Kenwood TS-820s almost dead

Question

My neighbor was going to throw away a Kenwood 820s-
but ofcourse i managed to resque it.
Its a beutiful rig-but it has a problem- the only things working is the fan and the-s-meter light.
I have checked all the solderings, contacts,plugs over and over. Nothing burnt as far as I can see.
I only have a simple volt-tester.
Any ideas on where to start ?
73/Stig in a cold and snowy Stockholm