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Old 07-29-2021, 02:46 AM   #1
pfrcom
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Default Asus P8Z68-V/Gen3, after saving UEFI settings, shuts down, doesn't restart

I've tried all BIOSes available to download, most recently first release version 0301, using an i3-2100

For each try, after externally reprogramming its Winbond 25Q64BV (DIP8) with TL866IIplus

Always same outcome - after Save & Exit, board shuts down and doesn't restart

If I press onboard Power button, it'll start up then shut down again

After jumpering CMOS Clear, it'll start to UEFI settings then repeat same behaviour

It's had a new CR2032 fitted

Closer examination found a second flash IC, a soldered Pm25LD512 (SOP8 or SOIC8, whichever is smaller), just to left of SATA connectors block (25Q64BV is on right)

In these days of Management Engine and multi-MB firmware, something 64KB seemed too small to be relevant, but having run out of ideas, I desoldered it to see what would happen

After power on, board contemplates for a few seconds, flashes a couple of red LEDs, bleeps with a brief glimpse of Asus logo, messages "The data in the EC or EC flash might be corrupted", then shuts down

Dump of Pm25LD512 is attached - BIOSes tried are the *.ROMs downloaded from Asus

Could anyone advise/assist please
Attached Files
File Type: zip PM25LD512orig.zip (23.2 KB, 1 views)
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Old 07-29-2021, 01:18 PM   #2
SMDFlea
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Default Re: Asus P8Z68-V/Gen3, after saving UEFI settings, shuts down, doesn't restart

Its the EPU firmware.I checked it against one extracted from the asus bios and its exactly the same.Flash it back and carry on troubleshooting .
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Old 07-29-2021, 07:19 PM   #3
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Default Re: Asus P8Z68-V/Gen3, after saving UEFI settings, shuts down, doesn't restart

Quote:
Originally Posted by SMDFlea View Post
Its the EPU firmware.
Thanks for checking, and for the feedback

Unfortunately I've run out of ideas, so scrapping the P.O.S. is looking like the most feasible option

If EPU firmware is in the BIOS, I can't understand why there'd be a second, dedicated, flash IC just for it

Maybe the Pm25LD512 is acting as a scratch pad and getting rewritten every boot, so replacing it perhaps worth a try
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Old 07-30-2021, 04:46 PM   #4
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Default Re: Asus P8Z68-V/Gen3, after saving UEFI settings, shuts down, doesn't restart

Do you have a POST card
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Old 07-30-2021, 08:35 PM   #5
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Default Re: Asus P8Z68-V/Gen3, after saving UEFI settings, shuts down, doesn't restart

Is "EC" for "embedded controller"? (Is it the same thing as "KBC" on a laptop?) (even when an ATX motherboard?)
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Old 08-02-2021, 06:47 PM   #6
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Default Re: Asus P8Z68-V/Gen3, after saving UEFI settings, shuts down, doesn't restart

Quote:
Originally Posted by SMDFlea View Post
Do you have a POST card
Yes, and it's about as helpful as usual - which is to say, not very much

After powering-on motherboard once it's failed to restart, the POST card shows something like "finding type of keyboard and setting Numlock status" before losing power again
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