PC won't boot. Suggestions required.

Si_CreweSi_Crewe Posts: 40,202
Forum Member
So, I was reading a book last night and the noise of my PC fan was bugging me and, for some reason, I decided to press the "suspend" button on my keyboard rather than switch the PC off properly.

I should say, I don't switch my PC off every night but I do switch it off about, maybe, 4 nights a week (by shutting it down completely) and there have NEVER been any problems restarting it.

Anyway, came to switch it on this morning and it's not playing ball.
Pressing the "suspend" button on the keyboard (or any other button) does nothing.

Unplugged it at the wall, left it for a couple of minutes and then tried to start it up and all I get is a brief (about 1 second) whir of the PSU and CPU fans and then nothing.

If I leave it, the PSU and CPU fans repeat the short whir every 30 seconds or so.

Took it all to bits, tested the voltages on the PSU and they're all okay.
Took the battery out of the mobo', reset the CMOS and then hooked the PSU up to it.

With NOTHING (No gfx card, HDDs etc) else plugged into the mobo except the ATX connector the PC seemed to power up.

I plugged the HDDs back into the mobo and restarted it and it powered up but I noticed that neither the "system" or "HDD" front panel LEDs were lit.
It's as if there's basic power getting to the mobo but it doesn't seem to be booting or doing anything "clever".

Plugged the GFX card back in so I might see what was going on and it's back to doing the 1-second whir and then going quiet for 30 seconds again.


So, thing is, if anybody else posted this I'm sure most people (including me) would guess that it's probably a PSU fault.
I'm leaning toward it being a PSU fault but it just seems like a bit of a coincidence that I've never had any previous problems with the PC booting and that it's just decided to throw a wobbly after doing a "suspend", which I don't usually do.

Does anybody have any suggestions for things I might try or things I might test before I order a new PSU?

Comments

  • alternatealternate Posts: 8,110
    Forum Member
    Sounds more like a mother board issue - try jumping the PSU connector (you can google for this under PSU test e.g. http://www.overclock.net/t/96712/how-to-jump-start-a-power-supply-psu-test-a-power-supply-and-components) and see if the PSU fan funs without being connected to the motherboard.
  • Si_CreweSi_Crewe Posts: 40,202
    Forum Member
    alternate wrote: »
    Sounds more like a mother board issue - try jumping the PSU connector (you can google for this under PSU test e.g. http://www.overclock.net/t/96712/how-to-jump-start-a-power-supply-psu-test-a-power-supply-and-components) and see if the PSU fan funs without being connected to the motherboard.

    How do you think I managed to test the PSU voltages? ;)

    What makes you think it's a fault with the mobo?
  • djclewes1djclewes1 Posts: 175
    Forum Member
    when the fuse inside the power supply unit went on mine i had this exact same problem. cheapest way is try a different kettle lead in the pc first. but it was the actual psu fuse on mine that blew.
  • Si_CreweSi_Crewe Posts: 40,202
    Forum Member
    Well, here's an odd thing...

    Ordered a new PSU and it's just arrived.
    I've got the mobo sitting on a bench with the gfx card plugged into it.
    Plugged in the new PSU, started it up and the CPU fan and the gfx card fan both spun up properly and then, thankfully, I got the POST "beep" which indicates that the computer is alive. :D

    The odd thing is that, after starting up the PC with the new PSU, I reconnected the old PSU, gave that another try and found that now works too! :confused:

    I'd previously checked the voltages in the old PSU with no load on them AND checked them while the PSU was attached to the mobo and attempting to boot up and they were always okay, which actually worried me because it suggested the PSU might not be the problem.

    I'm guessing that the problem is/was actually that there's some compatibility or standardisation issue between my mobo and the old PSU which meant that after I'd put the PC in "sleep" mode the mobo (a Asus P5e-VM) wasn't sending a "wake up" signal to my old PSU, whereas the new PSU is accepting whatever "wake-up" signal my mobo was trying to send.

    Funny thing is, while googling for solutions, I've seen quite a bit of stuff relating to the P5e-VM mobo not coming out of sleep mode properly with the Linux OS.
    I'm wondering if all those frustrated Linux programmers are actually on the wrong track and the problem is actually a fault with the P5e mobo?

    Anyway, that POST beep has cheered me up a lot.
    Time to rebuild the beast and see if it's actually fixed. :o
  • Akane TendoAkane Tendo Posts: 4,454
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    So is there any other way you could have fixed this? Seems a waste to go out buying a new psu when the old one wasn't broken.
  • Si_CreweSi_Crewe Posts: 40,202
    Forum Member
    So is there any other way you could have fixed this? Seems a waste to go out buying a new psu when the old one wasn't broken.

    No idea TBH.

    I don't know whether the problem lies with the mobo or the PSU.

