# Compaq C500 Power Light Flashing



## caseycoughlin (Dec 4, 2010)

Hey, I just recently changed the DC power jack as well as the charger. Now when I try to power it up, it starts to power up and goes through as it should and about a minute into it, the computer shuts off and the power button light flashes until I pull the battery and charger out. It has gotten passed the login screen before so I'm pretty sure it's not the motherboard or anything. Please help!


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## GZ (Jan 31, 2010)

Hello caseycoughlin and welcome to TSF!

Take the battery out and attempt to start the computer up on the charger alone.


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## caseycoughlin (Dec 4, 2010)

Thank you. I just tried to start it with the battery out and it didn't start. It just went straight into the light flashing. But when I put the battery back in and started it, I made it to the password verification and the subsequent welcome screen and then shut off and the power light started flashing.

If it matters, the light on the power button and the LED power icon on the edge of the laptop flashes continuously with no pattern. No other lights flash.


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## caseycoughlin (Dec 4, 2010)

Any ideas at all? I'm stumped. Everything I've read says the motherboard is fried but I can still get to the "Welcome" screen and sometimes beyond.


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## GZ (Jan 31, 2010)

Hello again,

I am sorry, I must have lost track of your thread. 

When the power is off and the power adapter is plugged in, does the charge light come on?


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## caseycoughlin (Dec 4, 2010)

Yea, when it's plugged in, the charging indicator comes on and stays solid like it's charging normally.


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## GZ (Jan 31, 2010)

What happens when the laptop is run on the battery alone?


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## technobizzmo (Dec 9, 2010)

Well you say that you just recently changed the DC power jack as well as the charger. Can I ask(maybe a stupid question on my part) but why did you change these? Was there some kind of problem with the old ones?


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## caseycoughlin (Dec 4, 2010)

gavinzach said:


> What happens when the laptop is run on the battery alone?


I'm not sure. I don't think I've tested this yet and the laptop has been unplugged for about a week. So I think the battery may be dead? But my guess is that it won't turn on at all because the battery on a laptop should hold a charge on a laptop that is turned off. But I have it plugged in now. So I'll know for sure in a few hours.



technobizzmo said:


> Well you say that you just recently changed the DC power jack as well as the charger. Can I ask(maybe a stupid question on my part) but why did you change these? Was there some kind of problem with the old ones?


The DC jack was having the problem where I would have to constantly move the charger around for it to charge the battery. And since I found the charger for so cheap, I figure I might as well change that just in case it was a part of the problem. So I resoldered the new DC jack in and just use the new charger because, well, it's new. And by the way, in diagnostic, no questions are stupid, lol.


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## GZ (Jan 31, 2010)

If you still have the old a/c adapter, give it a whirl and see what happens.


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## caseycoughlin (Dec 4, 2010)

Yup, just as I suspected. I charged it overnight with the new charger and when I unplugged it and tried to turn it on, I got no response. Then after I put it on the old charger until a few minutes ago and I got the same result. No lights, nothing.


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## GZ (Jan 31, 2010)

Did you solder the DC jack yourself or did someone else do it for you?


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## caseycoughlin (Dec 4, 2010)

I did the solder work myself.


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## sj-elektronik (Apr 2, 2011)

I have s solution for power light flashing. The motherboard replace P-Channel Power Mosfet. Mark on the PQ49 Motherboard. Mosfet is the AO4407. Part tested:luxhello::luxhello::luxhello:


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