开云体育

Hello all,

I have been a group member for a while although not an active one, I recently bought a TDS 544A and TDS 540 cheapish.

Work has started on the 544A it used to:
FAIL++Acq/Proc Intf,
FAIL++Acquisition,
FAIL++Attn/Acq Intf.

The Acquisition board has been recapped, dish-washed and scrubbed down twice with a mildly basic soap (pH 8.1), corrosion was quite severe around the "time interpolator and jitter ramp" section, many cut traces.

Now I get:
FAIL++Acquisition

It will not pass SPC either, failing on signal path.
The most recent error logs are:

(For POST) ERROR diagnostic test failure
ctlConfidenceDiag 2.50e-9<=exp<=1.20e-8 actual 1-something

(For SPC) ERROR 2260 Calibration failed
Repet Cal Failed




The scope is otherwise working quite well, not too far off cal, CH1 is slightly out, CH1 & CH4 are slightly noisier than CH2 & CH3 even when grounded.


I do not have GPIB to access the full error messages.


Any clues on what could be causing those errors are welcome.


Paul

Keep looking for corrosion damage like a component connection or opened run, or remaining crud (especially on/between IC leads) that you may have missed. An old toothbrush is good for scrubbing. It's best to wash the board again after removing the old caps, before putting in the new ones. Also, double check the polarities to be sure none are backwards.

I went through the same thing a while back - fortunately, it worked after thorough washing and scrubbing. I have stripped all the old Al SMT caps but not yet installed the replacement Ta ones - it works as-is, even without them.

Ed

Hi Paul,

Just checking you know that the schematic are now available. It can be pretty helpful when tracks have gone missing.


I had a similar issue with a TDS544a and found that wire replacing a missing via under U1652 fixed the ERROR: diagnostic test failure, ctlConfidencDiag, ** 2.50e-9 <= exp <= 1.20e-8 actual= 2.38e-7 delay TI failed". U1652 is a TL072 over near the fan.



I still have a single error: logicTrigConfDiag, STRIGA must be HI when triggered, wasn't for gamma comparator" which I can't seem to trace down. STRIGA connects through from the correct pins but the scope works fine even with this error.


Best of luck with your repair,


Simon

Hello,

Ed:

Checking over and over again was my default option, I was hoping that a
firmware that logs so many detailed error messages could actually be useful
to probe the problem down on a narrowed section of the acquisition board.

I took photos, removed all the leaky caps then washed it down. The
replacement caps are MLCC so no polarity to worry about.

Does yours work well, good noise floor and no issues at higher sampling
rates without the caps?


Simon:

I have the .zip schematic from Didiers site is there a better one than that
about?

There were plenty of cut traces on mine under U1602 and U1652, I replaced
U1602 by a TL072C it was originally a MC34002, assuming it was a good
enough substitute as the schematic has TL072s.

I measured -6.85V at TP1608 and -7.25V at TP1658 should the -5.9V quoted in
the schematic be spot-on here?


Thanks,

Paul



2016-03-23 17:12 GMT+01:00 edbreya@... [TekScopes] <
TekScopes@...>:

I got a pdf of the TDS544A service info from Hakan's (sp?) website, which someone referred me to back when I started. It's the only one I've seen, and it does have the board layout info so you can print (multiple pages) and use for recapping reference.

I'm not sure how well mine works spec-wise without replacing the caps, but it seems to be just fine operationally - I just wanted to indicate how robust it is once all the runs and parts are rescued from the old cap leakage. I do plan to replace them - I have a small plastic bottle with plenty enough SM Ta caps set aside, and marked up board layout prints, for when I get the time and inclination. There are a lot of ceramic bypass caps spread around the board for RF and high frequency stuff. The larger electrolytics are presumably for lower frequency like power supply noise and ripple, so they should be beneficial.

The problem with mine is that the HVPS transformer for the CRT burned out shortly after I got everything working, so I just use it with an external VGA display, which is actually quite nice.

Ed

TL074/TL072 work fine. Glad the schematics have made it to KO4BB.

I'm not too sure what the voltages should be at those test points. I would strongly suggest tying to find a GPIB adaptor somehow as it makes this debugging quite a lot easier. I had problems with the error log getting too long to find the latest errors.


Even if the traces looks like they are connected make sure to check them with a multimeter for continuity.


