Dead PSU?

[killerasp]

Holy crap, today couldnt be a worser day for this thing to die.

i was formatting a friends computer and running windows install, when it would just suddenly shut down. I thought to myself, maybe she kicked it and the power cable was loose. But when i hit the power button, it wouldnt turn on. After a couple of mins, i turn it back on and continue windows reboot. It gets in about 15mins then turns off. Im like WTF??!? I look at the computer, figit with the cables and then i touch the outer part of the PSU and its BURNING HOT. IT burnt my fingertips when i touched it. Im thinking the fan died on the PSU and it overheated causing the PSU to die. Its a cheapo depo brand btw. What do think? Did it die? I dont ahve another PSU to switch it out and test it.

 

[DiZASTiX]

Holy crap, today couldnt be a worser day for this thing to die.

i was formatting a friends computer and running windows install, when it would just suddenly shut down. I thought to myself, maybe she kicked it and the power cable was loose. But when i hit the power button, it wouldnt turn on. After a couple of mins, i turn it back on and continue windows reboot. It gets in about 15mins then turns off. Im like WTF??!? I look at the computer, figit with the cables and then i touch the outer part of the PSU and its BURNING HOT. IT burnt my fingertips when i touched it. Im thinking the fan died on the PSU and it overheated causing the PSU to die. Its a cheapo depo brand btw. What do think? Did it die? I dont ahve another PSU to switch it out and test it.

sounds very much like a heat problem to me. The outer casing of the PSU should not be anywhere near hot enough to burn you. Look and see if the fan is running when it is on. If it isn't thats your clear problem and if the PSU isn't permenatley damaged yet you can replace the fan and it would work...

 

[killerasp]

sounds very much like a heat problem to me. The outer casing of the PSU should not be anywhere near hot enough to burn you. Look and see if the fan is running when it is on. If it isn't thats your clear problem and if the PSU isn't permenatley damaged yet you can replace the fan and it would work...

okay. it wont even turn on now. Would changing the fan make the PSU work again? if it did indeed burn out, that wouldnt make a difference

 

[DiZASTiX]

okay. it wont even turn on now. Would changing the fan make the PSU work again? if it did indeed burn out, that wouldnt make a difference

nope. If it burned out, it's dead now. If it wont even turn on at all then it is dead. Sorry

If you are good with electronics you might want to open up the psu and see if something can be replaced to fix it, but it can be dangerous, only open it up if you know what you are doing...

 

[Ice Czar]

I wouldnt recommend it, get a good PSU for that machine
replacing a fan is simple enough, but spend any time in here and youll see dozens of my PSU fried my mobo\RAM\HDD ect

especially since its a customers PSU, youve found the problem
now be a hero and fix it

I would not trust that PSU

 

[killerasp]

I wouldnt recommend it, get a good PSU for that machine
replacing a fan is simple enough, but spend any time in here and youll see dozens of my PSU fried my mobo\RAM\HDD ect

especially since its a customers PSU, youve found the problem
now be a hero and fix it

I would not trust that PSU

HELL NO am i opening it. im gonna kill myself if i do that. Im just gonna bring in another PSU tomorrow from home and test it. if indeed it is it, ill just make them by another one.

 

[Ice Czar]

by fix it I meant get a new one

besides unlike a monitor, a PSU doesnt hold much of a charge in the caps and they are easily drained, and in the event you where going to replace the fan, you would have to open it up

my basic formula for weighing the tradeoffs when buying a PSU

add up the rails with this calculator
http://takaman.jp/D/index.html?english
and compare it to the specs listed on the PSU
then you build in a safety margin of from 1\2 to 1\3rd
by deducting 1\2 to 1\3 the value of the PSU's rated amps and see if it still fits
it actually varies with the distribution ratios your likely to need more +12V than +3.3V or +5V
(CPUs now being powered by the +12V primarily)
possibly more if it a long term infrastructure investment and there is growth built in
of if the veracity of the manufacturer is in question (generics tend to lie like dogs)
most 250 or 300 watt PSUs will actually run most configs, but stability has become an increasing concern with the tighter tolerances onboard (FSB)

There is a decrease in total capacity with the rise in temperature , which reduces your amps, the rated amp values where taken at 25C
while your likely operating temperature will be 40C (especially if the PSU is in the top of the case exhausting the CPU HSF) and that is roughly a 30% decrease

That is offset by the additive nature of the calculator, employing all tha maximum draw figures for the assorted components, something that will never occur

However it gets even more complicated if you have alot of drives and fans, those are typically given a "run time" draw value in a calculator, there "spinup" draw can be 4 to 5 times as much and they greatly contribute to transient response overshoot and undershoot in some supplies at startup if there isnt enough +12V

The way you torture a power supply is to give it a fluctuating AC feed to deal with (from surge to brownout), at the same time you ask it to deal with a really dynamic internal load change (like spinning up alot of drives of having the CPU or GPU go from idle to full load) while still keeping the rails stable enough for the onboard voltage regulation components of unknown quality

 

[killerasp]

good news. went out and got a new PSU. everything is working fine. thanks.