I have a bit of an issue with an old PC setup I use in the garage.

 

The last week or so when you power up the tower it starts as normal and load screen comes on the monitor, After 30 seconds it just dies completely.

Monitor goes into sleep mode and the Tower loses all power. It will start up straight away when the power button is pressed but the monitor is staying in sleep mode.

 

Switching both off and back on still sees the monitor in sleep, If I disconnect the monitor from the tower the monitor powers up but immediately goes into sleep mode when connected to the tower again.

 

Are the tower dieing and monitor going into sleep related?

Does it sound more like graphics card or PSU faulty?

 

Any advice other than bin it all

Monitors go into sleep mode when they get no video signal from the PC. You say an old PC, so I am assuming you are using a VGA monitor connecter. The 15 way D type just over a cm wide.

Obviously a spare monitor swap would prove if the fault was PC or Monitor based if you had one handy.

If you keep pressing F8 as the PC boots, it should bring up the Safe Mode Menu. Keep pressing F8 as soon as you turn the PC on. You may have to do an OK on a keyboard error question, but ultimately you should get the Safe Mode Boot Menu.

So 1st question. If you just wait a while on that menu without doing anything then that proves the monitor is at least stable in a basic mode to be on for while.

Once happy then select Safe Mode. Windows then boots into Safe mode with a low Video resolution. Another reason monitors shut down is if you run them at a higher resolution than they can handle, some higher end monitors will tell you that on their screen others just shut down.

So again is the monitor and picture stable when all booted up in safe mode ?    If so I would recommend setting the Video card resolution to 800 x 600. You can just right click a blank area of desktop and choose Properties to do that.

Then reboot normally and assuming you have a picture up the resolution from there, confirming on each step the picture remains.

Edited 10 January, 201610 yr by aubrey

Another possibility, the cpu fan has died/fallen off/clogged up, and the system is shutting down before the boot sequence can finish due to an over-temp warning; start-up is one of the most stressful times for the cpu heatwise.

Does it have a gfx card?

 

could be driver issue which should show up if you boot into safe mode

I have a bit of an issue with an old PC setup I use in the garage.

 

 Tower loses all power.

 

 

If the tower is losing power  - I'd suggest it's either the power supply or it's just broken (motherboard blown some capacitors for instance). It could be as Gentle Giant that the CPU is overheating very quickly. From the sound of it you can't even boot it - does it beep at all?

Edited 11 January, 201610 yr by io1901

If the CPU is overheating I wonder if you could get into the BIOS quick enough (if you know how to) and check the CPU temps.

It's not a corrupt windows because if I was then the PC would just keep restarting.

Failed hard drive - no, doesnt cause it to shut down.

Motherboard - possibility as said above.

PSU - quite possibly as said above, if it's an old PC then I'm assuming it's an onboard gfx card and an old CPU so doesn't really require a lot of umph to keep it running BUT if its old like you say it could be on its way out.

Don't suppose it's been knocked recently? Could of knocked a wire or something?

I've just realised you're only in manchester, where abouts? I'm in oldham so not that far away.

Edited 11 January, 201610 yr by LGM

I'd be very surprised if the CPU was over heading that quickly. Even if the heatsink had totally fallen off.

 

Weird errors imho are usually motherboard related. Might be worth having a look at the mobo carefully and checking the capacitors for swelling or bursting. If any of them have gone off it can make fore some strange errors. Admittedly not seen that for a few years now (there was a bit of a plague of this some years back due to botched industrial espionage).

 

Might be worth taking everything apart and plugging it back together again just in case something has worked free.

 

As an outside option has anything been dropped in the case? Had a PC once with some really odd behavior turned out to be a loose screw under the motherboard making a short circuit.

Sounds like its finding something in the POST (power on self test) that it doesn't like and is not booting to prevent further damage. It could literally be any component.

Duff memory module, CPU, gfx card etc. Sounds like you have been using it for a while so I would say its more likely hardware failure than a driver issue. Sleep mode is a bit of a red herring for non techs. As someone pointed out if the monitor stops getting a signal via the VGA Dsub then it will automatically go into sleep. All that you can derive from this is that the computer is not outputting to the monitor, or its outputting a resolution not supported by the monitor the former being the more likely. This unfortunately does not help diagnose the issue. All you can really do is bash the F8 key to boot in safe mode if that works try the f key to get into bios and do a memory scan etc. Dead memory module is my guess. If you have more than one try pulling one and booting then the other. It will be slow but at least you can rule one possible cause out.

