Datron / wavetek 4808 15 V guard fail

[Patest]

I experienced this problem with my Datron 4808 and my wavetek 4808 all within one month, the main line voltage was from two different sources, one in my lab, the other at a customer site.
Are they worth fixing?

[ManateeMafia]

15v rails like to die from shorted tantalum capacitors. I have seen this a few times now on 4808, 4800, and 4700.

Some may argue that you should only replace the dead ones but so far I replaced all on each rail that failed. One calibrator had a domino effect where replacing one capacitor caused the next dead one to smoke. After a few iterations, I just bulk replaced them.

Also, the inguard PS can also be damaged. I would inspect it for any burnt parts. It is also possible that an inductor or two has failed. These are yellow and tend to become crispy after a short. . Inspect all boards that can be removed.

I also increased the voltage rating on the tantalums from 25v to 35v.