Dell optiplex gx520 wont turn on

SOURCE: Dell optiplex won't Boot-up.. Orange light on motherboard

its going to rather your power supply or your motherboard has died, id try a different power supply first

SOURCE: Orange light on Dell GX270 power button

I agree, the Optiplex GX270 is infamous for MoBos going bad. The capacitors have a manufacturing flaw, and up until February of 2008, Dell was replacing those boards for customers for free if it was found that the capacitors were the culprit. I just found a board yesterday with this problem. A sign that the capacitors are bad is either a buldge or they will be leaking an orange-rusted looking substance (primarily capacitors near the CPU). Symptoms of this problem include the PC rebooting itself randomly, and/or getting a BIOS error saying there was a thermal event.

SOURCE: Computer monitor stuck in safe mode

the problem is with ur Computer's Graphic card.

u can put a new one in case if it is a built in graphic card Chipset.

check ur manufacturer support page for more details.

plz rate this post as good as u can

SOURCE: the power light comes on as orange

REMOVE board from cabinet then check you can easily track the problem

SOURCE: Dell OptiPlex GX520 PC Desktop Problem

Hello everyone, check your cpu - I've just had one of these in for repair and the cpu was faulty - removing the ATX 4way 12v lead let the pc start rather then detecting a short and shutting the psu down. Changing the cpu cured the fault.

Thanks