Electronics > Repair
Repair : HP 3245A precision DC/AC source
<< < (28/29) > >>
PartialDischarge:

--- Quote from: rastro on March 14, 2020, 03:01:41 pm ---The PCB's are a pain to remove - lot of jiggle and sliding.  There should be a procedure in the manuals as I recall.  Check for PDF's on line. 

--- End quote ---

They are pretty easy actually, the trick is to remove the lateral screws that hold the metal plate. Then this metal plates shifts both upper and lower boards out of the connector
JesseLackey:
So nice to have your help rastro and mastertech!  I was able to remove the boards, I'm not sure removing the metal plate was actually necessary but it allowed everything to be more jiggle-able and it was then easy.
I'm taking apart the working unit of the 3 so all fuses are fine (I continuity checked just to be sure), but that is a great tip, I'll get some for the other two units.

Any thoughts on the DS1235YW-150?  I'm going to need 6; octopart.com comes up with only 2 places with the full part number.
Is there a recommended (by eevblog people, not Maxim, where you can't even get the datasheet it looks like) replacement?

<https://www.maximintegrated.com/en/design/technical-documents/app-notes/2/202.html> has some good info I'm looking at.
also: <https://www.avsforum.com/forum/16-crt-projectors/246228-what-replace-dallas-ds1235yw-150-a.html>

I'm about to buy a power duster too, the "metrovac datavac" was recommended in a post on eevblog, but the "Compucleaner 2.0" is substantially cheaper and has good amazon reviews.  My air in a can is now just an empty can and I decided no more cans.

Tx all!
J

Update: from the maxim appnote referenced above:
"What's a DS1235?
A number of years ago, Dallas Semiconductor® had a 256kb NV SRAM product called the DS1235. It was functionally and physically identical to the DS1230, with the exception that the DS1235 had a five-year data-retention expectation instead of 10 years. An alternative is the DS1230 with the same power-supply tolerance, and with a performance rating equal to or faster than the original DS1235 product (for example, the DS1235Y-150 should be replaced by a DS1230Y-70+)."

So there we have it!
J

JesseLackey:
Hi Alan, firstly thank you so much for all your info regarding the HP 3245A.  It gave me confidence to buy & work on rebuilding/repairing no less than 3 of them (simultaneously!)

I just today got GPIB going with a new NI USB<->GPIB converter, and your calibration app (V0.2) was able to see the HP 3245A.  A great first step.

I'm about to order a GPIB "splitter" so that I can talk to the HP 3245A and a HP 34401A simultaneously.  I don't have a HP 3478 but the 34401A can emulate it, apparently nearly completely.
(I do have an Avantest R6581T w/NIST cal, but it is DC V/I only, no AC).

2 questions for you ...
Is there a more recent version of your app?  The 0.2 was the latest on your site.
Are you willing to share source code?  Being able to tweak it could be very helpful; I have visual studio and long experience with C/C++ and a little with python.  I assume this is C.  Modifying it to use my R6581T for the DCV/DCI portion would be pretty fun... and having code like this is a great starting point for further GPIB adventures.

Many thanks in advance!
J


Omicron:

--- Quote from: rastro on September 28, 2019, 12:01:55 am ---Has anyone found a replacement source/part for C900 on the source boards.  This is the 470uF/25V radial electrolytic with an additional ground lead (screen?) at the top?

--- End quote ---

Did anyone find a good replacement for this cap? Is the 3rd lead just there as a mechanical support or is it indeed used for a screen?
Samogon:
I just used regular radial capacitor, bent connector and glued to PCB with 704 silicon rubber glue.
Navigation
Message Index
Next page
Previous page
There was an error while thanking
Thanking...

Go to full version
Powered by SMFPacks Advanced Attachments Uploader Mod