[morzh]

Andy


1. Measure the voltages across all tubes, compare with the Voltage chart. Report it here. Pay most attention not to some discrepancies but to drastic ones. Like voltages on plates being 0V or close instead of say 100+ Volts like they should be.

2. In case most turn out OK,
What you should do first is to try to do the "grid cap touch" test.
You have to be VERY careful as I understand you are not well familiarized with things yet.

You can use a screwdriver with an insulated handle for that. Most of us use our hands but for you I'd recommend starting with the screwdriver.

Unfortunately In your case there are no grid caps so it makes it a bit more challenging.

Start touching with the screwdriver the grids of the tubes going away from the audio like the G1 in this tube.

http://www.radiomuseum.org/tubes/tube_7v7.html

Listen if the buzz is there when you touch.
See when it stops.

then start checking the continuity of the interstage RF transformers after the tube where it stopped.

3. Overall continuity check on all inductances (RF transformers mostly what they are) should be done.