As promised... here are my findings on the +12Volt and -12Volt sections of the Data East Power Supply Board...
Below is a close-up pic of the +12 and -12 Volt sections (this includes the +5 Volt rectifier section):
1) Although the +12 Volt section doesn't cause many problems, it is closely tied to the +5 Volt section. This said, it is best to replace the 4 x 4700uF 25V Capacitors here. Replace them with 4700uF 35V capacitors (the voltage isn't that much of an issue, as long as they are of a higher voltage than original -
do not use higher uF capacitors!)
2) The -12 Volt section is only used for audio, so it is not essential to replace this capacitor. If you do, replace it with a 1000uF 35V cap.
3) Although the Bridge Rectifier may be OK, I recommend replacing it. This part does the most amount of work on the Power Supply, and will start to fail over time. Usually it will start to break down and cause intermittent faults, so best to replace it now. It supplies the rectified DC for the +5 Volts, +12 Volts and -12 Volts.
The next step is the +5 Volt section...
