Computer randomly turning off, odd symptoms

[samboy29]

G'day,

Starting today my computer has been randomly turning itself off, although running lights are still on, and the computer sounds as if it is still running normally.

Essentially what happens is that it crashes out, the monitor says input signal lost and then nothing happens. First two times it crashed whilst using Photoshop. Third time I installed a program to monitor the HDD temp. It was running just over 40c when it crashed again (had a low end game running to see if the HDD temp would rise). I waited 30 min before turning the computer on each time.

Opened the case to check for any build up of dust, it seemed fine.

Edit: I have also checked that all the cables are plugged in correctly.
Also definitely something wrong, because one of the times holding down the power button didn't turn it off. Had to turn the computer off by the switch at the back of the computer. The other times it went to BIOS then turned off.

System:
Windows 7 64
4 GB RAM
2.8GHz Quad core
500GB Seagate HDD

Only thing new with the comp today was updating Microsoft.Net framework, a few hours before the first time it crashed. No idea if that is related or not.

Thanks for all help in advance,

Sam.

 

[Archean]

Firstly, check your system's logs for any clues, you can find them in Control Panel / Administrative Tools / Event Viewer. Check for any Red/Yellow error tags and see whether you can come up with something useful.

Secondly, if you have a restore point before the update was installed, roll back your system to it.

 

[samboy29]

okay, I tried to check system log as instructed. Crashed at the desktop screen while still booting and won't get past that point. Same deal when trying to open in safe mode. Computer started to make odd sounds, so haven't tried to turn it back on.

Have very little experience on the hardware side of things >.> any idea what part may be wrong with it?

 

[Archean]

What sort of 'odd' sound? Is it some type of beeping or is it a mechanical sound?

Have you tried to boot with "Last Good Known Hardware Configuration" ?

 

[samboy29]

Now it is turning itself off (completely now) after about 30 seconds of running (whether or not it is still in BIOS), no sounds now. The sound earlier sounded mechanical, although I'm not sure what part exactly.

No luck running from the Last Good Known Hardware Configuration mode either, unfortunately.

I personally can't even hazard a guess as to what the overarching problem is stemming from.

 

[Archean]

As you said you haven't have any good hardware side knowledge, it can be tricky to proceed. Anyway, my suggestion is :

1. Disconnect HDD Data cable from Motherboard
2. Disconnect DVD Data cable from Motherboard

Try to turn on the system, if system stays on (i.e. doesn't turn itself off), then attach them one by one and see what happens.

If the above doesnt work out, take out all RAM Modules, then place only 'One' in the slot and try to boot again.

IF you don't feel comfortable doing this, I'd suggest you to take the pc to your nearest tech shop.

 

[Archean]

As you said you haven't have any good hardware side knowledge, it can be tricky to proceed. Anyway, my suggestion is :

1. Disconnect HDD Data cable from Motherboard
2. Disconnect DVD Data cable from Motherboard

Try to turn on the system, if system stays on (i.e. doesn't turn itself off), then attach them one by one and see what happens.

If the above doesnt work out, take out all RAM Modules, then place only 'One' in the slot and try to boot again.

IF you don't feel comfortable doing this, I'd suggest you to take the pc to your nearest tech shop.

 

[Archean]

As you said you haven't have any good hardware side knowledge, it can be tricky to proceed. Anyway, my suggestion is :

1. Disconnect HDD Data cable from Motherboard
2. Disconnect DVD Data cable from Motherboard

Try to turn on the system, if system stays on (i.e. doesn't turn itself off), then attach them one by one and see what happens.

If the above doesn't work out, take out all RAM Modules, then place only 'One' in the slot and try to boot again.

IF you don't feel comfortable doing this, I'd suggest you to take the pc to your nearest tech shop.

Edit: Any Moderator reading this kindly delete two of these duplicate posts, as I clicked few times not realizing that my isp is playing up (read slowed down for some unexplainable reasons).

 

[samboy29]

I took it to the shop and had it fixed. Turned out the old PSU wasn't cutting it anymore (which is odd because nothing was added / changed, and the gizmo the guy at the shop had said the Power supply was working properly). Anyway, had it changed and haven't had a problem since.

Thanks for the help mate,

Have a good one.