no display no hdd light only fans

[winkawak]

My desktop has been having boot up symptoms where pc would power up and immediately shuts down then automatically power up again. Sometime it will turn on and off few times before booting up normally. Recently computer wont even boot up anymore, i would get no display and no HDD activity. The only thing is on is the cpu,case and gpu fans. I thought i had a bad psu so i went and ordered another one, computer still sometimes turns on and off but its alot less then before but it still will not boot up. I also have tried different ram and check all my connections, no physical damage on mobo, cleared cmos, bios switch. Do i have a dead mobo?

After countless boot up tries, for some reason i was able to boot up normally this time but not sure how long this well last.

 

[townsbg]

I would check your motherboard's capacitors. How to check your desktop computer for failed capacitors

 

[winkawak]

I would check your motherboard's capacitors. How to check your desktop computer for failed capacitors

All capacitor seems fine. After countless time trying to boot up it managed to boot up again but theres about 1-2minutes delay before display comes on. Also able to boot up normally seems random but does not happen often. As soon as i turn my pc off and try to boot up again its hit or miss probably 90%miss.

 

[townsbg]

I would take the PSU back and try another one.

 

[winkawak]

I would take the PSU back and try another one.

I managed to have it boot up again today trying countless times throughout the day without doing anything different. Once the machine is boot up it has no problems staying on. The problem is once machine is turned off, 99% of time it wont boot up. The psu was also tested before use the fan does spin. You dont think its a mobo problem?

 

[townsbg]

I'm not sure but just because the psu fan spins doesn't mean that the psu is good.

 

[iko22]

I managed to have it boot up again today trying countless times throughout the day without doing anything different. Once the machine is boot up it has no problems staying on. The problem is once machine is turned off, 99% of time it wont boot up. The psu was also tested before use the fan does spin. You dont think its a mobo problem?

Is the PSU new or second-hand? Does it meet ATX 2.4 specification (April 2013)?

See ATX Specification | Tom's Hardware

 

[winkawak]

Is the PSU new or second-hand? Does it meet ATX 2.4 specification (April 2013)?

See ATX Specification | Tom's Hardware

both evga g2 and g3 are atx12v/eps12v

 

[TechnoMage2016]

Because of the weirdities of PSU's, I have purchased several PSU testers over the years.
I also keep a 750W PSU on my parts shelf, just for In-Case.
I also keep several spare PSU/Chargers for my laptops.

A normal PSU is supposed to put out several different voltages. It's possible to have a PSU that puts out 12v+ which is used to run the fans and drive motors, without having the low voltages necessary to power up the motherboard, CPU, etc.

So with that knowledge in mind, checking a PSU is always one of the first things I do, when a computer is having boot up problems.
Just a thought......

Cheers mates!
TM

 

[winkawak]

Because of the weirdities of PSU's, I have purchased several PSU testers over the years.
I also keep a 750W PSU on my parts shelf, just for In-Case.
I also keep several spare PSU/Chargers for my laptops.

A normal PSU is supposed to put out several different voltages. It's possible to have a PSU that puts out 12v+ which is used to run the fans and drive motors, without having the low voltages necessary to power up the motherboard, CPU, etc.

So with that knowledge in mind, checking a PSU is always one of the first things I do, when a computer is having boot up problems.
Just a thought......

Cheers mates!
TM

Thanks
The mobo itself has power/restart led button on the board its self, i noticed these buttons dont light up like before and the debug display also doesnt light up or show display. When it does boot up out of the blue, it seems everything is fine unless i turn the pc off. In really starting to think its a mobo problem. Is situations like this repairable?

 

[townsbg]

Thanks
The mobo itself has power/restart led button on the board its self, i noticed these buttons dont light up like before and the debug display also doesnt light up or show display. When it does boot up out of the blue, it seems everything is fine unless i turn the pc off. In really starting to think its a mobo problem. Is situations like this repairable?

That could be an indication that the psu is bad. Like I said since it is new I'd take it back and say that it isn't working and get a replacement so you can rule that out since you can't take back the motherboard. You have to rule out the PSU anyway. As suggested you can also get a tester and test it. If it is the motherboard technically they are fixable to an extend if you have the parts/equipment and knowledge to do so. You have to decide how much time/money/equipment you are willing to spend on it or if you would rather buy a replacement.

 

[winkawak]

That could be an indication that the psu is bad. Like I said since it is new I'd take it back and say that it isn't working and get a replacement so you can rule that out since you can't take back the motherboard. You have to rule out the PSU anyway. As suggested you can also get a tester and test it. If it is the motherboard technically they are fixable to an extend if you have the parts/equipment and knowledge to do so. You have to decide how much time/money/equipment you are willing to spend on it or if you would rather buy a replacement.

Whats the odds of having two bad psu? Have i mentioned once pc is booted up even during game pc is fine. Just the turning on thats the problem.

 

[townsbg]

A bad power supply can have strange symptoms.