Hellpp!! I'm trying to resurrect a DOA Kenwood M2A and I'm stuck. I've replaced most of the parts (yes you read that right) so I'm not sure what's causing the problem. In a nutshell the problem is that I have around 40V where signal ground should be. This is almost full rail voltage since I'm using a 60 watt bulb in series which cuts most of the voltages about in half. (I have the same problem at full voltage, but I don't use full voltage very often to avoid blowing something.) The main relays don't close, and neither does the signal relay near the input. At full power the blinking protection indicator lights up. The schematic is below along with screen shots showing my measured voltages in green. Where there is no green voltage shown the measurements are pretty close to spec (mostly where controlled by a zener). The problem seems to be almost perfectly symmetrical, i.e. the same in both channels. Does anyone have enough experience with these to point me in the right direction?
The whole schematic was too big to attach so you can see it here.
The whole schematic was too big to attach so you can see it here.
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