Don't use the hold mode when checking voltage. You need to ohm out the 3 transistors and see if any of them are shorted, in particular Q2. Unplug the 850 and put your meter on ohms and check between the collector and emitter, collector and base, emitter and base, and tell me what it reads in ohms. That will tell you if it is shorted.D2 cathode 66.5
D4 cathode 66.5
D1 anode -67.7
D3 anode -67.7