help with my dell 4550-merged

[dmzof]

Hello, I am a first timer here, I need help with my Dell 4550 PC, my computer just quit working the other day, I can turn the computer on but nothing happens, nothing comes on the monitor. I already checked the monitor and it does work. The a,b,c,d light on back colors are: a green, b green, c green and d is yellow. I looked at one website and and it says other failure. I states to check that all cables are properly connected from the hard drive, CD drive, and DVD drive to the system board. I think I have check this. Any other ideas?

[dmzof]

I just wanted to know if anybody knows about a dell 4550. It quit working, the computer turns on but nothing on the screen, lights on back a,b and c are green but d is yellow.

[PrntRhd]

Merged, please wait 24 hours to bump a thread, don't start additional ones for the same issue, that only confuses the natives.

[Paul Komski]

If there is no beep at startup and a black screen then there is a failure to POST and that coupled with the diagnostic lights makes it look like a device failure.

If you can detach the cables from all drives (hard, optical, floppy) and then see if there is a beep and display you would need to add them back one at a time to find the culprit.

Any failed bit of hardware can cause a failure to POST so if detaching the drives doesnt help you should next remove all cards and any peripheral devices including keyboard and mouse to see if you can get anything to display.

The final step would be to remove the RAM because that should force the system to beep. After that it would be mobo or cpu or psu failure but they would likely produce more than just one yellow diagnostic light.

I left out video card failure which must also be a possibility. I don't think that model has on-board video to try as an option.