My optiplex will not start up. Light blinking

the led's are covered in the manual at dell.com
welcome to dell.
https://www.dell.com/support/home/us/en/04/product-support/product/optiplex-760/manuals


see your manuals, the service manual covers service.
page 162 in fact.

For the Optiplex 320, a flashing amber light with no sound indication can mean 3 things.

1) Your power supply has failed

2) Your motherboard failed, most likely from a bad capacitor.

3) The front panel board (where the power button is located) is faulty or not connected properly.

I've worked with 10's of 1000's of Dell Optiplex's over the past 8 years and the flashing amber light is well known as a tell-tail sign of one of those three failure. Always start your trouble shoot with a PSU tester, then inspect the motherboard for domed or split/leaking capacitors...then on to the front panel which would require another panel and ribbon from the same model.

Fans working? Maybe a PSU failure? Replace CMOS Battery. Reseat/replace Memory Mods. It's getting a bit old. Hard to say with a older computer thing start to go one by one. I replaced a PSU after 7 years. CMOS battery dead, replaced, Then the Sound Failed, new sound card. etc. I stripped it of useful parts and sent it out into the world.

DELL OPTIPLEX GX 620 PC WILL NOT START.
ONLY ORANGE LIGHT.

In addition to the power supply, motherboard issues can cause the blinking power light and no boot problems. The Optiplex 270, 520, 620, 745 and 755 units are all known to have issues with capacitors on the motherboard. Here is a link to an article about this issue and what to do about it:

http://www.ccl-la.com/blog/index.php/dell-optiplex-745-repair/

I hope this helps, if sol please rate my solution.

BuddyMc

Try to clean the RAM and place it again in the motherboard.

the fan is just fine dont wory about it and as long as you keep the battery charged you wont need to plug it in. (as long as its a labtop)

you may want to do a search on the dell website, i had that problem and never fixed it, you might find the information under service manuals search.
good luck.

You need a start-up CD and re-flash the Bios to Factory settings that worked. Best guess would be something was wrong with the BIOS package you had installed or someone/something messed up the installation which is causing your problem.

If you have factory CD Try to start the computer with that in.

Check your WGA and try another monitor in that pc