Question PC won't consistently POST or start up ?

[mithrantor]

Hello everyone, first time poster here, apologies if I am in the wrong section.

A few weeks ago I started to have some issues with my desktop computer which has been working great for the last 3 years.
I have limited knowledge regarding electronics and I am not comfortable performing any advanced manipulations.

Long story short, I cannot consistently turn on my computer. Most of the time now I if try to turn it on some LEDs will turn on for a less than a second, and everything then immediately shuts down (together with a 'click' sound). It does turn on from time to time. If started, then it works perfectly.

Regarding LEDs :
On the mother board, the three LEDs lightning up are the DRAM, VGA, and BOOT ones. The CPU LED doesn't light up. The LEDs of the fans on the front panel also turn on for a brief moment.

Regarding frequency :
If the PC is running, it will not power back on right after a shutdown. I found that switching off / discharging /disconnecting the PSU for a while (a few hours...), allows me to turn it back on again.

So far I have tried a couple of simple things, none of them allowed me to turn it on more consistently.

• Used a different power socket / power cable
• Tried disconnecting as many components from the MOBO as possible.
• Removed CMOS battery for a few minutes.
• Checked for dust but the PSU and overall machine are clean (disconnected, took out, and cleaned everything).
• Checked for obvious risks of shorts.
• Went through this checklist .

I don't know many things about hardware but from browsing other posts I suspect that either the PSU or the MOBO are experiencing some issues. I do not have access to a spare PSU to directly check if it is the issue.

I am considering taking the machine to a technician but would greatly appreciate any advice you can give me.

Components:
PSU - COOLER MASTER MWE 750 WATT 80+ GOLD
MOBO - MSI B450 GAMING PLUS
GPU - MSI RTX 2070 ARMOR 8GDDR6
CPU - AMD RYZEN 5 2600 (3,4Ghz 6 cores 12 thread)
RAM - (1x16GB) Crucial Ballistix 16GB 2666Mhz
Cooler - AMD Wraith Stealth Cooler

If there is anything I have missed out please let me know.

 

[Jia Sharma]

Upgrade your BIOs software. I think this is because your BIO's software is corrupt upgrading it maybe helps you out.

 

[Grobe]

In theory, it can also happens in case of corrupted RAM stick's - example from similar thread:

Motherboard CPU light not working

Hi I'm building my first pc and I put everything together being extra careful, using a static bracelet, making sure not to drop anything and I put everything together according to a guide I found and everything went well until I booted up the PC. There were no beeps or buzzes but the CPU LED...

forums.tomshardware.com

What you can do - go get Memtest86 (ships along with Ultimate Boot CD and also most Linux distros as a boot option, e.g. Linux Mint). Let it run for some hours and see if it pick up on any errors.

 

[Vic 40]

Can make a bootdrive with just memtest86 on it, no need for it to be in a package.

 

[mithrantor]

Thank you all for these suggestions.

In theory, it can also happens in case of corrupted RAM stick's - example from similar thread:

Motherboard CPU light not working

Hi I'm building my first pc and I put everything together being extra careful, using a static bracelet, making sure not to drop anything and I put everything together according to a guide I found and everything went well until I booted up the PC. There were no beeps or buzzes but the CPU LED...

forums.tomshardware.com

What you can do - go get Memtest86 (ships along with Ultimate Boot CD and also most Linux distros as a boot option, e.g. Linux Mint). Let it run for some hours and see if it pick up on any errors.

I cannot get it to boot at all for now, so will try this when possible.

When I try to start the machine without any stick I still experience the same behavior. Most of the time nothing happens (or brief LED blink). And sometimes it does power on and then the MOBO correctly indicates that memory is missing. So overall it does not seem to me that my memory is the source of the issue.

Upgrade your BIOs software. I think this is because your BIO's software is corrupt upgrading it maybe helps you out.

The fact that I am sometimes able to correctly boot the machine and use it makes me think that the MOBO is ok as well (it also seems to correctly detect when something is wrong, like missing RAM). Could it sill be corrupted and only works from time to time, in very specific cases?
In any case, would it be safe to still attempt to flash the BIOS without completely disconnecting the MOBO? I am not very willing to remove the CPU and risk damaging anything in the process. Especially if I am not sure that this would solve the issue.

 

[Phillip Corcoran]

Too bad you don't have access to a quality PSU you could temporarily borrow because your symptoms suggest it could well be that. At the very least it's something that needs to be eliminated as the cause before troubleshooting elsewhere.