Safgan (DT-520) Oscilloscope

[Bobsy]

bobsy.

Have you blown yourself up yet?

Alan

Just a little singed! lol - Motivated me into buying a fluke ! I think I solved my problem that's why I'm returning to share
No schematics for my DT-520 however I spotted this schematic for the DT-410 (see attachment) which has given me all the clues I need.
It seems the Diode is a 'Zener 75v' straddling the intensity Pot (limiting the max voltage across the pot), which means the Cap (rated 250v on my DT-520) is pretty safe & connects to 'Centre' post on Pot! The cap looks like it is limiting noise on the output.
I'm just awaiting delivery of the Zener & am very hopeful at this point.
I'm glad I never gave up on this - When you grab a Tiger by the Tail its sometimes best not to let go!