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Weirder than usual HP desktop problem – power supply - motherboard?

Alan Silverman
on
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Last Modified: 2013-12-11
HP Pavilion a6244n running Vista Home Premium with 3GB Ram 500 GB Hitachi hard drive, ASUS motherboard, nvidia graphics card and Intel core 2 duo processor.

On Friday a customer called me and said he’d been trying to get on the Internet for the past four days.  He has Time-Warner cable.  He replaced the modem but that didn’t help.  I went to his house and saw that he was getting a “network cable unplugged” message.  I put in a PCI ethernet card, disabled the onboard LAN and he was online.  

Sunday morning he called me up. He said that he worked an hour on Friday, then shut the computer down.  Sunday morning he started the computer back up and went out of the room.   When he came back he smelled smoke.  He immediately pulled out the power cord. After a bit he put the cord back in but the computer wouldn’t turn on.  

He brought the computer to me. I cloned the hard drive to protect his data, put the cloned drive in the tower and tried to start it. When I pushed the on/off button I’d get a light on the power supply, the fan would go on for a second and then it would stop.  I tried two other power supplies with no luck.

Before declaring the motherboard officially dead I took out the memory, tried to boot, and got nothing. Then I took out the ethernet card, modem card and the PCI-E nVidia graphics card.  I restarted the computer and the fans went on and there was beeping because there was no memory.
 
I put the memory back in and tried again.  The power supply went on and it started, but of course the graphics card and drives were not connected.  
I put the graphics card back in and the computer wouldn’t start.  
I put in a new graphics card and the computer started up.
I put in the PCI cards, connected the drives and everything started fine. So the graphics card had fried. I figured that was it.

I ran the computer for a while, then put in the old hard drive as a secondary and booted back up. I put the cover back on and started running programs.

Something wasn’t right. Sometimes it would freeze. I got a STOP d0000144 – Unknown Hard Error.  Then I got a BSOD stop 8E (0XC0000005 in iastor-sys.  A few reboots later I saw a puff of smoke.  I immediately pulled out the power cord.  

I thought the new graphics card would be fried but it was OK. I put in a new power supply, mainly because I couldn’t think of anything else to do. All today (Monday) I’ve been updating the computer without problems.  But it seems strange how this thing progressed.  The onboard LAN died but the computer was otherwise usable for several days.  I put in the ethernet card, the computer and Internet worked for an hour but the next time the customer turns it on the video card dies but the power supply keeps on working.  I would have much rather the old power supply stopped working completely. Could there be something wrong with the motherboard or maybe even the electrical system?

At around the time this began there were thunderstorms and they had a power outage.  But the customer says he thought the Internet problem itself began before the outage. He has a good surge protector and everything was surge protected except the coax cable going into the modem.  I’ve since made sure that goes through the surge protector too.

So if it was a surge coming through the coax, it came through the modem but didn’t destroy it, through the router, but that’s still working, both wired and wirelessly, then went out through the ethernet cable and killed the onboard LAN.  

It then damaged but did not destroy the power supply in such a way that the power supply eventually killed the graphics card and then, after the graphics card was replaced, caused the computer to freeze and other problems, and finally caused a puff of smoke, after which I replaced the power supply.

Does this scenario make sense?  I don’t like it when pieces of equipment die over time (first the LAN, then the graphics card) and others (the power supply) seem to be working OK but might be causing other things to fail.  Much better if the whole computer gives up the ghost.  Now it seems to be running fine, but I told the customer not to leave it on when he’s not around.  

Is there any way to test the electric and motherboard to see if it’s OK?

Thanks,
Al    
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