Hi all. Just purchased a 7d20, and powered it up in my 7854.
It was sold as working, which it mostly does…..but sadly self-test fails with attenuators codes. I looked here for previous posts and noted several mentioning cleaning contacts. And (maybe) PWB pads.
1) has anyone tried the “wash in (Kelite) method per Tek publications on plugins, as opposed to full scope chassis? I remember reading wizard Analog designer Bob Pease mentioning washing PWBs in a dishwasher.
2) Has anyone tried cleaners such as DeOxit on relay contacts, and similar contacting surfaces?
I’d like to be able to clear the self-test errors with a minimum of disassembly, as my “workspace” is a makeshift temporary one, so projects must be very short term. Someday,I’ll work out a real test bench.
One note which might help with relay contacts: I remember reading about a non-abrasive method of cleaning fragile contacting surface using a strip of typing paper wetted with IPA. As I dampened paper was inserted between the open contacts, then they were closed, and the paper pulled through for cleaning.
If I remember correctly, it was for some relays in HP gear…..maybe attenuators relays in a 3325 function generator (I actually happen to have one with bad attenuators relays, but have not diagnosed the root cause).
I’d appreciate any wisdom on cleaning methods, esp w/r/t 7d20’s.