Diagnosing cause of FF Post please. [SOLVED]


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I think this thread best goes in here. I am needing help diagnosing the cause of a FF Post error on my unRAID machine.


Specs are as follows...

 

unRAID : 6.4.0-rc9f on iGPU

 

Mobo : ASUS Maximus IX Formula (current BIOS, in warranty)

CPU : Intel i7 7700K (in warranty)

RAM : 2x16Gb Corsair Vengeance DDR4-3000 (in warranty)

GPU : Nvidia 780ti 3Gb (no warranty)

PSU : Corsair AX860i (unknown if in warranty)HDD : 4x WD Red 8Tb (in warranty)

Cache : Samsung 850PRO 512Gb (in warranty)

NVMe : Samsung 960PRO 1Tb (in warranty)

PCIe : Asus Hyper M.2 Mini x4 (in warranty)

PCIe : Inateck USB 3.0 x5e/x2i

 

Symptom : POST is successful all the way till unRAID presents its boot/boot with GUI, safe boot, safe boot with GUI, memtest screen. I can hold it there and it is all fine.

 

The INSTANT I select any unRAID boot option (even safe mode) the motherboard immediately flips to FF. There are no warning LEDs on the motherboard anywhere.

 

unRAID continues to load for about 30 seconds, usually reaching the root login. There is GUI activity over the LAN if watched from the iPad. After about 30s, the PC will simply shut down.

 

Things I have tried : pull all PCIe cards, all HDD/SSD/NVMe devices - no change. Try RAM one stick at a time - no change. Reset BIOS to defaults - no change.

 

What I am about to try : remove all water-cooling and re-fit air coolers to CPU and GPU so I can pull the GPU and run it off the iGPU only.

 

What is it that unRAID does within a second of passing the blue unRAID BOOT screen?

 

EDIT : I forgot to mention, I tried a different USB stick with trial license and it had no effect.

Edited by DanielCoffey
Resolved - faulty power
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POST is the hardware bootstrap sequence.  Once you've posted, your machine will access boot devices and try to load an OS - which it sounds like it's doing if you're seeing the unRAID screen.  My understanding is that FF is normal "Fully Functioning" after the post code sequence.  I could be wrong, I don't have a motherboard with that display... but it leads to a quick question:

 

Have you tried booting another OS other than unRAID?  Or a prior version of unRAID with legacy boot?

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On the consumer boards, FF is usually an error code. A0 is most often the "everything is normal A-Ok" code.

 

I don't have a bootable disk yet but I will when I have stripped the machine down. The issue has appeared suddenly. Last night I had one unexpected shutdown. I got another this morning then this afternoon it became constant on every boot.

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Right - I checked the pumps and they were fine. Flow was suitable but I cranked them up and blew a load of old bubbles out of the tubes at the same time. No change in POST codes.

 

I did notice that it sat on A9 while on the unRAID boot choice screen then the instant I selected normal boot it flicked very briefly to F6 then changed to FF and sat there.

 

I have now drained and stripped the machine to the bare parts and will swap the CPU water block for a generic air cooler tomorrow when it arrives. I have a spare GPU now as well (1050ti) so apart from the PSU (which self-tests OK), there is nothing left that I can replace. I will set my working unRAID USB aside and use the trial USB stick I have just set up.

 

If I get the FF code with the bare board, CPU, one memory stick and iGPU then I will briefly set up a bootable WIn10 or Linux install on a spare SSD and see if it does it with that. I may have to buy a PSU tester too. After that if I still get the FF then I can talk to Scan in the UK to start any appropriate RMA process.

 

If I pass the barebones boot, I will add in the second memory and the 1050ti and see how we go.

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OK, I am now a step closer to working out what my hardware issue is.

 

PSU self-tests green.

PSU cables 20-pin and 8-pin to motherboard

CPU air cooler fitted and fan connected to CPU_FAN

One RAM stick in DIMM_A2 (as advised by manual)

Power/Reset buttons and HDD_LED/PWR_LED to motherboard header

 

The first time I turned it on, the CPU fan spun normally. I got all the way to the BIOS, reset to defaults and allowed the machine to boot. I got all the way to the unRAID boot choice screen without issue. I selected the normal unRAID boot option and it seemed that the early stages of an unRAID boot were proceeding (about ten seconds) and then something failed with the hardware. The POST LED flickered and alternated between 00 and 04. The CPU fan changed speed and "fluttered" unevenly in speed. I powered off.

 

Now, despite clearing CMOS and removing the battery the machine fails POST immediately on power on. I get 00 then it alternates rapidly to 04 "PCH initialisation before microcode loading" and back to 00. The CPU fan "flutters" in speed and the motherboard red CPU error LED lights and flickers rapidly.

 

Normally the CPU error LED would point to the CPU but the 04 PCH points to the motherboard.

 

What do you think?

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Finally resolved...ish.

 

@tdallen - you were right about FF being Finished Fine because it was legacy boot mode. If I boot to an UEFI device such as an SSD I get A0. If I boot to the unRAID Legacy USB stick I get FF. Every time.

 

However... the random reboots and 00/04 flickering were a serious issue that I have managed to (almost) isolate. It was the delivery of power to the motherboard, particularly to the 8-pin CPU power header.

 

I bought a very cheap refurb Corsair PSU from Scan and attached it and noticed the ROG LEDs on the PCIe slots flickering madly as soon as the PSU was connected but before the board was switched on. Reseating the PSU cables resolved it and regardless of whether I used the old PSU or the refurb new one, the board then booted cleanly every time. I did then manage to reproduce the LED flickering when fiddling with the PSU cables on the old PSU. The 8-pin cable is really touchy. I don't know yet if it is a loose connector in the cable, in the PSU (but it does not seem to be limited to one PCIe 8-pin output (PSU is modular) or if it is the motherboard 8-pin header. When I have a bit more brain in the next day or so I will spend more time examining it.

 

In preparation for a future upgrade to Xeon and twin-GPU I have ordered a new high capacity PSU which will arrive on Wednesday. I will try the board with all new cables and the new PSU. If the PCIe ROG LEDs flicker then, I have proved it is the motherboard and Scan have confirmed they will accept it back.

 

No sleep because of the UK gales last night and my brain hurts! I did manage to install a Noctua DH15 cooler though - that thing is huge!

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