# [SOLVED] No Post. PSU?



## mrtacoma (Jan 17, 2014)

Hi everyone. I hope you can help me with this.

The other day my screen went black. When I attempted to restart I got a beep, the motherboard splash screen would show for about one second then blackness.

I stuck in a fresh RAM stick hoping for a cheap fix but no such luck. I went ahead and bought a new motherboard, CPU and RAM. The new MB has onboard video so I attempted to start things up without my video card just in case and the exact same thing is happening! Beep, splash screen, darkness.

The old motherboard was in there for two years without a problem, so I assume the case isn't the culprit but I pulled the motherboard and tried to fire it up outside the case with only the keyboard and monitor hooked up just to be sure. Same thing. 

Unless the case did something irreversible to the MB the only thing left is the PSU (unless the keyboard or monitor is causing it but I'm not prepared to wrap my brain around that) I guess.

Has anyone heard of a faulty PSU causing symptoms like this though?


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## greenbrucelee (Apr 24, 2007)

*Re: No Post. PSU?*

faulty power supplies can cause all sorts of problems from what look like software problems to not booting.

A single beep indicates all the hardware and mobo is fine. One way to determing if it is the motherboard is to pull all the RAM out and try and boot if you don't get a series of beeps to indicate no RAM is installed then your mobo is knackered.

please post your full specs
including make model and age of power supply


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## mrtacoma (Jan 17, 2014)

*Re: No Post. PSU?*

Thanks for responding. 

The mobo does beep repeatedly without ram. 

The PSU is a cooler master gx 750w. It's two years old. 

Mobo: Asus M5A78L-M usb3
CPU: AMD FX 4130
RAM: evo veloce ddr3 4gb stick

All three are new out of the box. 

It's so weird that with all that new stuff the symptoms are identical.


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## mrtacoma (Jan 17, 2014)

*Re: No Post. PSU?*

I guess I'll buy a new PSU.


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## Tyree (May 10, 2009)

*Re: No Post. PSU?*

Do you have or can you borrow a known good PSU to try?

Set the motherboard on a non conductive surface. The motherboard box is perfect for this. DO NOT PLACE THE MOTHERBOARD ON THE STATIC BAG! It can actually conduct electricity! 
Install the CPU and heat sink. 
Install 1 stick of RAM.
Install the video card and attach the power supply connection(s) to the card if your card needs it.
Connect the monitor to the video card.
Connect the power supply to the motherboard with both the 24pin main ATX Power connection and the separate 4 pin (Dual Core CPU) or 8 pin (Quad Core CPU) power connection.
Connect power to the power supply.
Do NOT connect ANYTHING else. Make sure you have the power connector on the CPU fan connected.
Use a small screwdriver to momentarily short the power switch connector on the motherboard. Consult your motherboard manual to find which two pins connect to your case's power switch. Then touch both pins with a screwdriver to complete the circuit and boot the system.

If all is well, it should power up and you should get a display. Then assemble the parts into the case and try again. If the system now fails to boot, you have a short in the case and need to recheck your motherboard standoffs.

If the system does not boot after this process, then you most likely have a faulty component. You'll need to swap parts, start with the power supply, until you determine what is defective.


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## Tyree (May 10, 2009)

*Re: No Post. PSU?*



mrtacoma said:


> I guess I'll buy a new PSU.


If you purchase a new PSU, go with SeaSonic-XFX-Antec HCG for insured quality.
Note: Your CM PSU has a 5 yr. warranty so you could RMA it and sell the replacement or keep it for a spare for testing.


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## mrtacoma (Jan 17, 2014)

*Re: No Post. PSU?*

OK, I'm at a loss here.

I bought a new PSU. Plugged it in to the new motherboard outside of the case and the same thing happens. My only guess now is something in the case fried the board. I'm loosing my mind (and money) here.

So far I've replaced MoBo, CPU, RAM and now PSU and it still won't work. I am absolutely at a loss.


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## greenbrucelee (Apr 24, 2007)

*Re: No Post. PSU?*

the test with the RAM would have shown it was the motherboard plus the fact you are getting a single beep means everything is ok.

try a cmos reset.


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## Tyree (May 10, 2009)

*Re: No Post. PSU?*

See Post #5


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## mrtacoma (Jan 17, 2014)

*Re: No Post. PSU?*

Thank you Tyree.

I did follow your post. 

A new thing happened with the new PSU. 
Now I get a beep. The MOBO splash screen pops up and it goes black like before but now I'm getting three quick beeps when happens. Does that mean anything?

For the record I've swapped out 4 RAM sticks, two PSUs, two video cards and tried the on board video on the MOBO. I've reset the CMOS as we'll. All with the same result.


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## greenbrucelee (Apr 24, 2007)

*Re: No Post. PSU?*

if its long one beep and two short beeps then try cleaning the RAM, the slots and download memtest 86 burn to disc and run for seven passes on one stick at a time. FYI 7 passes can take 6 hours or more.


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## mrtacoma (Jan 17, 2014)

*Re: No Post. PSU?*

It's three quick beeps. This is after the regular beep when it starts and I see the splash screen. Three quick beeps as the screen goes dark.


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## oscer1 (Jan 27, 2010)

*Re: No Post. PSU?*

just little curiosity did the computer stay running after the 1 beep? if so have you tried another monitor?


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## mrtacoma (Jan 17, 2014)

*Re: No Post. PSU?*

Yes. The comp runs the whole time. I don't have another monitor to try but the splash screen shows up clear as day just for a second.


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## oscer1 (Jan 27, 2010)

*Re: No Post. PSU?*

whats the color of the power light on the monitor when screen goes out?


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## mrtacoma (Jan 17, 2014)

*Re: No Post. PSU?*

It stays solid blue. It'll blink if it's not getting a signal.


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## oscer1 (Jan 27, 2010)

*Re: No Post. PSU?*

then its getting a signal so i would be trying your monitor on another system or another one on yours.


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## mrtacoma (Jan 17, 2014)

*Re: No Post. PSU?*

I'm gonna feel dumb if I bought all that stuff and it was the monitor all along! I'll check it out. Thanks for the suggestion.


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## oscer1 (Jan 27, 2010)

*Re: No Post. PSU?*

your welcome. good luck


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## mrtacoma (Jan 17, 2014)

*Re: No Post. PSU?*

It was the monitor!!!!!

Thanks for all your help guys. I'm broke and I feel like an idiot but at least I have a working computer!


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## oscer1 (Jan 27, 2010)

*Re: No Post. PSU?*

thats great i would keep the power supply as a spare. your welcome.


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## Tyree (May 10, 2009)

Assuming at least one of the PSU's is good quality, use it and sell or keep the the other for a spare/testing.


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