As a total DELL-Lover I only have such Machines around.
I just wanted to build up a OP 760 for my little son.
When I plug the power cort, the diagnostic LEDs 2 3 4 keep flashing while the power LED is amber.
System has only orgiginal DELL components, no add-on cards.
I checked out two CPU types:
intel E8600 and E7300
Also, I tried without any CPU - then, the diagnostic lights for a missing CPU light up.
I would be so perfect if there would be any solution for this.
Anyone knows how to fix that?
I would take a look at the Service Manual here (page 162) and from the desription it sounds like it could be a board/bios issue, but you could try unplugging the system, holding the power button down, and then removing the CMOS battery to see if it resets (then reseat the battery, plug the system in, and power on), but if not, unless the system is displaying an error on the screen it might be another hardware issue. Like you mentioned you could also try doing a minimal boot (nothing attached but memory and cpu), just to see if the status changes.
I hope you can get it started.
I did a BIOS Reset and the error code changed to
1-2-4 and amber Power LED
This error code is not described in the manual.
Sadly, it looks like this machine is dead.
Thanks for the update, I would try reseating the Processor, I was able to find a diag code stating that it means "Reinstall the CPU and restart the system. If the computer still fails to boot, inspect the CPU socket for damage. " Unfortunately if this doesn't work it could be CPU/ the socket itself/the board etc. But before throwing in the towel, perhaps a reseat of the CPU with everything unplugged from the board (drives etc) and just memory, board, processor, monitor and then boot the system just to see what happens.
If you still don't have any luck and the code hasn't changed then there unfortunately is a good chance that the hardware is faulty.
Let me know if you have any further updates.
Yesterday evening, I dissasembled the whole machine. I wanted to use the good things as spare parts. I also dismounted the CMOS Battery.
Your post made me to just plug the board itself on my bench, and then adding further components step by step. Also, I used another CPU than before (now an intel Core 2 Duo E8400).
Crazy: The machine started to live again!
Funny to see woh the status LEDs changend by every step.
BIOS is now revision A00
Also, the onboard graphic seems not to work. May God know why. So i used a PCIe Card.
Only sad thing: I always want to know the reason why. Why did this happen, what was the error, and so on.
Here, I have no idea.
So, I will reassemble the computer on saturday.