Monitor Troubleshooting

[Rocky]

I'm trying to fix an oddball monitor. It's a Magnavox 8CM515 (I originally used in on a Color Computer 3 in the late 80's).

It is standard resolution and has an input with the standard pinouts for an arcade board (RGB, Gnd, Snyc). It also does composite and has input for CGA for a PC.

I was thinking of using it for a test station or a small cocktail. However, it died recently.

Using Randy Fromm's troubleshooting guides I believe it is a problem with the power unit. Here are the symptoms.

- No rastor or static on the screen
- No neck glow
- Whining noise coming from somewhere (I can't tell, but it doesn't seem to be the flyback. The pitch lowers and fades when the power is cut off.
- 5vdc across the filter capacitor
- No Led light on the power button.

I'm thinking it's either the High Voltage regulator transistor or the filter capacitor.