[Newbie] help to revive 1988 GPIB-232CV

[Von_Bednar]

Hi all - a newbie here with a problem

I got a vintage (the board is dated 1988) GPIB-232CV (not -A) 64K adapter that I wanted to use to connect my HP 7475A plotter to a modern PC. I connected power to the adapter today to test it - it came on with all LEDs fully lit up. After around 2-3s I smelled smoke, so I disconnected quickly.

I openned the case and it seems the board is in a good condition, but one of the capacitor has blown (seen in the photo in lower right - C40). I am hoping to fix it (can't afford a new adapter on a student budget), but it seems I can't find a service manual for this particular model (the model doesn't even show on NI website). I am hoping someone has a copy of a service manual or know what capacitor was at C40 so I can replace it.

I suspect the core problem was a faulty power supply, so I am hoping to get a modern PSU connected after I deal with the capacitors. However, maybe all the LEDs being lit up on power on is a known code that points to some other issue.

Any help would be greatly appriciated.

Edit with some more (possibly helpful) into:

Device name on the bottom label: GPIB-232CV 64K

Part number on the case: 180455-01 rev b

Part number on the board: 180367-01 rev b

S/N: 356

[Von_Bednar]

Sorry for replying to myself, but I can't edit the original post anymore...

I would also love to know what size plug would I need for the power supply - it doesn't seem to be included in the user manual (maybe it can be found in service manual?).

[Von_Bednar]

An update, as others might find it helpful in the future.

After getting some help from other engineers and analyzing the board, we have identified that the C40 cap is 99% the same as the one on C18. Those are the only two components that share shape and color, and the drawing on the board is the same. After de-soldering C18 we have found that it can be replaced with: T322A105K025AT7200  from KEMET.

Also, it seems that C40 is there to reduce noise on switching, so it is not essential.

After soldering c18 back on and getting a new power supply it seems the board is working (power, ready and listen lights stay lit) - I am waiting for a cable to confirm 100%

The manual says that power & ready should stay lit. Is it normal for LISTEN to also be on when nothing is connected either to serial of GPIB in controller mode?

[Von_Bednar]

I got all the cables needed, but I am unable to connect to it via Serial. I have few questions and hope someone who has a GPIB-232CV can answer those:

• Can I connect to the GPIB-232CV via serial terminal even if no device is connected?
• Should my serial terminal return any text on successful connection? (currently it seems "stuck" not returning anything and not accepting input)
• Is having either LISTEN or TALK lit up after power-on test normal. It happens in some DIP switches configurations (either C or D). The other configuration lights up only POWER and READY.
• On the rocker dip switches inside is pressed IN or OUT as active (so if the dip switch is pressed in next to OFF, is it in OFF position or ON)? See the attached picture for the dip switch type. Are 1&2 on both blocks considered ON or OFF?