Simon

Hello,

Quick and late (here) update:

The TDS544A had been put aside a while, the TDS540 passed self tests but
needed a recap for A11 and A12 boards, A10 had been taken care of by
someone before things turned bad.
Now I have a working scope to confront the failing TDS544A with.

The test point TP1608 is at -6.72V, TP1658 at -6.74V in the working scope.
Just for future reference.

What would be a good choice/source for a budget USB GPIB interface?
Avoiding fakes.


Paul

2016-03-25 9:00 GMT+01:00 kennedy.simon@... [TekScopes] <
TekScopes@...>:

I realized there were too many conditions in the GPIB interface question...

My problem on the TDS544A turned out to be a cut trace under VR1664.

Both TP1608 and TP1658 are now at -6.73V, still not the values on the
schematic, they are similar on both working scopes though.


I had dumped the NVRAM (Desoldered and socketed) on the 544A before
recaping, since I have read here that it is not uncommon that the NVRAMs
die on desoldering, is it worth the risk dumping the TDS540 NVRAM too?

Now the scopes are working is there a simple way to enable options software
options? (Still no GPIB)

Thanks,

Paul

2016-03-26 2:39 GMT+01:00 paul huguenin <tigrol.lechat@...>:

Hey Paul,

Congrats on the fix.
Do you have the field adjust software for your scopes? The FAS for my TDS
784D declares the addresses/locations for the software option flags in a
config file of some sort. There are threads on the Tek forum on how to
apply those with a serial console connection and GPIB (I forget the
details).

Siggi
On Sat, Mar 26, 2016 at 19:39 paul huguenin tigrol.lechat@...
[TekScopes] <TekScopes@...> wrote:

I realized there were too many conditions in the GPIB interface question...

My problem on the TDS544A turned out to be a cut trace under VR1664.

Both TP1608 and TP1658 are now at -6.73V, still not the values on the
schematic, they are similar on both working scopes though.

I had dumped the NVRAM (Desoldered and socketed) on the 544A before
recaping, since I have read here that it is not uncommon that the NVRAMs
die on desoldering, is it worth the risk dumping the TDS540 NVRAM too?

Now the scopes are working is there a simple way to enable options software
options? (Still no GPIB)

Thanks,

Paul



2016-03-26 2:39 GMT+01:00 paul huguenin <tigrol.lechat@...>:

Hello,

Quick and late (here) update:

The TDS544A had been put aside a while, the TDS540 passed self tests but
needed a recap for A11 and A12 boards, A10 had been taken care of by
someone before things turned bad.
Now I have a working scope to confront the failing TDS544A with.

The test point TP1608 is at -6.72V, TP1658 at -6.74V in the working

scope.

Just for future reference.

What would be a good choice/source for a budget USB GPIB interface?
Avoiding fakes.


Paul

2016-03-25 9:00 GMT+01:00 kennedy.simon@... [TekScopes] <
TekScopes@...>:

TL074/TL072 work fine. Glad the schematics have made it to KO4BB.

I'm not too sure what the voltages should be at those test points. I
would strongly suggest tying to find a GPIB adaptor somehow as it makes
this debugging quite a lot easier. I had problems with the error log
getting too long to find the latest errors.


Even if the traces looks like they are connected make sure to check them
with a multimeter for continuity.


Simon






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Posted by: kennedy.simon@...
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------------------------------------

Yahoo Groups Links

[Non-text portions of this message have been removed]

Hello,

Thanks Siggi, I must admit that was a little steep for a first experience
on a Tek DSO.

I have found the FAS for the TDS544A on KO4BB, run it on Windows 7 with
DOSbox emulator, from what I see it will only use two models of 8bit ISA NI
GPIB cards.
It seems a shame to find an old 90's card just for that purpose when I have
not yet invested in a recent GPIB interface.
There was nothing obvious in terms of software options in the config files,
it could be stored in main .EXE for this older version.

The most convenient for me would either be directly editing the NVRAM with
a programmer or using RS232 somehow. Shouldn't all that is done with GPIB
be possible with the serial console too?

The other problem is the calibration, DC balance seems to need adjusting,
the mean values measured by the scope change depending on horizontal range
and position (offset) on the screen, any way I can work around that without
the antique FAS and required hardware?

