Hello, I'm trying to repair a 4500 Type 2961 receiver/amplifier for a good friend. Error behaviour is that power relais for the amplifier power (+/-33V) switches off almost immediately after switching on which points to a Power-Fail or overheat condition (NTC). It also happens when no speakers an no other devices are connected. When I switch on 20 times or so in a row, it usually switches on and works normally for several hours. After several hours of operation I powered down the unit over night but left it connected to the mains (rightmost LED on). And in the morning it switched on with the first try. Then I disconnected the mains for 1 hour and see the error behaviour again (relais switches off). I should probably mention that for some time I have seen the unit "half-operable": Radio part, amplifier abd remote control were working, but volume/sound control buttons did not work and also switching of sources did not work (only radio worked). That could have been a 8155 issue. Anyone has ideas what it can be or what I can try ? I would really like to helo my friend, since she likes the system so much. So any help is highly appreciated. Thanks in advance Pirmin