A3000D - Nothing coming out of the VGA port

Hello,
I have a very weird problem with one of my A3000 MoBo.

Everything works fine with it except for the VGA port. Nothing comes out of it.

The very first thing I tried was the switch and I know the 31KHz mode is obtained by setting it to the down position so this one is ruled out.

I even tried changing the flicker fixer's PLCC (Amber). I tried it on another MoBo and guess what? It works just fine!

I remember reading somewhere somebody mentioned a possible problem with fuses for that sort of problem but I wouldn't know where or what to look for.

I have a good multimeter to check for continuity without risking damage to the board so if anybody could tell me what else to try or where to look for these fuses, it would be highly appreciated.

Thank you all.

[banzai]

I remember reading somewhere somebody mentioned a possible problem with fuses for that sort of problem but I wouldn't know where or what to look for.

I don't have an A3K, but I did work on one once... Once.

According to my schematics, you'll want to look at the video hybrid "HY480". Specifically, fuse "F548" (if I'm reading it right) feeding the two Vcc inputs to HY480 and filtered by caps C492 and C493. This feed also has an EMI495 as an extra filter.

I'm guessing this will be either a "pico" fuse or SMT type. The pico style looks like a small resistor, usually a medium tan or light brown in color, with no stripes. The SMT will look like a small chip with a partition through the center (-ish). It can be brown, black, tan, yellow, or white, depending on what the designer's girlfriend decided looked best on the production line.

banzai

banzai wrote:
According to my schematics, you'll want to look at the video hybrid "HY480". Specifically, fuse "F548" (if I'm reading it right) feeding the two Vcc inputs to HY480 and filtered by caps C492 and C493. This feed also has an EMI495 as an extra filter.

Thanks! This sure seems to point in the right direction.

It can be brown, black, tan, yellow, or white, depending on what the designer's girlfriend decided looked best on the production line.

 :lol:  :lol: