Power light blinks [Archive]

jojo3

07-20-2009, 01:39 PM

Hello,
My friend's Compaq desktop needed more RAM, she doesn't understand anything about computers except surfing the web and e-mail so I said I would install the RAM for her. I open up the PC and of course it was full of dust so I used a can of compressed air and blew out the dust like I have done hundreds of times before, but when I hooked up the PC and started it up, it would not start but The power light would blink on and off .
I unplugged all the power and connector wires inside and replugged them,but the same thing still no power.

:eek: the power light still blinks even after I unplugged the cord??? :confused:
It blinks slower and less intense untill finally, after about 1 or 2 minutes it will stop.
What is going on and what did the blowing out the dust do to the PC.

Thanks in advance

JonGerow

07-20-2009, 01:57 PM

The light is probably "fading out" because it's a slow drain on the +5VSB filter caps. Same reason the LED on a laptop brick "fades out" when you unplug it from the wall.

As for the blinking light and no post: Is this before or after you installed the RAM? Or did you only blow out the dust with the canned air?

jojo3

07-20-2009, 02:35 PM

Thank you for the quick reply :cool:
This is after I replaced the RAM, but I reinstalled the old RAM and the same thing happened and I just tested both RAM sticks in other PCs and both work fine.

shadow_419

07-20-2009, 02:55 PM

Clear the cmos. The bios needs to be reset so you can load optimal defaults.

jojo3

07-20-2009, 03:36 PM

Clear the cmos. The bios needs to be reset so you can load optimal defaults.
The PC will not power on. The light blinks but no power.
The only thing I can think of is to remove the battery.
I gave it try and I still get the same problem.

shadow_419

07-20-2009, 04:14 PM

Clear cmos ( remove battery and switch jumper )
leave for 1 minute then reverse

Make sure psu is connected properly to the motherboard. 24 pin main atx and 4 pin +12v

Try to boot the computer with only cpu, 1 stick of ram, video card

jojo3

07-21-2009, 08:18 AM

jojo3

07-22-2009, 09:03 AM

I tried a different power supply and now the PC powers up the way it's supposed to.
How does compressed air damage a PSU?

shadow_419

07-22-2009, 10:31 AM

Condensation. The air is pretty cold and warm components especially caps that still have current stored could short.