David Belles is still in business and is relatively close to you. He should be able to give you some advice. I don’t know if he tests and repairs, but he should be able to recommend a technician. I suggest calling him. In my experience, his email correspondence is not so great. He will reply with quick short answers, but if you talk to him on the phone, he is much more engaging and helpful. Call him on a weekday morning and he will answer.
Power Modules
479 East Street
Pittsford, New York
https://powermodules.com/contact-us