Question PC is not turning on --- PSU, RAM & HDD are fine.

[ramanbhadu]

CPU INTEL - G4400 5-year-old
MB- MSI 110 pro vdh - 5 years old
PSU - COOLER MASTER 350 - 4 years old
1 TB HDD - 5 years old
ZOTAC MINI 1050Ti -2 years old
8+4 GB RAM- first 3 years only one 4 Gb stick from last 2 years the second stick is installed.

Never had any kind of problem before this.

I have removed the GPU and connected the display to MB.
I have tried my PSU on another PC it worked fine
Other PSU on my PC not turning on.
My RAM and HDD in another PC working fine.
I have taken out every component from my case and cleaned them but still not turning on.
I don't have thermal paste so did not remove the processor from MB. There is no physical damage visible on the MB as shown in the benching guide of the website.
I removed CPU 4 pin connector and kept the cpu fan connected still no fan spinning

The sequence of instances-
1 PC was perfectly working and I shut down it.
2 Next day I pressed the power button but nothing happened. No fan spinning no beeps no lights. I put the PC in sunlight and tried in the evening and it worked fine. Again I hibernated it and then tried to start not started the same as the previous one.
3 Again put in sunlight but no changes.
4 I removed the CMOS battery and put it back and the PC started fine worked for 10 minutes and then switched off on its own.
Again removed CMOS just CPU fan spins and stops within a half-second.
I changed the CMOS with a new battery.
5 When I press the power button without removing CMOS nothing happens no fan spinning no lights in MB but when I try after removing and putting back the CMOS battery the fan spins for some seconds and then stops.

 

[Lutfij]

Coolermaster is the brand of the PSU, while 350 is the advertised wattage of the unit. You forgot to mention the model of the unit. How old is the unit in question? What is the make and model of the donor PSU? Does the system remain powered up without the discrete GPU populating the motherboard? Take out one stick of ram and see if that helps you. FYI, you shouldn't mix and match sticks of ram. You should go for a 2x4GB layout or a 2x8GB layout, note somewhere in between.

 

[chaoyang]

So no fan noise from PSU when you turn on the switch?

Sometime when cleaning PC, we can forget to plug back in our PC or turn on main switch, PSU switch etc.

 

[ramanbhadu]

Coolermaster between.

My PSU is 4 years old and the donor is 1 year old. PSU model if it makes a difference is below. Both are working perfectly fine on another PC.

https://www.coolermaster.com/catalog/legacy-products/power/elite-power-350w/#specifications

I have checked my PSU on another PC and that PC worked fine
I tried my PC with donor PSU but nothing changed.
I have had these two RAM sticks for the last 2 years and never faced any problem.
I have had the GPU for the last 2 years without any problems and it is working fine on another PC now.
I have tried with and without the GPU installed in my MB but nothing happened.

 

[ramanbhadu]

So no fan noise from PSU when you turn on the switch?

Sometime when cleaning PC, we can forget to plug back in our PC or turn on main switch, PSU switch etc.

No, the fan only spins when I remove the CMOS and install it back, and that is only for 1 second.
I have checked all the connections at least 10 times but no connection is loose and forgotten. Everything is connected where it should be.