Possible broken PSU? PC won't power up.

[Thebatfink]

Hi, just after some advice before I drop for a new PSU. The last few days I have noticed something strange with my machine. I think its going to sleep (or losing power), but then I can't get it to boot up. The power button does not start up the machine.

I can correct this by turning off the power switch on the PSU for a few seconds - or removing the power cored and replacing after a few seconds, then all is fine.

I do notice however that one of my USB peripherals has a power indicator on during all of this (it stays on during sleep) so some form of power is making its way to the motherboard at least. Its probably worth noting that the first time this happened, when the machine came back up, it complained the bios was broken and restored it automatically from the backup bios. Never seen that before (and the board is only a matter of months old), maybe it was a power surge or cut off?!

I'm wondering if the resetting of the PSU is indicative of a failing PSU or could it be something else, like the motherboard? Just trying to avoid buying a part to replace something that isn't broken and having to buy something else later?

Any thoughts would be appreciated!

[kalniel]

Quite a lot of machines struggle to stably resume from standby/sleep, so I wouldn't say anything is broken. If you go into BIOS you can change the CPU sleep mode to something a little more stable - modes like C3/6/7 are quite advanced, but the basic C1 stop mode is more reliably able to be returned from.

[Thebatfink]

Hi thanks. I will look for that in the bios when I'm back home.

Do you think that could be the case here though? When I press the power button, it literally doesn't turn on, ie, the power buttons light on the case doesnt illuminate, I hear no fans spin up, its like the power is completely off (not to mention its slept and woken ok for several months).

Suppose I ought to give some info on the machine..

AMD FX6100 3.3GHz 6 Core
Gigabyte GA-970A-D3
16GB (10GB System + 6GB Ram Disk)
2 x 120GB Agility 3 SSD in RAID 0
Zotac GTX 660 2GB

[Mr_Jon]

hmmm, i had something similar with an old psu. it didn't like warm weather (or a hot cpu), and would shut itself down and not come out to play for a minute or so afterwards. how are the temps? and has it inhaled a lot of dust?

[kalniel]

Hi thanks. I will look for that in the bios when I'm back home.

Do you think that could be the case here though? When I press the power button, it literally doesn't turn on, ie, the power buttons light on the case doesnt illuminate, I hear no fans spin up, its like the power is completely off (not to mention its slept and woken ok for several months).

Yup that's what I've seen - the power button in this case is only sending a signal to wake up from sleep - same thing as hitting the space bar.

[Thebatfink]

Yup that's what I've seen - the power button in this case is only sending a signal to wake up from sleep - same thing as hitting the space bar.

Ok, I will give this a shot tonight. Strange it would suddenly start doing this though no?

hmmm, i had something similar with an old psu. it didn't like warm weather (or a hot cpu), and would shut itself down and not come out to play for a minute or so afterwards. how are the temps? and has it inhaled a lot of dust?

I haven't checked for any temp readings, I will have to try find a way of monitoring those. But its certainly not just too hot to start up, because I'm talking hours its been off, but will not restart till the power is cut and reapplied (there must be some electrical reset happening in the PSU or Mobo or something).

[kalniel]

Ok, I will give this a shot tonight. Strange it would suddenly start doing this though no?

It's software - a rogue driver or USB device can prevent wake up from sleep quite easily. You can generate a report from Windows on what it thinks the problems might be:
http://www.howtogeek.com/howto/7638/...er-efficiency/

[Thebatfink]

Well if its software, what will messing with the bios achieve? My bios has a setting for C1E and C6. Having read about, disabling C6 will prevent the power saving features of the CPU so I'm reluctant to do it but I have disabled it to see what happens.

I ran the report and it throws errors in the report for practically everything connected via usb to the machine, but I have added no new hardware to the machine in the last x months except for a graphics card (and even that was a month back).

[kalniel]

Well if its software, what will messing with the bios achieve? My bios has a setting for C1E and C6. Having read about, disabling C6 will prevent the power saving features of the CPU so I'm reluctant to do it but I have disabled it to see what happens.

It won't disable all the power saving features, it'll disable the deeper sleep only. Your CPU will still power down in idle and when the computer is sleeping, but it'll use a fraction more power than the C6 halt mode.

Software/USBs could be causing a problem returning from C6 halt mode. Thus to fix it you can either cure the software (hard) or disable the C6 halt mode in BIOS.

I ran the report and it throws errors in the report for practically everything connected via usb to the machine, but I have added no new hardware to the machine in the last x months except for a graphics card (and even that was a month back).

Welcome to the wonderful world of computers. Stuff changes. It shouldn't, but it does. Can be a windows update, could be a virusscanner update.. nothing's static. Might be worth checking for motherboard driver updates (USB, LAN etc.)

[Thebatfink]

So I disabled C6 like you suggested - and its still doing something strange. I basically come to the machine and the power button works everytime, but its cold booting so its either crashed or lost power? How do I debug this now?

I've just disabled sleep and will see if it loses power over the next few hours?