Will bad caps cause a power supply failure?

chadz28 · 07-26-2007, 02:38 PM

Hello, everyone. My brother has a Gateway computer that was rebooting itself, until it finally wouldn't power up. I replaced the power supply and all was fine for a few days. He said it beeped 3 times and then lost all power again. I didn't want to waist another power supply, so I pulled the board to look for burn spots and didn't find any, however I did find 2 caps with brown stuff on them. My question is, did those caps with the brown stuff cause the second power supply to go bad also or is it possible that the second power supply caused the caps to blow? I am a rookie so any information will be appreciated. Thanks and sorry to bother you guys.

Sparky · 07-26-2007, 03:03 PM

The old PSU could have caused the caps on the mobo to start to fail, then later totally went out. You can test the current PSU by shorting the green wire and a black wire on the 20pin connector to power it up, then use a DMM to test the voltages and such.

Harvey · 07-26-2007, 04:44 PM

Don't power up a PC PSU without a load - some of them don't like it and fail, sometimes in a spectacular way, if ran for more than a few seconds.

Stick an old hard drive or CDROM or something on at least to give it something to run.

I'd be inclined to say the motherboards caps are on the way out - changing the PSU probably just gave them the extra bit of 'ooomhp' to run for a short while. Have you tested the old PSU at all?

chadz28 · 07-26-2007, 08:22 PM

Thankyou Harvey and Sparky for getting back with me so soon. Yes I did test the old PSU with a multimeter and got no voltage readings, I also tested with a wire to the green and black pin and it would not supply power to a cd-rom. I just looked for burn marks on the motherboard. When I didn't find any I thought it was just a PSU failure. So I installed the second power supply and it went bad a few days later. Until finding your forumn I didn't know about the possibility of caps going bad. Thats when I found two caps on motherboard that had brown stuff on top of them. After I removed the second power supply, I heard something rattleing inside so I took it apart and found 2 small caps inside just laying there inside the PSU that evidently were blown off and I saw some burn marks where it look like they once was located. The first PSU was bad. I just hope the second used PSU that I installed didn't cause the caps to go bad. I am hopeful that the caps were the reason the second PSU went bad. Also do you think other componets are salvageable? Again thanks for teaching me, I am greatful and love learning.

Sparky · 07-26-2007, 08:48 PM

Do you have another known good working PSU you can use? Just to hook up to the PC real quick to see if it powers on. If it does, then I would recap the mobo and you should be good to go afterwards. Talk to Topcat about replacement caps as he can supply you with what you need.

Glad to be of service

yanz · 08-06-2007, 09:46 PM

probably the second psu was also almost near its end of life before you placed it in this system. i dont think it was the motherboard that makes the second psu went bad. it will more make sense if the psu that makes the mobo bad. cmiiw..

because the motherboard was powered with bad psus, i worry if it is still okay.. moreover it already has bad caps. as sparky suggestion, try with good psu next time. if it lives up, do a recapping then..

07-26-2007, 02:38 PM	#1
chadz28 New Member Join Date: Jul 2007 Posts: 2	Will bad caps cause a power supply failure? Hello, everyone. My brother has a Gateway computer that was rebooting itself, until it finally wouldn't power up. I replaced the power supply and all was fine for a few days. He said it beeped 3 times and then lost all power again. I didn't want to waist another power supply, so I pulled the board to look for burn spots and didn't find any, however I did find 2 caps with brown stuff on them. My question is, did those caps with the brown stuff cause the second power supply to go bad also or is it possible that the second power supply caused the caps to blow? I am a rookie so any information will be appreciated. Thanks and sorry to bother you guys.

07-26-2007, 03:03 PM	#2
Sparky High voltage Join Date: Jan 2007 City & State: Ohio My Country: USA Line Voltage: 120VAC 60Hz I'm a: Hobbyist Tech Posts: 224	Re: Will bad caps cause a power supply failure? The old PSU could have caused the caps on the mobo to start to fail, then later totally went out. You can test the current PSU by shorting the green wire and a black wire on the 20pin connector to power it up, then use a DMM to test the voltages and such. __________________

07-26-2007, 04:44 PM	#3
Harvey Badcaps Veteran Join Date: Apr 2007 Posts: 232	Re: Will bad caps cause a power supply failure? Don't power up a PC PSU without a load - some of them don't like it and fail, sometimes in a spectacular way, if ran for more than a few seconds. Stick an old hard drive or CDROM or something on at least to give it something to run. I'd be inclined to say the motherboards caps are on the way out - changing the PSU probably just gave them the extra bit of 'ooomhp' to run for a short while. Have you tested the old PSU at all?

07-26-2007, 08:22 PM	#4
chadz28 New Member Join Date: Jul 2007 Posts: 2	Re: Will bad caps cause a power supply failure? Thankyou Harvey and Sparky for getting back with me so soon. Yes I did test the old PSU with a multimeter and got no voltage readings, I also tested with a wire to the green and black pin and it would not supply power to a cd-rom. I just looked for burn marks on the motherboard. When I didn't find any I thought it was just a PSU failure. So I installed the second power supply and it went bad a few days later. Until finding your forumn I didn't know about the possibility of caps going bad. Thats when I found two caps on motherboard that had brown stuff on top of them. After I removed the second power supply, I heard something rattleing inside so I took it apart and found 2 small caps inside just laying there inside the PSU that evidently were blown off and I saw some burn marks where it look like they once was located. The first PSU was bad. I just hope the second used PSU that I installed didn't cause the caps to go bad. I am hopeful that the caps were the reason the second PSU went bad. Also do you think other componets are salvageable? Again thanks for teaching me, I am greatful and love learning.

07-26-2007, 08:48 PM	#5
Sparky High voltage Join Date: Jan 2007 City & State: Ohio My Country: USA Line Voltage: 120VAC 60Hz I'm a: Hobbyist Tech Posts: 224	Re: Will bad caps cause a power supply failure? Do you have another known good working PSU you can use? Just to hook up to the PC real quick to see if it powers on. If it does, then I would recap the mobo and you should be good to go afterwards. Talk to Topcat about replacement caps as he can supply you with what you need. Glad to be of service

08-06-2007, 09:46 PM	#6
yanz Badcaps Veteran Join Date: Nov 2004 City & State: Dago, Bandung, Indonesia Posts: 833	Re: Will bad caps cause a power supply failure? probably the second psu was also almost near its end of life before you placed it in this system. i dont think it was the motherboard that makes the second psu went bad. it will more make sense if the psu that makes the mobo bad. cmiiw.. because the motherboard was powered with bad psus, i worry if it is still okay.. moreover it already has bad caps. as sparky suggestion, try with good psu next time. if it lives up, do a recapping then.. __________________ days are so short when you actually do something..

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