I hope to be able to complete at least parts
of it so that whoever may take it on after me will not have a hard time
finishing it ?
Very few people know the history of ATE Tektronix was decades ahead of
everybody else. And also made a bundle of money in the process.
Unfortunately almost everybody involved got no recognition.
On Sun, Jul 1, 2018, 11:09 AM Miguel Work <harrimansat@...> wrote:
Amazing, please photos!!!
-----Mensaje original-----
De: [email protected] [mailto:[email protected]] En nombre de Pete
Lancashire
Enviado el: domingo, 1 de julio de 2018 18:00
Para: [email protected]
Asunto: [TekScopes] s3100 restoration
I acquired a very clean 568 & 3T6 yesterday. Pictures by end of day.
Registered S3100.org
Put offers on 2 x sampling head extenders and were accepted.
Need / looking for
- Plugin paddle boards, or one I can use to get boars made
- Board extenders for the inside boards in the 3T6
- P/N for the interconnect cables and cables
- A-3A heads and accessories.
- R241 & cards, etc.
- S3110 rack. there must be on in the Beaverton/Portland area, Even the
name plate would be nice.
- Test drawer, dut holder etc
- Integration manual (interconnect) not needed but would be nice to
have, does give p/n's for all cables.
Next week will be picking up at least one mouse poop covered R230 and at
least two R568s for parts.
|
What are these Tek parts for?
Two parts... some sort of cover.. but I don't think it's for anything I own. Smells like an old Tek scope too! If I have no need for this and someone else does, I'd be happy to stick it in a box if you cover postage.
|
On 2018-07-01 5:38 PM, HankC, Boston, WA1HOS via Groups.Io wrote:
Found this on the Vintage Tek website I found it extremelyinteresting.
This really is a gem and quite revealing of the attitudes and thoroughness that promoted Tektronix quality. Thanks for the link. --Toby
HankC, Boston WA1HOS
|
Looking for Rare Trace Rot/Trace Sep Pot for 556
Part number is 311-0595-00
It's 3 potentiometers... two 500 kohm pots, and one 10 kohm pot.
If I'm unable to find this potentiometer, anyone have any ideas what sort of modern thing I could replace it with? I have access to a machine shop if that helps.
|
Re: K213 Instrument Cart Drawer Jammed
I kind of doubt that it is painted metal on painted
metal.
Every scope cart drawer that I have seen has a few
holes at their ends that hold little plastic buttons
that the drawer glides on. They don't become painted
metal on painted metal until the nylon/delrin buttons
disintegrate.
-Chuck Harris
Jim Hill wrote:
toggle quoted message
Show quoted text
After much fiddling around, I managed to close the drawer, put the scope on it's side
and remove the bottom plate. There is nothing sophisticated like tabs to move when
removing the drawer. It is just painted metal sliding on painted metal. I'm unable
to remove the drawer, but fortunately don't need to do so. The drawer just binds when
attempting to open or close, and if you give it a good try, it jams. I will try
using paste floor wax on the sliding surfaces and see if that helps.
Jim
At 05:24 PM 6/29/2018, Michael A. Terrell wrote:
Are there locks on the drawer slides that drop into place when you pull it all thew
way out? If so you push in on them, while closing the drawer.
Michael A. Terrell
|
7912AD Fails start-up self-test (perhaps)
So as of a few hours ago I became the proud owner of a 7912AD with a matched pair of 624 & 634 monitors.
The inevitable puff of smoke led me to a hot 10R resistor and thus the equally inevitable shorted blue tant (why is it nearly always the blue ones that die but only rarely the yellow ones?) on the +15V rail on A38 Scan board. Once that was fixed things seemed ok power-wise, or at least all voltages looked ok on the PSU test points, the fan runs up but we don't get much further.
I believe I should see the 'Remote' and 'Digital' lights come on for two seconds followed by the 'TV' and 'Local' lights coming on but all I see is two brief flashes of the 'Reduce Intensity' LED, a short pause, a third flash then nothing.
My question is: Does the self-test actually flash that LED (it is not mentioned in the manual as far as I can see) or does the fact that it comes on at all mean that the system is sensing a high intensity somehow and aborting the start-up? - and yes, the two intensity pots are set at minimum.
Right now I'm thinking it could be the A10 front panel and A22 'Translator' boards need looking at ..... but I'm still wading through 400+pages of manual......
Adrian
|
Fabio Trevisan