Anritsu MS2602a Spectrum analyzer repair help

[lectrohamlincoln]

Hi,

I just picked up a Anritsu MS2602a 8.5Ghz spectrum analyzer for free! However, it does not display any signal and it appears the A/D board has gone bad.

I suspect the A/D board for two reasons: the flow chart in the service manual vol 1, and when I took it apart the A/D board had a piece of masking tape with a big black X on it

The service vol 1. doesn't offer much in the way of diagnosing circuit level problems and it appears the service manual vol 2 is IMPOSSIBLE to find. I've done some rudimentary test, such as checking all voltage at labeled rails (all voltages good so far), and now I'm at a loss as to how to proceed.

Do you guys have any suggestion on what I should check next? Or where I might find the Service Manual vol. 2, a replacement A/D board, or even an extender so I can take the board out while the MS2602a is powered on?

[_Wim_]

I was facing a slightly comparable problem when repairing an SMU from Yokogawa (also no usable service manual). I got some excellent tips that are generally applicable in repairing a unit without knowing the circuit diagram:

https://www.eevblog.com/forum/testgear/yokogawa-gs610-source-measure-unit-service-manual-needed/

Hopefully your problem is also something simple, but off course, an 8.5Ghz spectrum analyzer is way more complex then my SMU...

Good luck, hope you find it.