Paul

2016-03-27 1:27 GMT+01:00 Sigur?ur ?sgeirsson siggi@... [TekScopes] <
TekScopes@...>:

Hey Paul,

Congrats on the fix.
Do you have the field adjust software for your scopes? The FAS for my TDS
784D declares the addresses/locations for the software option flags in a
config file of some sort. There are threads on the Tek forum on how to
apply those with a serial console connection and GPIB (I forget the
details).

Siggi
On Sat, Mar 26, 2016 at 19:39 paul huguenin tigrol.lechat@...
[TekScopes] <TekScopes@...> wrote:

I realized there were too many conditions in the GPIB interface

question...

My problem on the TDS544A turned out to be a cut trace under VR1664.

Both TP1608 and TP1658 are now at -6.73V, still not the values on the
schematic, they are similar on both working scopes though.

I had dumped the NVRAM (Desoldered and socketed) on the 544A before
recaping, since I have read here that it is not uncommon that the NVRAMs
die on desoldering, is it worth the risk dumping the TDS540 NVRAM too?

Now the scopes are working is there a simple way to enable options

software

options? (Still no GPIB)

Thanks,

Paul



2016-03-26 2:39 GMT+01:00 paul huguenin <tigrol.lechat@...>:

Hello,

Quick and late (here) update:

The TDS544A had been put aside a while, the TDS540 passed self tests

but

needed a recap for A11 and A12 boards, A10 had been taken care of by
someone before things turned bad.
Now I have a working scope to confront the failing TDS544A with.

The test point TP1608 is at -6.72V, TP1658 at -6.74V in the working

scope.

Just for future reference.

What would be a good choice/source for a budget USB GPIB interface?
Avoiding fakes.


Paul

2016-03-25 9:00 GMT+01:00 kennedy.simon@... [TekScopes] <
TekScopes@...>:

TL074/TL072 work fine. Glad the schematics have made it to KO4BB.

I'm not too sure what the voltages should be at those test points. I
would strongly suggest tying to find a GPIB adaptor somehow as it

makes

this debugging quite a lot easier. I had problems with the error log
getting too long to find the latest errors.


Even if the traces looks like they are connected make sure to check

them

with a multimeter for continuity.


Simon


[Non-text portions of this message have been removed]



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Posted by: kennedy.simon@...
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------------------------------------

Yahoo Groups Links

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Posted by: =?UTF-8?B?U2lndXLDsHVyIMOBc2dlaXJzc29u?= <siggi@...>
------------------------------------


------------------------------------

Yahoo Groups Links

[Non-text portions of this message have been removed]

Hey Paul,

sorry to confuse the issue. I don't think the FAS will enable or disable
options for you. It may however (I've never looked at the TDS540 FAS) declare
the memory location of the byte that holds the flag.
Sadly it appears that Tek is scrubbing their forum of the details, but
here's an EEVBlog thread <
(tds754d)/>
for how this might be done through the serial console. Here's <
>
a similar thread on EEVBlog for how to use GPIB.
It appears the addresses are the same whether you use GPIB or a console
serial port, but the "poke" command is different depending on the mode of
access. If you want to write to the NVRAM directly, presumably you need to
find it's base address in the processor's address space and subtract that
from the address.

As for how to come by these addresses, in e.g. the TDS784D FAS, I see
config files named by the scope types. In a file named TDS784D.CON,
containing lines such as "VAR = hwAOption1M(UNIT "" VALUE 327686)" which
relates the address of the 1M option flag (327686 decimal is 0x50006 hex). It's
possible that the options are always at the same address, scope model and
age be damned, but I don't know that. If your FAS declares this somewhere
for your scope's type, that'd be a good place to nab it.

Caveat: I've never done any of the above.

Siggi

On Mon, 28 Mar 2016 at 17:51 paul huguenin tigrol.lechat@...
[TekScopes] <TekScopes@...> wrote:

Hello,

Thanks Siggi, I must admit that was a little steep for a first experience
on a Tek DSO.

I have found the FAS for the TDS544A on KO4BB, run it on Windows 7 with
DOSbox emulator, from what I see it will only use two models of 8bit ISA NI
GPIB cards.
It seems a shame to find an old 90's card just for that purpose when I have
not yet invested in a recent GPIB interface.
There was nothing obvious in terms of software options in the config files,
it could be stored in main .EXE for this older version.

