Intermittent POST with ASUS M4A78T-E, will POST after pulling plug

john5246

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Mar 13, 2010
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To begin, I am not new here, but been away for a while (haven't had any issues :) I read the sticky
http://www.tomshardware.com/forum/261145-31-perform-steps-posting-post-boot-video-problems

My problem is with my ASUS M4A78T-E motherboard and an intermittent POST (Power on Self Test). I am posting this topic from the affected computer in Windows 8.1. Which means it POSTED (power on self test) and booted into Windows 8.1.

When I shut down the computer from Windows. It will not POST again. To make it POST and boot into windows I must:

1. Turn off the power from the PSU (power supply unit), it has a switch with a -/o
2. Wait for the green light on the Motherboard to turn off
3. Turn on the switch from the PSU
4. Wait till the green motherboard light turns on indicating power

5. Press the power button on the front of the computer
6. BIOS screen shows CMOS battery Low F1 for setup F2 to load default values and continue
7. Hit F2 and Windows will load



Specs:

AMD Phenom II 955BE 3.2Ghz
ASUS M4A78T-E (stock BIOS)
Corsair 8GB (2 x 4GB)
Integrated graphics


Other info:

I tried this with 2 separate PSU's and it does the same thing. I removed the MOBO from one case and put it in another, the CPU was never removed, just cleaned and used a different cooler. The RAM is the original RAM I've been using with it for 5years. Basically the only thing that's been done to the system is that I removed the graphics card (AMD 7970) to use in a new build and want to use this system with it's on board graphics.


What could be the problem?
 
I restarted Windows 8.1 and the system would not boot again it just hangs. I cut the power from the PSU, windows attempted to boot but got BSOD (blue screen), shut off power again from PSU and second time windows booted.

Troubleshooting so far:

1. Recreated the problem using two separate PSU's, this likely indicates that the PSU is not the problem

2. Cleared CMOS according to ASUS's instructions in the manual, removing the jumper from 1-2 and placing on 2-3 then moving it back to 1-2 (please see manual for instructions you can download the manual for your motherboard from the vendor's website)

_______________________

Removed all components from the case and proceeded with Bench test:

Only 6 components are attached
CPU
Motherboard
RAM (1 stick)
Hard Drive
USB Mouse/Keyboard
Power Supply
(oh and speaker to hear the POST beep)

Since the problem exists with both the Power Supplies we can cross that off. Next step was to run memtest86 from a flash drive to test the memory. All checked out so we can cross that off our list, also tested with secondary memory stick in the first slot.

I removed the USB Mouse & Keyboard, same POST problems, we can eliminate that as well as a likely cause of the problem.

That leaves 3 things:

Hard Drive
Motherboard
CPU

Since I have 4 hard drives and I tested each with the same problem, we can eliminate that.

Now it's between two critical components, either the CPU is bad or the motherboard is bad. If I was a betting man I would say it's the motherboard.

At this point I have nothing to lose anyway, I decided I'd see if there was a problem with the BIOS...I don't know maybe they got corrupted somehow. I downloaded the latest BIOS from ASUS and transferred the ROM file to at USB formatted in FAT32 (will not work in NTFS). I successfully updated the BIOS using ASUS Easy 2 Flash utility.

And the problem persists, so it wasn't the BIOS, some other component on the Motherboard is ruined, this is where I need help from someone with more experience

[strike]I wish someone could tell me to just replace the CMOS battery and that would fix everything, is it really that simple? Why did that message start showing up that the CMOS battery is low?[/strike]


Replaced CMOS battery and it's still showing CMOS battery low, this did not solve any of my issues.

Thank you to anyone that has read this, I have used the process of elimination to help narrow down the problem, and the price of a better board than the 8yr old M4A78T-e is only $50. Any help or suggestions are appreciated.


BTW I am posting all this from the affected computer, it's will boot when power is fully shut off from the PSU, but will not restart or power up after shutdown (from windows), you must cut the power and even with that it's a 50/50 chance, if windows 8 goes into the start up repair utility you can forget it. As long as windows doesn't enter that start up repair it will usually load.