faulty asus motherboard

[Harveyweewax]

I own an Asus P5GC-MX/1333 motherboard It has always worked perfectly but recently when I turned it on there was no video. I’ve been using the onboard graphics card. There is no speaker on the computer casing but the onboard soundcard usually emits a beep as it boots. This isn’t happening either. I don’t have access to a spare graphics card at the moment (I’m on a cruise ship in the tropics.)
The case fan and the CPU fan turns when I turn it on and the small green led on the motherboard itself stays on.
I’ve tried removing the memory chips and also resetting the bios to default but no luck.
Does anyone know what this could be?

[Konrad]

Welcome to TBCS, Harvey

Some other possibilities which probably do not (but might) apply here The ambient temperature is high enough to prevent the computer from sustaining operation. Alternately, the processor (and possibly mobo components like the GMCH/Northbridge chip or VRM caps) are not properly cooled; they could have bad heatsink mounts, insufficient thermal grease, or unpowered fans.
The motherboard BIOS (or an integrated TPM/encryption module) might have security settings which are halting the system until a pre-boot password or the presence of a dongle or some other unique/authorized hardware device is detected.
Some other hardware BIOS (adapter card, etc) is halting the system, probably due to incompatibility.
The motherboard or processor hardware has somehow seriously failed; blown cap, fried GMCH chip, cracked oscillator, damaged PCB traces, whatever.
The system disk (HDD) cables or jumpers are misconfigured, or it could be dying/dead or password-locked.
The OS is somehow damaged/corrupt or otherwise unable to boot.
My first guess is that the BIOS is configured to display adapter card instead of integrated graphics. Or it might have some other bad settings which prevent startup. You can try to reset the BIOS again; it may require one or two restarts to "take", it might require many restarts before it decides to autodefault to correct configuration errors after repeated failures, it may require a Clear CMOS jumper, it may require battery removal (for a few minutes; although dedicated capacitors might still power CMOS/NVRAM for hours or days if they are present). You should read the mobo manual. You might be able to obtain an emergency BIOS setup or flash tool from the mobo maker's site, though it could actually make things worse and so should be used only as a last resort once all other possible hardware failures have been ruled out.

Still, it is sometimes impossible to correct this problem without temporarily using a graphics card, unless you want to guess blindly (not a good idea with BIOS settings) because the "last good configuration" SMBIOS data could be stored in nonvolatile flash. A possible workaround might be swapping the system disk, forcing the SMBIOS-aware OS (that is, an OS which works in a different machine) to autodetect and reconfigure SMBIOS data for this "changed" hardware platform. This would at least allow you to boot and make BIOS changes. Maybe.

You've already tried removing the memory ... all but one stick, good RAM, in bank 0, I assume. RAM problems would've been my next guess.

Your mobo LED shows your PSU is sending PWR_OK and 5V_SB ... your PSU might still be failing under load, but all you can really do here is reduce power requirements to the minimum (remove all noncritical hardware cards, drives, extra fans, lights, USB devices, etc; essentially keep only the mobo, RAM, processor, system drive, keyboard/mouse, and required cooling) and maybe backprobe with a meter during operation if necessary. Assuming you don't have another sufficiently rated PSU to swap in.

Attaching a speaker might reveal system error beep codes you currently can't hear. Any little 8-ohm speaker will do, if you can cannibalize one from another computer or some other appliance.

The processor might not be properly mounted, but I would personally wait to try out a graphics card (and/or PSU) before reseating the processor unnecessarily. I doubt you have much thermal grease available on your ship.

[Luke122]

Thanks Konrad for all those tips! I was going to suggest reseating the CPU for testing, but you are right.. there maybe a shortage of thermal paste onboard. :)

PSU gets my vote for likely failure, unless there were previous issues leading up to the current situation.

[mDust]

I...uh...wow! Nice job Konrad! +rep from me for all of that...:D

[Konrad]

Just don't tell anyone my secret identity. See How He Uses A Spanner!
U01xasUtlvw

[Konrad]

An afterthought.

You could try replacing your mobo battery. It's a 3V CR2032 coin cell, available 2/$1 at your local dollar store.

[x88x]

One thing I would add to Konrad's suggestions:

Disconnect everything except for the CPU, MBB, and PSU, then pull the CMOS battery to hard-reset the BIOS, replace the battery, and see what happens. Since you're using onboard video, these three components are all that are required to post (well, that and the monitor, obviously; you'll also want to keep a keyboard hooked up). I've had a few times where a HDD has caused strange behavior like this. ..or, for example, my current MBB, if I have anything at all plugged into two of my 6 SATA ports (even just an eSATA extension), the add-in GPU doesn't work...I have no clue why, but I only have 3 SATA devices anyways, so it's not a problem for me.

Did anything unusual happen before it stopped working? Any new hardware, power blackouts or surges, environmental changes, etc?

[Konrad]

"environmental changes" could include "on a cruise ship in the tropics" ... hot + humid = terribly uncomfortable for consumer-grade semiconductors, ergo my suspicion the PSU is a bit wobbly until it gets back on dry land.

Sounds like it would've been a job for some conformal sealant. Too late for that now.

Maybe throw some of those toxic little dessicant pouches (or a box of baking soda, heh) inside the computer for a while, try to dehumidify it?

[x88x]

"environmental changes" could include "on a cruise ship in the tropics"


(I’m on a cruise ship in the tropics.)

Doh! I completely missed that.. :facepalm: ...that makes your insistence that it has something to do with heat and humidity make sooo much more sense. :P In that case, yeah, I'm with you on that.

[Konrad]

8 useful responses from 4 technicians in just a few hours ... how come my tech support never works like that?

[Luke122]

TBCS = Awesome.

[x88x]

TBCS == Awesome.

FTFY ;)

TBCS is not merely designated to represent or point towards awesomeness, it is awesomeness. :D

[Konrad]

Aha ... yet another afterthought.

Perhaps the shipboard power source isn't very clean, especially if some kind of bizarre international receptacle adapter gizmo is used?

[x88x]

Ah, I didn't even think of that...if your PSU has a 120/240V switch, make sure it's in the correct position for the line you're plugged into. Though, if you were feeding a 240V line into it set to 120V, you should have seen the magic smoke...

[Konrad]

lol, for all we know, Harvey comes from Japan or Brazil or someplace where 240V is the norm. Switching 120/240V and 50/60Hz allows for 4 possible combinations, 3 of which will smoke or labotomize your machine.