The most convenient for me would either be directly editing the NVRAM with
a programmer or using RS232 somehow. Shouldn't all that is done with GPIB
be possible with the serial console too?

The other problem is the calibration, DC balance seems to need adjusting,
the mean values measured by the scope change depending on horizontal range
and position (offset) on the screen, any way I can work around that without
the antique FAS and required hardware?

Paul

2016-03-27 1:27 GMT+01:00 Sigur?ur ?sgeirsson siggi@... [TekScopes] <
TekScopes@...>:

Hey Paul,

Congrats on the fix.
Do you have the field adjust software for your scopes? The FAS for my TDS
784D declares the addresses/locations for the software option flags in a
config file of some sort. There are threads on the Tek forum on how to
apply those with a serial console connection and GPIB (I forget the
details).

Siggi
On Sat, Mar 26, 2016 at 19:39 paul huguenin tigrol.lechat@...
[TekScopes] <TekScopes@...> wrote:

I realized there were too many conditions in the GPIB interface

question...

My problem on the TDS544A turned out to be a cut trace under VR1664.

Both TP1608 and TP1658 are now at -6.73V, still not the values on the
schematic, they are similar on both working scopes though.

I had dumped the NVRAM (Desoldered and socketed) on the 544A before
recaping, since I have read here that it is not uncommon that the

NVRAMs

die on desoldering, is it worth the risk dumping the TDS540 NVRAM too?

Now the scopes are working is there a simple way to enable options

software

options? (Still no GPIB)

Thanks,

Paul



2016-03-26 2:39 GMT+01:00 paul huguenin <tigrol.lechat@...>:

Hello,

Quick and late (here) update:

The TDS544A had been put aside a while, the TDS540 passed self tests

but

needed a recap for A11 and A12 boards, A10 had been taken care of by
someone before things turned bad.
Now I have a working scope to confront the failing TDS544A with.

The test point TP1608 is at -6.72V, TP1658 at -6.74V in the working

scope.

Just for future reference.

What would be a good choice/source for a budget USB GPIB interface?
Avoiding fakes.


Paul

2016-03-25 9:00 GMT+01:00 kennedy.simon@... [TekScopes] <
TekScopes@...>:

TL074/TL072 work fine. Glad the schematics have made it to KO4BB.

I'm not too sure what the voltages should be at those test points. I
would strongly suggest tying to find a GPIB adaptor somehow as it

makes

this debugging quite a lot easier. I had problems with the error log
getting too long to find the latest errors.


Even if the traces looks like they are connected make sure to check

them

with a multimeter for continuity.


Simon


[Non-text portions of this message have been removed]



------------------------------------
Posted by: kennedy.simon@...
------------------------------------


------------------------------------

Yahoo Groups Links

[Non-text portions of this message have been removed]

[Non-text portions of this message have been removed]



------------------------------------

Posted by: =?UTF-8?B?U2lndXLDsHVyIMOBc2dlaXJzc29u?= <siggi@...>

------------------------------------


------------------------------------

Yahoo Groups Links

[Non-text portions of this message have been removed]

Hey y'all,

seems that Tek may not be scrubbing their forums as I'd assumed. You can
still search them directly for relevant terms like <
> or e.g. <
>. They seem to have
somehow wiggled out from underneath the links in Google search, though.

Siggi

Hello all,

Siggi:
I had also noticed that all the google links to the Tek forum returned "The
requested topic does not exist." - not so convenient.

Thanks for your clues on enabling SW options, the .zip files I downloaded
contain no .CON files, they do contain .IDX files for each supported TDS
scope, the .IDX only seem to call the adequate module for different
calibration steps.

DOSbox emulator is not good enough (or not configured properly) to allow a
full install of the calibration software that may create some .CON files,
I'll have to knock an old PC together to try it out, then it will seem a
shame to not have the required GPIB card... That could keep me busy another
couple of months.
I may not keep these oscilloscopes in the end, they are not bad but I much
prefer the LeCroy UI.

Paul

I like the BEIMING adapters, since they are genuinely not HP.
However their website appears to be offline, so....

The fakes are pretty good. I'd rather buy from someone who didn't
invest any effort into making it a credible fake but I have one fake
(bought used) and it works just fine.

ST


On Sat, Mar 26, 2016 at 2:39 AM, paul huguenin tigrol.lechat@...
[TekScopes]