Marc wrote:
Dear Sir,

Thank you for your response. I have been studying the schematics and I
am familiar with the placement of the components on the F-2625 power
supply board and the F-2624 driver board.

My troubleshooting skills are minimal. I was going to check the listed
voltages at various points on the power supply and driver boards i.e.,
output from driver board, voltage across power transisters.

I can check individual components. I am just not sure if you can check
them on the board or if they should be removed and then tested.

I have not noticed any parts that look burnt.

Age and heat probably led to the failure. I stored the equipment in a
stereo cabinet but it did not have proper ventilation.



Probably you are going to need to bring it up on a current limited
bench supply, depening on how many different voltage supplies there are
in the box. The solid state power amps that have a plus and minus rail
are easiest. These things aren't made for easy servicing, making it
tough to unhook unneeded subsystems for test in many cases.

The caps should be tested separately if they can be isolated without
unsoldering from a board. If they come up to rated voltage and hold it,
they should be checked to hold the charge for a long time. Sometimes
bringing them up, letting them sit, and sudden discharge (use wires so
as not to arc the terminals) does them good-or kills them.

There's a case for changing every lytic on the box if it is old enough
to be President.