Solve : No power after power cut?

1.	Solve : No power after power cut?
Answer» We had a power cut Sunday night while I was on the pc. I unplugged it straight AWAY hoping that would protect it . Power come back so I plugged it back in and turned it on but nothing happened, all I get is flickering light on the keyboard and mouse and nothing else. I'm thinking PSU but not certain. That sound likely? ... Cheers guysWell that would probably be the best place to start.However depending on the situation of the "power out" that could have a large bearing on what damage might have been done.For instance if it was due to a scheduled or even non scheduled loss of power in your area then the damage if any would tend to be less than if it was from a close by lightening strike.One causes power loss the other causes a surge or excess of power instantly. Both are not without possible negative affects on computers.truenorthCheers mate. I did ring a IT expert who said he doubts it's the PSU. He said he didn't think that was the problem due to the fact I'm getting flickering lights on mouse and keyboard. I know from past experience tho that isn't always correct. "that isn't always correct" your correct that isn't always true. The PSU provides a variety of voltages and via a variety of connectors so while the "expert" may have doubts i personally would want to verify that and eliminate it if possible and the easiest and quickest way is to install (even if only temporarily) a PSU of equal or greater capacity and OBSERVE the results.truenorthToggle the black power switch on the back of the PSU with the PC plug removed... Un plug it and reconnect to the PC and power back up...Just tried unplugging power chord and plugging it back in, still same OUTCOME. I think my PSU is buggered. I did notice a while back that it was starting to BOOT up slowly. I've read this could be a sign of a dieing PSU, maybe the power cut just finished it off? Did you do as i suggested ? ?Yea mate tried it, same outcome. You think that sounds like buggered PSU? Yepper... Another item that will cause these symptoms is if it's an older PC that has a modem card it tends to take the 1st hit...if it does remove all power to the PC...remove the card and re-boot. If the above does NOT apply borrow a known good PSU of the same or greater wattage amd swap it in there overnite to test... Best of Luck.Pc is around 4 years old mate, I just had a look and I didn't see a modem card. I was told it could also be my graphics cards. I tried disconnecting them as well but that didn't work. I'll try get hold of a second hand PSU and try that. cheers for the help pal Quote from: jay_1978 on June 05, 2012, 09:48:55 AM Cheers mate. I did ring a IT expert who said he doubts it's the PSU. He said he didn't think that was the problem due to the fact I'm getting flickering lights on mouse and keyboard. You would be right to doubt this, since it's just plain wrong! A faulty PSU can be the cause of nearly any observable symptom; whether certain lights flash or whether fans spin and so forth isn't indicative that the power supply is working properly, just that those devices are getting power. Sort of like when you have a brown-out, your incandescent light bulbs will still work, but a lot of other stuff might not. The various components in a machine have different tolerances as for how far from the norm they will work. It might be possible that the power supply is faulty in that it gives PWR_GOOD for a few seconds, then stops. If a machine does not RECEIVE PWR_GOOD, the CPU will sit in a reset loop. If this is the case than the PSU is actually working exactly as intended; parts of it's insides may have been hooped by a surge as the power cut or something to that effect. Good quality power supplies are designed to sacrifice themselves in that case. How a "sacrificed" power supply acts depends on how it was damaged. Not all power supplies just stop working; your's still seems to do something, but something kicks in afterward to stop it from powering up properly. It could also be the graphics card, too. Really the only way to find out what is wrong is to swap out various parts with known good components. The only way to really test that though would be to swap in a known-good power supply. Got some IT bloke coming tomorrow, he reckons it sounds like the PSU, plus the pc was starting to get slower which he said is a indication of a dying power supply. Thanks for all ya help

Answer»

We had a power cut Sunday night while I was on the pc. I unplugged it straight AWAY hoping that would protect it . Power come back so I plugged it back in and turned it on but nothing happened, all I get is flickering light on the keyboard and mouse and nothing else. I'm thinking PSU but not certain. That sound likely? ... Cheers guysWell that would probably be the best place to start.However depending on the situation of the "power out" that could have a large bearing on what damage might have been done.For instance if it was due to a scheduled or even non scheduled loss of power in your area then the damage if any would tend to be less than if it was from a close by lightening strike.One causes power loss the other causes a surge or excess of power instantly. Both are not without possible negative affects on computers.truenorthCheers mate. I did ring a IT expert who said he doubts it's the PSU. He said he didn't think that was the problem due to the fact I'm getting flickering lights on mouse and keyboard. I know from past experience tho that isn't always correct.

"that isn't always correct" your correct that isn't always true. The PSU provides a variety of voltages and via a variety of connectors so while the "expert" may have doubts i personally would want to verify that and eliminate it if possible and the easiest and quickest way is to install (even if only temporarily) a PSU of equal or greater capacity and OBSERVE the results.truenorthToggle the black power switch on the back of the PSU with the PC plug removed...
Un plug it and reconnect to the PC and power back up...Just tried unplugging power chord and plugging it back in, still same OUTCOME. I think my PSU is buggered. I did notice a while back that it was starting to BOOT up slowly. I've read this could be a sign of a dieing PSU, maybe the power cut just finished it off? Did you do as i suggested ? ?Yea mate tried it, same outcome. You think that sounds like buggered PSU? Yepper...
Another item that will cause these symptoms is if it's an older PC that has a modem card it tends to take the 1st hit...if it does remove all power to the PC...remove the card and re-boot.
If the above does NOT apply borrow a known good PSU of the same or greater wattage amd swap it in there overnite to test...

Best of Luck.Pc is around 4 years old mate, I just had a look and I didn't see a modem card. I was told it could also be my graphics cards. I tried disconnecting them as well but that didn't work. I'll try get hold of a second hand PSU and try that. cheers for the help pal Quote from: jay_1978 on June 05, 2012, 09:48:55 AM

Cheers mate. I did ring a IT expert who said he doubts it's the PSU. He said he didn't think that was the problem due to the fact I'm getting flickering lights on mouse and keyboard.

You would be right to doubt this, since it's just plain wrong! A faulty PSU can be the cause of nearly any observable symptom; whether certain lights flash or whether fans spin and so forth isn't indicative that the power supply is working properly, just that those devices are getting power. Sort of like when you have a brown-out, your incandescent light bulbs will still work, but a lot of other stuff might not. The various components in a machine have different tolerances as for how far from the norm they will work.

It might be possible that the power supply is faulty in that it gives PWR_GOOD for a few seconds, then stops. If a machine does not RECEIVE PWR_GOOD, the CPU will sit in a reset loop. If this is the case than the PSU is actually working exactly as intended; parts of it's insides may have been hooped by a surge as the power cut or something to that effect. Good quality power supplies are designed to sacrifice themselves in that case. How a "sacrificed" power supply acts depends on how it was damaged. Not all power supplies just stop working; your's still seems to do something, but something kicks in afterward to stop it from powering up properly.

It could also be the graphics card, too. Really the only way to find out what is wrong is to swap out various parts with known good components.

The only way to really test that though would be to swap in a known-good power supply.
Got some IT bloke coming tomorrow, he reckons it sounds like the PSU, plus the pc was starting to get slower which he said is a indication of a dying power supply. Thanks for all ya help

Solve : No power after power cut?

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