[SOLVED] Asus M5A99FX PRO R2.0 Flashback bios LED and power up issue

Feb 9, 2022
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PC is AMD FX 8320 CPU 8Gb RAM , Windows 10 64b

I have a Asus M5A99FX PRO R2.0 motherboard. PC has its flashback LED blinking five Long flashes and Two short flashes then repeats when the PC is off, the green power standby LED is lit. The only way to turn the PC on is to turn the power supply switch off and then at the same time hold down the power button on the front of the PC and turn the power supply switch back on ,the computer with then Boot OK.

The PC will reset and restart OK it’s just when the PC is completely powered down that this behavior occurs.

I have already cleared the RTC and replaced the bios battery, re-flashed the BIOS. I’ve never used the flashback utility and I have nothing plugged into the flashback USB port in the back of the PC. Other than having to use two different switches to turn the PC on it works fine. I have also tried disabling the flash back USB port.
Any ideas?
 

Darkbreeze

Retired Mod
Yeah, I was going to suggest ASUS support but I absolutely assumed from what I was seeing, or rather, wasn't seeing, that they probably wouldn't have any answers for you on this because I don't think it's intended behavior.

I think it's pretty likely the problem is simply that it's a rather old board, being 8-9 years old currently, and is starting to fail. It's really not too surprising. Average lifespan on most these consumer boards is anywhere from 5-7 years on average, especially if it's a system that's seen substantial use so at 8-9 years old it's no surprise if something on there is failing. I wouldn't think anything transient that might affect it in this way but anything is possible I suppose.

Have you tried removing the power button wiring to the board and jumper the pwr pins to see if it starts normally like that?

https://www.gamersnexus.net/guides/2011-jumping-a-motherboard-without-power-switch-button
 
Reactions: Bobakman

Darkbreeze

Retired Mod
Did it always do this or was it working normally and then just suddenly started doing this? Or did you just acquire these parts recently?

Did you make sure the time and date are correctly set in the BIOS after replacing the CMOS battery and clearing the RTC?

To be honest, I can't find any information on the Flashback LED located at the bottom of the motherboard, anywhere in the user manual or online, although I see it identified in the board diagram in the user manual, other than in reference to three flashes when done updating via Flashback. There doesn't seem to be any kind of intention of codes or any use for that LED other than during BIOS update operations. I suspect that if it is flashing irregularly, there is a problem with the board.

Might also be a problem on one of the rails of the power supply.

What is the exact model of your power supply and how long has it been in service?
 
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Reactions: Bobakman
Feb 9, 2022
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Thanks. The PS is a Corsair CX500 The PC was given to me Minus CPU and PS from my son he built another and did not need it so I use it for documents and scanning. The power supply was new old stock, I had it new unopened as a spare and it has been in service for about 12 months, all rail voltages are normal and I am not running any large component loads anywhere near 400 Watts. CMOS time and date OK it never did this prior to yesterday.
I was using the PC to update the firmware of one of my IP security cameras and was swapping the LAN cable from the camera to the router a few times while doing so, this was the task that was being performed.
After finishing the job I powered the PC down then later needing to use it pressed the power button on the front panel as usual and it would not start.
I took the case side panel off and saw the flashing green flashback LED.
Thinking of this now I realized that the flashback USB port is adjacent to the LAN port and the fact I was hot swapping the cables a transient could have occurred and damaged the board??
I chatted with Asus support and asked if there were any failure flash codes associated with the flashback LED and he had no answer same as the internet searches so far and with no known codes other than the flashing by design.


Bob
 
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Darkbreeze

Retired Mod
Yeah, I was going to suggest ASUS support but I absolutely assumed from what I was seeing, or rather, wasn't seeing, that they probably wouldn't have any answers for you on this because I don't think it's intended behavior.

I think it's pretty likely the problem is simply that it's a rather old board, being 8-9 years old currently, and is starting to fail. It's really not too surprising. Average lifespan on most these consumer boards is anywhere from 5-7 years on average, especially if it's a system that's seen substantial use so at 8-9 years old it's no surprise if something on there is failing. I wouldn't think anything transient that might affect it in this way but anything is possible I suppose.

Have you tried removing the power button wiring to the board and jumper the pwr pins to see if it starts normally like that?

https://www.gamersnexus.net/guides/2011-jumping-a-motherboard-without-power-switch-button
 
Reactions: Bobakman
Feb 9, 2022
3
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10
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Agree. Yep One of the first things I did being an electrician was as you stated jumping the pins and also verifying the continuity of the power switch.
Thanks for the input. Your questions and suggestions helped me to see things in a more focused manner.
This is a great forum thanks to folks like yourself.

Bob
 

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