If you are up to do it yourself with some guidance I have seen Dunsmore himself answer repair-related questions over at the EEVblog forum.

Thanks! That is a very active message board, I will peruse it. But I don't want to take on a project like this, it might end up in forgotten pieces as my attention span is pretty short these days. I wonder if Shariar at Signal Path (on Youtube) would do contract work or knows someone that does...

Steve

We repair the older HP 8510's or early generation PNA's.

i used Test Equipment Connection about 8 years ago for upgrades to an HP ANA. they are in Lake Mary, FL

Thanks! Someone should be getting in touch...