Tektronix TDS754D 4ch Sampling Scope Input Problems

[CommandoBot]

Hello,

I own a Tektronix TDS754D 4 channel sampling scope. Unfortunately
three of the four channels are showing wrong voltage levels. I already
took some measurements on the aquisition board. For me it looks like
the input amplifier ceramic circuit boards already produce the error.
The LVD signal which is routed to the main sampling board already
seems to be faulty. But since the voltages are very low I can't
guarantee that there are no measurement errors. Besides the wrong
level the signals seem to float also. When changing the offset for
displaying the signals they are not always on the same level compared
to the ground line.

Does anybody have some contact information / spare parts /
schematics / manuals ... ? ... Anything that might help in fixing the
scope? Repair shops should be located in Germany ... shipping this 30+
kg scope Internationally is no good idea ... I guess ...

The Tektronix repair facillity is not an option for me. They request
EUR 3333,- for this type. (No joke ;o) ) ...

Thanks and best wishes,


CommandoBot

 

[Jim Yanik]

Hello,

I own a Tektronix TDS754D 4 channel sampling scope. Unfortunately
three of the four channels are showing wrong voltage levels. I already
took some measurements on the aquisition board. For me it looks like
the input amplifier ceramic circuit boards already produce the error.
The LVD signal which is routed to the main sampling board already
seems to be faulty. But since the voltages are very low I can't
guarantee that there are no measurement errors. Besides the wrong
level the signals seem to float also. When changing the offset for
displaying the signals they are not always on the same level compared
to the ground line.

Does anybody have some contact information / spare parts /
schematics / manuals ... ? ... Anything that might help in fixing the
scope? Repair shops should be located in Germany ... shipping this 30+
kg scope Internationally is no good idea ... I guess ...

The Tektronix repair facillity is not an option for me. They request
EUR 3333,- for this type. (No joke ;o) ) ...

Thanks and best wishes,


CommandoBot

TEK never supplied REAL service manuals with component-level schematics for
the TDS series,except for a few models that the US Military specified have
schematics as part of their purchase contracts,and shipped with the
scopes.Those manuals were US Mil part numbered,not the usual TEK
manuals,and only TEK and the US Mil would know which models they were.

TEK did not intend that outsiders service the TDS product line.

Also,check the Long Term Product Support(LTPS) list to see if your model is
still supported. It may be "obsolete",and only cal service offered.

(and the astronomical service prices are set that way to "encourage"
customers to buy new instruments to replace the "obsolete" units,that TEK
no longer desires to support.)

 

[Andrew]

TEK never supplied REAL service manuals with component-level schematics for
the TDS series,except for a few models that the US Military specified have
schematics as part of their purchase contracts,and shipped with the
scopes.Those manuals were US Mil part numbered,not the usual TEK
manuals,and only TEK and the US Mil would know which models they were.

TEK did not intend that outsiders service the TDS product line.

Also,check the Long Term Product Support(LTPS) list to see if your model is
still supported. It may be "obsolete",and only cal service offered.

(and the astronomical service prices are set that way to "encourage"
customers to buy new instruments to replace the "obsolete" units,that TEK
no longer desires to support.)

Jim, do you have any of those cross references?

Andrew

 

[Jim Yanik]

Jim, do you have any of those cross references?

Andrew

No,I had to leave all reference material behind when I left TEK.(company
confidential)
you can check the LTPS list at www.tek.com

 

[CommandoBot]

Hi

First of all thanks for your answer ...

TEK never supplied REAL service manuals with component-level schematics for
the TDS series,except for a few models that the US Military specified have
schematics as part of their purchase contracts,and shipped with the
scopes.Those manuals were US Mil part numbered,not the usual TEK
manuals,and only TEK and the US Mil would know which models they were.

I thougt so already. Now I know for sure ( ...

Also,check the Long Term Product Support(LTPS) list to see if your model is
still supported. It may be "obsolete",and only cal service offered.

I was looking at the LTPS located on the Tektronix WEB side.
The model TDS754D still is in full service. So to have it repaired at
the
German Tektronix location would be possible. But for me it is no
option
unfortunately. The price is too high (EUR 3333,-).

(and the astronomical service prices are set that way to "encourage"
customers to buy new instruments to replace the "obsolete" units,that TEK
no longer desires to support.)

That might be true. But a new scope (at least of this kind) for
private use
is a little bit too expensive as well.
I got it quite cheap from the company I am working it. But I was told
two channels
are broken. But when I checked it out actualle three channels didn't
work properly.
I am working quite alot with FPGAs and Video signals. And since this
specific
scope even has the video trigger software option installed .... it is
perfect. But
I have to measure red, green and blue one after the other instead of
all of them
together ( ...

So I still hope for some affordable solution for fixing the scope.
Maybe somebody
has a scope with the µC / Video board broken ... or burned up power
supply ...
or whatsoever ... who might want to sell me the input amplifiers or
the aquisition
PCB ... I am quite sure everything else with the scope is fine.

Best wishes

CommandoBot

 

[Jim Yanik]

Hi

First of all thanks for your answer ...


I thougt so already. Now I know for sure ( ...


I was looking at the LTPS located on the Tektronix WEB side.
The model TDS754D still is in full service. So to have it repaired at
the
German Tektronix location would be possible. But for me it is no
option
unfortunately. The price is too high (EUR 3333,-).


That might be true. But a new scope (at least of this kind) for
private use
is a little bit too expensive as well.
I got it quite cheap from the company I am working it. But I was told
two channels
are broken. But when I checked it out actualle three channels didn't
work properly.
I am working quite alot with FPGAs and Video signals. And since this
specific
scope even has the video trigger software option installed .... it is
perfect. But
I have to measure red, green and blue one after the other instead of
all of them
together ( ...

So I still hope for some affordable solution for fixing the scope.
Maybe somebody
has a scope with the µC / Video board broken ... or burned up power
supply ...
or whatsoever ... who might want to sell me the input amplifiers or
the aquisition
PCB ... I am quite sure everything else with the scope is fine.

Best wishes

CommandoBot

IF you know what assembly is the problem,you can send that assembly in for
"repair and return".I don't know how it would be priced,you'd have to call
the service center and inquire. BUT,if they are anything like the USA TEK
service center,there's a fair chance they will LOSE your assembly.

also,you would need to recal the instrument afterwards.