A Stumper

[clocker]

OK.
This is really happening and no, I don't know why, so any thoughts would be appreciated.

Recently one of our original customers brought back his PC for an upgrade.
For sentimental reasons he wished to keep his case and he provided two 300GB Maxtor HDDs (still new in box) that he had gotten off eBay but we provided all the other parts.
-AMD 3200 Venice core CPU
-2x1GB Patriot RAM
-DFI LanParty UT nF4 Ultra-D motherboard
-CoolerMaster RS-450 PSU (his request)

Install/stress testing went without a hitch and he picked it up yesterday morning.
Within a half hour I got a phone call...PC wouldn't boot.
"Cannot find any bootable devices, please enter BIOS and set boot order" or some such nonsense. "Press F1 to continue or Del to enter setup".

He brings the machine back and sure enough, no HDDs are listed in BIOS...in fact, no IDE devices are detected at all.
How odd.
Replace cables, check molexes, power on the PC.
BIOS detects everything, boots right to desktop.
Reboot several times without an issue.
Unplug the PSU, let the machine sit for 5 minutes, power back on and...no IDE devices detected.
Enter BIOS (where no optical or HDD devices are shown), make NO changes, hit F10 and "yes" and all devices show up and PC boots normally.

Repeat, lather, rinse.
Basically, once mains power is removed, BIOS "forgets" all the IDE devices and has to rediscover them.
Date/time and all other settings are retained, it's only IDE that gets lost.
Test CMOS battery,which tests good, and replace it anyway.
Nada.

This is definitely a motherboard/BIOS issue (IMO) but I've never seen such a selective failure. I would expect ALL BIOS settings to be lost but they aren't...only the IDE devices go missing and they are rediscovered and work properly after the second reboot after opening BIOS (but making no changes).
As long as standby power is present (PC plugged in to wall) all is well.

What am I missing here?

[Mivaro]

I doubt it wil work, but did you update the bios? ( i know, it's a bit far fetched...)

[clocker]

Actually, yes.
When he first ordered the upgrade the customer had specced 1GB of RAM so we installed two 512 sticks.
He changed his mind midstream and wanted to up that to 2GB, but we couldn't get it to pass memtest with all four DIMM slots populated so we flashed to the latest BIOS hoping to solve the problem. It didn't, so we just got two 1GB modules instead.

It seems a relatively common issue BTW...nForce4 chipsets and 4x512 RAM doesn't work very well for lots of folks apparently- forums are full of plaintive cries for help over this issue. Sprocket never had any trouble so I was just lucky, I guess.

Not a bad idea though, Mivaro.

[fkdup74]

Have to ask this.....was the mobo forgetting the IDE channels before the BIOS flash?
Probably more far-fetchery, but..

[Virtualbody1234]

Fault in motherboard. Swap with another and test.


An afterthought: Perhaps the mobo is making contact with the case (shorting out)?

[clocker]

Have to ask this.....was the mobo forgetting the IDE channels before the BIOS flash?
Probably more far-fetchery, but..

Actually a very astute question and the short answer is...I don't know.
Although the PC was on the bench for three days as it went through assembly, troubleshooting the RAM issue and stress testing, it was probably never completely powered off. It was [i]shut down certainly, but the plug was never removed so there was always standby power to the board.

The new owner came to take delivery while the machine was still on the bench as we demonstrated the features, etc. ( and really we do this just to prove the damn things work when delivered).
It wasn't till he got it home that this issue arose.

It's actually quite easy to workaround and could be ignored but of course we can't suggest this so a solution must be found.

I suspect that VB's suggestion is the way we will have to go- just replace the board altogether.

It's odd though, isn't it?

[suprafreak6]

yeah, maybe its a pure faulty mobo and cant be fixed by manual labor

[peat moss]

yeah, maybe its a pure faulty mobo and cant be fixed by manual labor

Manual labour ? Our his twin General Electric . Funny was going to suggest Bios update but thought PSU ?

[lynx]

I've seen problems like this before, but only occasionally, not reproduceable on demand, and in each case the problem has been faulty hdd.

Since you are bound to have one or two lying around it would be easier to connect one up and see if the mobo remembers it, just to rule out that possibility.

[suprafreak6]

nice one lynx, i think you may be onto the solution