Iwatsu SS-8120 mainframe and A-880 spectrum analyzer service manuals wanted

[Mike P]

Hello,

I'm struggling to try and repair and old (1980's) Iwatsu spectrum analyzer which I bought recently on the dreaded eBay.

The unit I have is ex MOD (ministry of defence) and is a modular type design with a mainframe display unit and a spectrum analyzer plug-in.

The mainframe/display unit is an SS-8120 and the S.A. is an A-880.

I'm finding it impossible to to get hold of a copy of the service manual. I've emailed dozens of repair shops here in the UK, posted on several forums and I even tried emailing Iwatsu and Japanese!

Iwatsu kit is very rare in the UK and I'm hoping (praying) that someone in Australia or the U.S. might have a copy, or be able to help me with the repair.

One more thing; the mainframe of my SS-8120 looks visually very similar to that of the TS-8123, so a service manual for the TS-8123 might be helpful.

Many thanks, Mike

[Mike P]

Still looking.

Anyone got one?

[coppercone2]

No, but if you have all the parts you might be able to figure out what the problem is.

maybe we can give you a clue and it would make the thread more entertaining if you described the problem.

There is some good things to test like if the reference oscillator is working, if there is activity on certain digital circuits, etc. But my luck with SA repair is terrible, usually the main problem is even if you have a manual, the extension cards are a problem.

Start with the voltage rails, hopefully its a bad voltage rail so you can find the problem. If its a signal problem you need to go in deep. 

See if you can even make or get extension cables, because with out them, with modules, your gonna have a really really tough time. Insanely hard IMO. You can guess at a few things by attaching thin probes and reinserting but its like some 'fix my space ship to get back to my home planet' type of shit, twilight zone episode.

Every mainframe ever manual for service is going to have some kind of difficult to obtain cable or card extender, which you will likely need to figure out if you can make.