by Klaas Robers » Sat Apr 11, 2009 8:33 pm
This is a tube voltmeter (right) and an oscilloscope in one.
Please first make a list of the tubes and the position where they are now.
Then remove the rectifier tubes (the two large ones next to the power transformer) and first test the primary and the filament circuits. Then the tubes should glow.
If they don't there are only a few causes possible:
1. No mains voltage, power cord broken, plug not making contact, measure where the power cord enters the chassis (right back)
2. Fuse in the mains circuit blown (this always has a deeper reason) (I haven't seen one yet in your nice photos.)
3. Mains switch not working.
4. Transformer burnt out (you can smell this).
So: measure the voltage going to the transformer, if present:
measure the voltages coming out of the transformer. The twisted yellow and black wires are the filament voltage, going to all small tubes, should be 6,3 volt AC.