Third Beomaster 8000 - First Life Signs

This is turning into a fully blown addiction. I bought a third Beomaster 8000!!! Of course broken...gotta have some fun! Today, I finally opened it up with the plan to bring it on line slowly. I disconnected the 45V power supply from the output stages (pulled red and black cables on L and R output boards). The purpose was to avoid a potential burnout of the output transistors in case the trimmers have contact problems. After disconnecting, I checked the main capacitors on board 6 (power supply) to see if they still work. They showed reasonable values. Then I connected the Beomaster to the mains. Without pressing a button, it immediately showed some random segments on the displays:

No response to any buttons. This made me think and pull out the circuit schematics. After some study I came to the conclusion that it is time to check the voltages relevant for the microcontroller and the displays. I measured on P48 on board 6 that the pins that should carry 5V only measured 2V. This means that the microcontroller is starved below its minimum voltage of about 2.7V. The circuit diagram shows that these pins are directly connected to the output of the 5V voltage regulator. That left practically only one possibility (aside from an (unlikely) short somewhere on the microcontroller board): C35 must be bad. Indeed a measurement with my capacitance meter indicated a capacitance of 2.3 nF instead of 10 uF. I immediately replaced the capacitor with a new one. Plugged the Beomaster back in and it started up normally. After pressing a button I got this:

As usual, several segments are dead and these displays need to be refurbished. A worrisome phenomenon: No response to turning the volume encoder...well, it would be boring if they always had the same problems. More about this in the near future.