    I suppose that it might've been possible to find out how the mobo goes about waking up once it's been suspended and then try and replicate that signal somehow.

    It's a bit of a chicken & egg situation, though, because there's no way of knowing whether the mobo is at fault for not sending a suitable "wake up" signal to the PSU or whether the PSU was at fault for not responding to a standard "wake up" signal from the mobo.

    I guess I'm just going to have to put it down to general "incompatibility" and be glad that it's been resolved.

    Worth bearing in mind, however, that if you have a PC that won't wake up after being suspended, it might be that all it needs is a "jump start" from a different PSU (and then NOT using the suspend feature again, I guess) rather than buying any new parts.
  • Andrew_BallardAndrew_Ballard Posts: 1,054
    Forum Member
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    Can you install the ram in the other slots? I had a PC that suddenly stopped booting (simply cycled) unless you did it 30 times, swapped ram in frustration and it works flawlessly now.

    Same computer also won't boot if I use a certain CPU fan....weird thing.
  • Si_CreweSi_Crewe Posts: 40,202
    Forum Member
    Can you install the ram in the other slots? I had a PC that suddenly stopped booting (simply cycled) unless you did it 30 times, swapped ram in frustration and it works flawlessly now.

    Whenever I'm doing stuff like this I always just remove the RAM from the mobo completely before monkeying around with anything.

    Anything that you can remove from a computer is just another possible cause that you can eliminate.
  • [Deleted User][Deleted User] Posts: 36,630
    Forum Member
    Funnily enough I have a similar issue today.

    Self built PC working without issue for the last three years, shut down properly last night as normal.

    Went to power on this morning and nothing, no lights no fans. Cover off and green LED on motherboard is lit, but no fans running and no startup, not even POST. I did notice some fluff and dust at the back of the power supply and on the CPU cooler fan, so carefully cleaned it all up. Now when the power switch is pressed the CPU fan makes a half turn but no fan on the power supply, so I suspect the power supply is indeed fried.

    Tried the following:

    Removed memory modules.
    Disconnected all cables and components.

    Tried a new kettle lead, no joy.
    Tried to power up with only CPU and cooler installed, no joy.
    Unfortunately I don't have a miltimeter to test voltages from PSU so it's a case of trial and error.

    Oh well, back to this ten year old 256Mb WinXP laptop for a couple of weeks until I can afford a new PSU.
  • [Deleted User][Deleted User] Posts: 36,630
    Forum Member
    P.S. any further suggestions gratefully received. :)
  • brillopadbrillopad Posts: 3,226
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    P.S. any further suggestions gratefully received. :)

    Connect the green wire coming from the psu to any black wire will force the psu to start - if it's not broken.
  • [Deleted User][Deleted User] Posts: 36,630
    Forum Member
    brillopad wrote: »
    Connect the green wire coming from the psu to any black wire will force the psu to start - if it's not broken.

    Tried that, no joy.

    I'm pretty sure I have a spare ATX power supply in a box in the garage, i'll look for it tomorrow. If not i'll just have to buy another when funds allow.
  • [Deleted User][Deleted User] Posts: 36,630
    Forum Member
    All working again. I did indeed have a spare ATX 700 watt power supply, still boxed up in the garage.

    All's well that ends well. :)
  • [Deleted User][Deleted User] Posts: 2,078
    Forum Member
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    Si_Crewe wrote: »
    No idea TBH.

    I don't know whether the problem lies with the mobo or the PSU.

    I suppose that it might've been possible to find out how the mobo goes about waking up once it's been suspended and then try and replicate that signal somehow.

    It's a bit of a chicken & egg situation, though, because there's no way of knowing whether the mobo is at fault for not sending a suitable "wake up" signal to the PSU or whether the PSU was at fault for not responding to a standard "wake up" signal from the mobo.

    I guess I'm just going to have to put it down to general "incompatibility" and be glad that it's been resolved.

    Worth bearing in mind, however, that if you have a PC that won't wake up after being suspended, it might be that all it needs is a "jump start" from a different PSU (and then NOT using the suspend feature again, I guess) rather than buying any new parts.

    Look for a BIOS update for the board if that fixed the problems.

    There's a couple of different Asus P5e-VM boards

    P5e-VM DO (watch for service jumper setting and RAM slots)

    http://support.asus.com/download.aspx?SLanguage=en&p=1&s=22&m=P5E-VM+DO&os=&hashedid=BcnnZhKxoh65jfIC

    P5e-VM SE

    http://www.asus.com/Motherboard/P5EVM_SE/#support_Download_24

    if it's the P5e-VM DO/NA there's only 1 release, so no joy,

    P5e-VM HDMI

    http://www.asus.com/Motherboard/P5EVM_HDMI/#support_Download_24
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