Xc-540 display not working

[bvaleri]

I bought a used machine with the screen not functioning. It powers on and goes through warm up motion etc. but only the power light is lit up nothing else on the display. The leds are all lit green on the main/servo/head boards.

I tested all the components on the main board thinking it would be a fuse on there but everything seems to be fine. I also pulled the ribbon cable from the display board to the main and verified continuity between both ends no issues.

I inspected the panel board and I believe I am missing fuses on R106 and R109. I cannot see any reason those two wouldn't have a fuse aside from the wiring diagram saying 180(NON) on those compared to 180 on others. I have never seen that on a diagram before so was wondering if anyone could verify fuses should be in those locations.

If you have any other ideas why the screen may not be displaying feel free to comment, as of now I am planning to replace the panel board first and hope that fixes the issue.

 

[bvaleri]

I bought a used machine with the screen not functioning. It powers on and goes through warm up motion etc. but only the power light is lit up nothing else on the display. The leds are all lit green on the main/servo/head boards.

I tested all the components on the main board thinking it would be a fuse on there but everything seems to be fine. I also pulled the ribbon cable from the display board to the main and verified continuity between both ends no issues.

I inspected the panel board and I believe I am missing fuses on R106 and R109. I cannot see any reason those two wouldn't have a fuse aside from the wiring diagram saying 180(NON) on those compared to 180 on others. I have never seen that on a diagram before so was wondering if anyone could verify fuses should be in those locations.

If you have any other ideas why the screen may not be displaying feel free to comment, as of now I am planning to replace the panel board first and hope that fixes the issue.

I just found a clear enough photo to confirm there are not fuses in those spots, back to troubleshooting.

 

[bvaleri]

I injected power to the panel board and everything worked fine there, so it seems I do have a main board problem.

 

[bvaleri]

Though nobody has replied yet I am still looking for help.

I sent main board to premier color for repair, they sent it back and said there is no issue.

Tried a new ribbon cable and still no luck. The display panel is getting power to light up the led and power button but not the lcd screen. It shows no voltage at the screen when I test.

Bought a new display panel board and hooked it up today and that one has the same issue as well. I'm not sure what could be the issue unless the repair tech missed something on the main board.

Any advice or tips would be appreciated.