Commodore.ca: The PET, VIC, 128, 64 & More Forum

Hi, I'm having a problem with my machine's power supply. when you plug it in, the screen shows a green line that lasts 4 seconds and blows the fuse.

After that time, Every time plug in whether the fuse is on or off, the problem will happen. How should I handle it now? Thank!

Hi,

From the "green line" description I'm assuming that the machine is from the PET series.
In general the lack of vertical deflection and the blowing fuse suggests:
- failure in the 18V supply of the CRT unit
- shorted component(s) in the vertical drive circuitry of the CRT unit
- not running vertical oscillator (missing vertical drive signal e.g. due to CRTC chip failure or signal buffering failure, or bad contacts in the monitor signal connector)

Or any combination of the above.