PC boots or doesn't POST

[Strimblaster]

Hi, thanks in advance for reading.

 

It happened during game session my pc rebooted, no BSOD or anything, instant reboot. It happened a few times (curiously only happens in that game) so I monitored thermals with stress tests but turned out all good and the reboots were very rare so I looked away.

This time it didn't turn on anymore, it didn't even POST(No beeps) but all fans start spinning like normal including PSU fan.

 

Fast forwarding to the point I'm at in troubleshooting I narrowed it down to Motherboard or PSU. I took everything out, even took this opportunity to clean everything up.

It now boots like 10% of the times and when it boots it shows all RAM sticks, CPU, disks.

I don't think the times it boot are entirely random, it seems that turning off PSU switch for ~5 minutes and turning it back on always result on successfull first boot. When I turn the computer off or I reboot it or I make any change in the BIOS and it has to reboot, almost never POSTs.

 

Other things I've done:

• Reseated RAM a lot of times and tried every stick individually.
• Took RAM off and started the computer from that state that it almost always boots and it beeped. If I turn it on without waiting for that "cooldown" it doesn't beep
• Used a very old PSU and got the same result. I dont know to which point this is valid to say that the PSU is not the problem because this one I tested dont even have 24 pin connector, it's 20. Other thing to consider is that at high power usage this PSU might not be working properly and could be the cause of this (probably) motherboard problem.

 

It seems that the motherboard is the problem but I'm not 100% sure so I'm hoping someone can give me an opinion on this.

Observation: I've read the readme about no post problems before writing this and I basically tried everything it says there and it comes to the same conclusion as me: "most likely motherboard".

 

Specs:

• CPU - Intel I5 4440 3.1GHz, stock cooler
• RAM - 12GB DDR3 1600mhz
• Motherboard - MSI B85M-E45
• GPU - MSI NVIDIA GTX 970 4G (I troubleshooted always with iGPU but it's here anyway)
• PSU - Corsair CX600 600w
• SDD - Samsung 750 evo 120gb
• HDD - WD Blue 1TB 7200RPM

[Radium_Angel]

7 minutes ago, Strimblaster said:

PSU switch for ~5 minutes and turning it back on always result on successfull first boot

Bad PSU.

[Strimblaster]

2 hours ago, Radium_Angel said:

Bad PSU.

What makes you so sure? Is there some explanation behind it?

Sorry but because I used another PSU (old but still) and I got the same problem leads me to believe that it's not.

 

Thank you for the answer.

[Radium_Angel]

4 hours ago, Strimblaster said:

What makes you so sure?

My experience as an IT pro for years and years and years. A new PSU solved the issue 99times out of 100.

The other 1 was, as you suspect, a bad mobo.

 

But it's easier to swap PSU than mobo, so I'd simply start there.

[Strimblaster]

On 9/5/2020 at 12:34 AM, Radium_Angel said:

My experience as an IT pro for years and years and years. A new PSU solved the issue 99times out of 100.

The other 1 was, as you suspect, a bad mobo.

 

But it's easier to swap PSU than mobo, so I'd simply start there.

Well it wasn't PSU. I bought a Corsair RM650 and it's still the same... Guess I'll have to buy a mobo

[Radium_Angel]

32 minutes ago, Strimblaster said:

Well it wasn't PSU. I bought a Corsair RM650 and it's still the same... Guess I'll have to buy a mobo

Well that's a kick in the teeth...

Finding a new mobo for an old CPU might be a trick, though there are plenty of used ones floating about