As Aspman suggests, I think your best option here is to take the side off and reseat all the cables and cards in case something has been knocked or vibrated its way loose. While it's open, use compressed air and a soft bristled paintbrush to clear out as much dust as you can - it may well be caked all over heatsinks, fan grills etc and be causing overheating.

Also see if any fans are failing to spin up when you hit the power button (if the bearing has gone on the CPU heatsink fan that could cause rapid overheating and shut down).

You could also see if there are any unused things draining PSU power that you could unplug (extra hard drives, PCI cards, modems etc.) as computer PSUs deliver fewer and fewer watts as they age, and your supply marked 500w might now only be delivering a fraction of that.

If none of that works it could be pretty much anything on the mainboard, like Scribbler says. If it's a fair age then I wouldn't bother troubleshooting further personally, unless you've got a lot of patience. If you're just doing basic desktop and internet stuff with it a £30 Raspberry Pi will handle most of the tasks that a 10 year old PC that cost £800 at the time will, with the added benefit of super low power draw, silent running and instant boot up.

Does it have a gfx card?

 

could be driver issue which should show up if you boot into safe mode

 

Yes I bet this is the issue or the machine is set at a resolution the monitor cannot support so you then get nothing on screen.

Could be many things....

 - Doesn't read like PSU failure but could be.

 - Heat issues - a stuck CPU or GPU fan....

 - Or even a failed HDD.

 

Can you boot it into BIOS and get a PC Health status display?

Any beeps after its tries to load?

Any beeps after its tries to load?

 

Especially if it boots with the monitor in sleep.

 

There is a beep code for failed graphics (I think).

Sorry guys, Been a little busy of late.

 

I'll try to explain as best as I can.

I bought the tower about 3 years ago from a mate, I think it's something he built. It had little use until I moved out of my unit and started using my home garage to work on cars.

The only thing it's for is keeping records of vehicles worked on and browsing the web.

 

Anyway the graphics card looks quite decent, It's a sapphire with built in fan. I do however have to use an adaptor for the monitor plug as the card doesn't use standard VGA.

 

I had a quick look and can't seem to find anything unplugged slightly.

I'll clean out all the dust and double check cables.

The heatsink and fan are still in place.

 

I did manage to get it booted up and running the other day but it it again playing up like before.

Any beeps after its tries to load?

 

Tbh I don't always turn the speaker on. I will try it with the speaker on and see if there's any error beeps.

Yes I bet this is the issue or the machine is set at a resolution the monitor cannot support so you then get nothing on screen.

 

I've not changed any settings and the monitor used to run fine with the tower.

Tbh I don't always turn the speaker on. I will try it with the speaker on and see if there's any error beeps.

 

Beep codes come from a little speaker built into the motherboard, you don't need to turn the real speakers on (they're from the good old days of dip switches and jumpers).

I think we can assume you're not getting any.

 

The adapter on the graphics cars sounds like it's a DVI to VGA adapter. If it's all snugly fitted together probably not a problem.

 

[clicky click] Spotted something that reminds me of a PC I fixed a loooong time ago. Power switch on the front of the case was broken.

If you can find the little cable coming from it, trace it back to the motherboard.

If you're feling brave either

 

start the machine then gently pull the cable from the mother board

or remove the cable and start the pc by shorting the two pins momentarily with a screwdriver or jumper.

Beep codes come from a little speaker built into the motherboard, you don't need to turn the real speakers on (they're from the good old days of dip switches and jumpers).

I think we can assume you're not getting any.

 

The adapter on the graphics cars sounds like it's a DVI to VGA adapter. If it's all snugly fitted together probably not a problem.

 

[clicky click] Spotted something that reminds me of a PC I fixed a loooong time ago. Power switch on the front of the case was broken.

If you can find the little cable coming from it, trace it back to the motherboard.

If you're feling brave either

 

start the machine then gently pull the cable from the mother board

or remove the cable and start the pc by shorting the two pins momentarily with a screwdriver or jumper.

 

I wouldn't advocate doing any of Above as a novice. Infact I wouldn't do the above and Im a tech.

If your doing anything with the case lid off make sure you unplug from the mains first.(sounds obvious but

easily forgotten when trouble shooting).

 

I still think its a peripheral failure most likely the memory Module. Could be the memory on the GFX

Card also you If its got a VGA out on the motherboard (on board graphics you could pull the Saphire and

try and boot.

Any chance of posting a video of it booting up? 

Are you able to try it with a different monitor?

 

And does the motherboard have on-board video? If so, you could remove the dedicated graphics card and try booting up with the monitor connected directly.

 

Will just help narrow down the list of potential issues.

What's the beep code coming out of the system (Eg when it beeps how many and are they short of long etc).