No big troubleshooting here, the HP3312A function generator had been developing small fault over time, the last time I used it was not outputting signal or with the wrong shape, so decided to see what could be done.

This was the "sinusoidal" output:

 

Not good! Also the frequency was not in line with the bezel markings.

Here's the offending component on top board near the front panel.

I just guessed it was the one causing the issue, the crack was easy to spot.

The reference marked in the capacitor, if needed:

TRW 8508
HEW-331
.5MF +/- 10%
50 VDC

Better now after replacement, I didn't had 0.5MF as originally so by mistake placed a 2.2uF, got better but still some distortion seen:

 

 I then replaced by a 1uF one and now it's perfect, in the future I will probably try to find the right value (0.5uF) and replace.

Have a nice day!

 I've done a previous repair on this device because I got it without being working on the 18Ghz range. I suspect this will not be the last one given it's age.

Anyhow, one of this days I turned it on to check the output frequency of a FVC99 module and it was displaying all entrance selector LED's on (should be one at a time) and no change on the input by pressing the band selector. Also there was no activity on the display for the source locking.

I suspect the usual bad contacts (it's slot based construction) or power supply, more to the power supply side since the equipment hadn't been moved (it's a bit sensitive on moving/vibrations and that had been the cause of the first repair).

 First thing I did was removing and inserting all the boards one by one trying to find the one responsible for the selector LED's, I have the manual but didn't feel like to read it. In the end, had no luck. Then I realized there's another board that does not slide, instead is attached to the side panel. So I moved that one to the side and checked all the connections. 

 Image, now, after connecting back, started working, I can now select the input and have the digits lit:

I can measure again but I'm preparing a home made counter in case this one fails again in the future.

Have a nice day!