Power problems?

[X-13]

This is a bit of a strange one... One of our classroom computers is having intermitten power problems.

 

Sometimes it won't boot, sometimes it will.

 

I was just in there looking at why it was on but still had a black screen [power button on the screen was flashing. Signal, but no image.]

 

 

I turned the computer off, then it refused to switch back on. This isn't the first time it's happened.

 

 

I took it away to have a proper look at it, and it seems it takes around 5 minutes or so for the computer to charge up...

 

This is the only way I can think to explain it.

 

 

The motherboard light starts off dim, then gets stronger. When the power button is pressed, the light dims further until a certain point, where it stays stable.

 

After a few mintues, the fans will kick in when the power button is pressed, but it'll die. Then turn on without having anything touched.

 

 

TBH, I'm thinking this is a PSU problem. Or the start of one at least.

 

Any ideas?

[Kenny_G]

We once had room full of shuttle computers which did this but we never got to the bottom of the problem.

 

Possibly a Power Supply issue.

[X-13]

Cheers, Kenny G. [You're not a jazz saxophonist, are you?]

[penfold]

Viglen? - We had almost the very same thing happen and it seemed to be a dodgy PSU with a batch. Replacing the power seemed to sort the problem.

[X-13]

Viglen? - We had almost the very same thing happen and it seemed to be a dodgy PSU with a batch. Replacing the power seemed to sort the problem.

 

RM.

 

And they're JUST out of warrenty. Usually, I'd just drop RM a call and they'd send someone out...

 

 

Also, this is the... 3rd [4th?] with EXACTLY the same problem. All over the school, all computers bought at DIFFERENT times.

 

All used to varying degrees. [some hardly used, some used to excess.]

[Michael]

Sounds like a cold boot or PSU problem to me. Replacing the PSU should be fairly straight forward, but failing that, it could well be the motherboard on its way out.

[X-13]

Sounds like a cold boot or PSU problem to me. Replacing the PSU should be fairly straight forward, but failing that, it could well be the motherboard on its way out.

 

ah, [censored]

 

Seeing as the older ones that have died are about 5 years old, I think I'm going to have to suggest replacing them instead of repairing.

[rich_tech]

I had a similar problem a while back with my old Antec Trupower PSU in my home machine, the voltage wouldnt get high enough at times to allow it to boot up the machine, one of the rails in the device would hover about 10v and I had to repeatedly power it off and on on the PSU switch until it got a high enough voltage to start up, I replaced it a while later.

 

What I would recommend is getting a power supply tester, I got mine cheap off ebay, its worth the world with problems like this, as you can diagnose problems quickly and easily.

 

I have one like this - PC LCD 20/24 Pin PSU SATA HD ATX BTX ITX Power Supply Tester Test Power Voltage | eBay - I would get one that shows voltage levels on it over the other type with just LEDs, its a bit more informative as to what is going on with the PSU

Edited March 26, 2012 by rich_tech

[X-13]

Thanks, Rich.

 

I was looking into getting one before all this started anyway. At least I have a good reason now.

[PotNoodleTech]

Pop the lid and see if the motherboard has any capactors that are either leaking or have bulged tops:

 

Leaking:

http://www.thenakedpc.com/dan/Bulging_Capacitors/close-up.jpg

 

Bulged:

http://cdn.overclock.net/7/7b/7bd16ed4_bulging_capacitors.jpeg

 

China seriously screwed up millions of caps about 6-7 years ago and many manufacturers ended up having PCs/motherboards fail because of it.

 

We had 65 PCs die within 2 years (when they were 4 years old).

 

If it's not the above then it probably is the power supply as suggested by other good people above

[X-13]

@AButters That was the second thing I did.

 

The first was check the power cable worked.

[jedmondson]

I had a similar problem a while back with my old Antec Trupower PSU in my home machine, the voltage wouldnt get high enough at times to allow it to boot up the machine, one of the rails in the device would hover about 10v and I had to repeatedly power it off and on on the PSU switch until it got a high enough voltage to start up, I replaced it a while later.

 

What I would recommend is getting a power supply tester, I got mine cheap off ebay, its worth the world with problems like this, as you can diagnose problems quickly and easily.

 

I have one like this - PC LCD 20/24 Pin PSU SATA HD ATX BTX ITX Power Supply Tester Test Power Voltage | eBay - I would get one that shows voltage levels on it over the other type with just LEDs, its a bit more informative as to what is going on with the PSU

 

Just brought one myself as I have had 2 computers come to me with dodgy power supply.