Motherboard not turning on

[dpservis]

Hello,

I upgraded my PC and the motherboard will not turn on. It turned on once, I saw the bios, saved and exited without changing anything, there was a screen which I do not remember what was on it (some kind of loading message) and then the computer turned off. I tried to turn it on and since then it only gives a turn to the chassis fan and stops. The "on" led is lit. I tried resetting the bios (jumper, battery, both) no luck. I removed everything but the CPU, nothing.

When I remove the 12v ATX all 3 fans (PSU, chassis and CPU) turn on, but after the CPU fan turns on the whole system turns off and enters a continuous cycle of turning on-off.

Here's the upgrade hardware
Asus P8Z77-M PRO, Z77, LGA1155, PCI-E 3.0
Intel Core i5 3470 BOX, LGA 1155
Kingston HyperX Blu, 2x8GB, DDR3-1600, CL10@1.5V

Any ideas will be highly appreciated.

 

[cmichael138]

what's the PSU specs?

 

[dpservis]

what's the PSU specs?

It's an LC power 420H. Thanks!

 

[MonkeyManHArd]

Did you make sure every all the power connectors are connected to the motherboard?

 

[mlcaouette]

Power supply is very low end, possibly the problem. Are the M/B stand offs installed? Are you using a discrete or on die graphics?

 

[MonkeyManHArd]

I don't it's the PSU's fault. I can't help further sorry.

 

[mlcaouette]

@MonkeyManHard:

Perhaps you haven't heard the saying, you buy cheap, you buy twice. This is especially true when you're talking about power supplies.

I suggest testing the power supply or trying a different (better) PSU in your system.

 

[MonkeyManHArd]

@MonkeyManHard:

Perhaps you haven't heard the saying, you buy cheap, you buy twice. This is especially true when you're talking about power supplies.

I suggest testing the power supply or trying a different (better) PSU in your system.

It's not my problem

 

[dpservis]

Hi all thanks for the answers

the PSU was in the Asus box of my previous PC, served me for 4 years until today. Maybe it is indeed low-end for this setup? Any suggestions?

Nevertheless, the PC did start once and got in the BIOS but when I saved and exited it went into a couple of other screens and shut down (there was a second screen I did not have the time to see what was written). I wonder if there was something badly written and needs some special way to reset?

I removed my graphics card but the problem is still there.

The casing does not have separate standoffs but bent cutouts at the internal chassis.

 

[MonkeyManHArd]

Hi all thanks for the answers

the PSU was in the Asus box of my previous PC, served me for 4 years until today. Maybe it is indeed low-end for this setup? Any suggestions?

Nevertheless, the PC did start once and got in the BIOS but when I saved and exited it went into a couple of other screens and shut down (there was a second screen I did not have the time to see what was written). I wonder if there was something badly written and needs some special way to reset?

I removed my graphics card but the problem is still there.

The casing does not have separate standoffs but bent cutouts at the internal chassis.

I'm afraid you need a new PSU, but don't be sad, a good power supply is cheap.

 

[mlcaouette]

I'd be a little bit hesitant about not using stand offs, I'm not fully convinced you're not shorting the system. Could you try bread boarding the system with the M/B box or any piece of cardboard.

Curious MonkeyManHArd, what made you change your mind about the PSU? A few posts ago you seem to think it wasn't the power supply, now without any more info on the power supply you're saying that it is indefinitely the problem.

 

[MonkeyManHArd]

I'd be a little bit hesitant about not using stand offs, I'm not fully convinced you're not shorting the system. Could you try bread boarding the system with the M/B box or any piece of cardboard.

Curious MonkeyManHArd, what made you change your mind about the PSU? A few posts ago you seem to think it wasn't the power supply, now without any more info on the power supply you're saying that it is indefinitely the problem.

Let me say on the easy way. I didn't think it about

 

[boulbox]

a nice and cheap and reliable one
http://pcpartpicker.com/part/xfx-power-supply-p1550sxxb9

 

[dpservis]

I will try breadboarding and see how this works. My case has "domes" similar to this one

http://www.hardwaresecrets.com/fullimage.php?image=12611

So the consensus is to change the PSU I guess. Is there any explanation why it started once?

 

[dpservis]

Ok i did the following:

1. Used the usb flash bios utility to update the bios and tried again to turn it on. Bios updated properly but when i tried to turn it on it again powers up for a split second and ceases.
2. Did the breadboarding (CPU+2 RAM modules). No effect, i.e. does not turn on. i noticed there is a buzzing sound coming from the PSU for a split second then it stops.
3. Did the breadboarding with the old motherboard and the same configuration (i.e. CPU+2 RAM modules) and it works. Therefore the PSU is at least known to still work.

To me it is still a mystery why it turned on the first time, then off aster the bios setup and died. i wonder if it is a problematic motherboard.

 

[dpservis]

I can readily buy one of the following PSUs to see if it is the power supply that creates the problem:

be quiet! Pure Power L7-430W, 80 plus Bronze
Antec High Current GAMER Serie, HCG-520, 80Plus Bronze
be quiet! Pure Power L7-630W, 80 plus Bronze
be quiet! Pure Power CM L8, 530 Watt, 80 plus Bronze

any ideas?

Thanks!

 

[mlcaouette]

Since you know the power supply, cpu, and ram all work. It is likely the M/B which has failed.

I'd still recommend a better PSU in the future.

 

[dpservis]

Since you know the power supply, cpu, and ram all work. It is likely the M/B which has failed.

I'd still recommend a better PSU in the future.

Should have mentioned I checked the PSU with my old CPU+RAM...

I swapped the MB but did not work.... more trouble here