Pc not booting

Soldato
Joined
13 Aug 2012
Posts
4,274
My pc doesn't always boot, the case lights come on and fans spin but no bios screen no keyboard lights and the power and reset button don't work has to be switched off at plug.

It started doing it a few months ago but not very often and it was simple matter of switching off at the plug and switching it on again.

Now it's got to the point where it's everytime I go to use it I have to switch it on and off and the plug a few times. Whats worse now is it will only switch on once a day if I switch it off and go to use it again a couple of hours later no matter how many times I try it will not boot.

I have tried cleaning it.
I have reset bios.
I have changed battery.

My guess is either psu or motherboard????? Any ideas?
 
I have my sons pc here I can borrow his, I will give that a try tomorrow see if it makes a difference.

I kind of hope it is the psu as it has 5 year warranty where as the motherboards 3 years is ran out.
 
I have taken my psu out today which was hard because i have large cooler and small case.

I tried the psu on my sons computer and it works fine?

Does this meen its my motherboard?

Do I need to try a different psu on my machine?
 
You need to try and strip it back to basics, pull the GFX card out and connect directly to the board.

One stick of RAM etc.

Easy the load on the PSU and see if it still does it.

If it does and as you say the PSU seems to work fine in another pc, it could very well be the board.
 
I just done a full swap of psu's and my psu works fine in his pc and his psu in my pc doesn't boot at all no fans no nothing.

I will try without the card and see if it makes a difference

So if it's definitely my motherboard which Im now pretty sure it is what are my options? It's a msi z77 gd65 and its 3.5 years old. Can it be repaired or do I just need to bin it and buy another?
 
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Does the PC's speaker beep when you switch it on? For some hardware errors, it will generate a beep or series of beeps in Morse code. Then on another device you can google it based on what make your BIOS is (usually Phoenix or Award).
 
Faliure to post could be motherboard,cpu,memory or graphics.

Test the GPU in your sons PC as you tested the PSU.
Not the GPU?

Start with onboard graphics and one stick of ram.
if its no good swap the ram over (unlikely to have more than one faulty stick)
Still no good return the motherboard unless you have some way to test the CPU.
Still no good with new motherboard, return CPU.
 
Does the PC's speaker beep when you switch it on? For some hardware errors, it will generate a beep or series of beeps in Morse code. Then on another device you can google it based on what make your BIOS is (usually Phoenix or Award).

My motherboard has never beeped it does have an display with error code 4f. I read online somewhere the error code meens northbridge failed to initialise.

Faliure to post could be motherboard,cpu,memory or graphics.

Test the GPU in your sons PC as you tested the PSU.
Not the GPU?

Start with onboard graphics and one stick of ram.
if its no good swap the ram over (unlikely to have more than one faulty stick)
Still no good return the motherboard unless you have some way to test the CPU.
Still no good with new motherboard, return CPU.

Yes I done all this today. I ran it off onboard graphics and tested with just one stick of ram and tried both sticks.

I have no way of testing if it's the cpu but im pretty sure cpu is fine as once my pc was booted I could use it for days until I switched it off.
 
So I just flicked the bios switch and it booted wtf? Can someone explain this to me what this meens?

I had reset bios multiple times, I even have it out my pc on the side.

This has been a really anoying intermittent problem for months getting worse and worse to the point of where it wouldnt turn on any more.

Then i flick bios switch and it boots first time.





Edit: completely stopped working now its stuck in constant boot loop. Clicks to come on then instant turns off even with no other parts connected.

Edit again.

Bios A: is dead tried reset doesnt even power up just clicks. Reset doesnt make a difference.

Bios B: will start boot but hangs on a0 cant get to bios or windows.

Update: I finally got it in the bios. I been trying for hours and finally making progress. What was holding me back was the B bios was incompatible with my graphics card. You would think easy solution take the card out and run off onboard hdmi, well crazy thing is the onboard is incompatible with the tv that I always use. So for hours I been trying to get it to boot not knowing onboard is incompatible with the tv. I only switched screens so I can watch game of thrones at 2am on my main tv and bios was there.

Its been so stressful I tried ram in every slot, ssd in different sata, multiple graphics cards, multiple resets.

So right now im booted up in bios only have 1 stick of ram in there and no hard drives. Should simply be a matter of plugging in my ssd booting in to windows downloading latest bios flashing them and reinstalling my gpu and ram.
 
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Fully working now on B bios :)

I had actually damaged a hdmi lead at some point during testing which was adding to problems after I switched to B.

A side is gone.
 
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