The two traces do not apear, and the voltages power supply are no good(for BM566A).
The"+12V" and "-12V" are "+11.4V" and "-3.55V" for BM 566A.I think there are broken some tantalium condensator.
There are many tantalium condensators and the acces to measure them is difficult.
IO3 the MMA741 is responsible to pull down and regulate the -12v rail...
Firstly, confirm the collector of E24 is at least -15v with respect to Ground;
Then measure pin 6, if it is at Zero voltage with respect to GROUND?
if it is, then the problem is the transistor E71 or E24 or both, otherwise replace MMA741.
Measure across R81/R82, what is the voltage?
Adjust R70 to attain +12Vdc, the negative -12v should tracks the positive voltage.