What's the diagnosis?!

Shan21

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We did a new PC build in July 2011:

Asus P8P67 mbd
i5 2500
4Gb (2x2Gb) Corsair XMS 1600 DDR3 initially, then in Nov we got another kit (exactly the same) so the system now totals 8Gb.
500W Corsair CX500 PSU
DVD-RW
and Lian Li tower for good cooling, quiet fans and rust-proof aluminium!

+ previously owned:
Nvidia 8500GT GFX card
Seagate 7200rpm HDD's - 500Gb + 160Gb +160Gb.

Mainly used as home admin pc - email / internet etc. but also used for video editing and audio applications.

Initially everything worked great, except that the RAM registered in the BIOS as 1333mhz instead of 1600.
We left it alone, but then one time it restarted itself and brought up a window about "overclocking has failed" - we don't OC??! So I went into the BIOS and with the mbd manual set it up to be as normal as possible (disabled the turbo feature etc). At this time I put the Ram into the XMP mode so as to run at the spec'd 1600.

From about september we started having:
- a whole lot more of those restarts mid- whatever-we-may-be-doing, and then the "american megatrends - Overclock failed" page. Go to the BIOS (don't change anything) but click save & restart and it boots up fine.

- then "outs" of our visuals instead of the OC fail restart.
Just randomly, whilst working or surfing the net or even on idle, the PC screen goes a solid colour and there's nothing we could do. The colour it goes is just as random as the times it happens! We are forced to restart, at which point everything returns to normal - we just have to choose "start windows normally" because of the bad shutdown.

- Some days we had no problems, others we may have had 3-4 episodes through the day.

- Sometimes the GFX card was (and is) extremely noisy

so we wrote to our supplier.

He thought it was the mbd, so we shipped it back up to the distributors for testing & RMA. They found the unit to be unstable and flashed the BIOS and installed a new one. Then sent it back to us.... 14 days and a few turned-away jobs later! Meanwhile our supplier ran our PSU in his test rig to check it out - he didn't notice any problems there.

It seemed to be fixed!!

Then about 2 weeks after having it back...
- it started with straight freezing
- then the random screen colours came back with the need to force restart.
- then it switched off completely, just off... like there’d been a power failure – only the little green light on the MBD was still on. It would not switch on again, we had to flick the PSU power button off & leave it a while before rebooting.

- Ran it in safe mode and just to be sure ran all the virus & malware software with no result. Then we booted into our regular system without incident.

- We downloaded & ran Memtest86.
The first time we ran it (testing one stick at a time) we ran into some errors. The pair of the stick with errors we left out & rebooted, but the freezing happened again a while later. Ran the memtest again, and though we did not get to testing every stick in every slot, we did test every stick & slot at least twice. The errors we got before were not repeated. On some sticks / stick-slot combos? the memtest screen filled with odd symbols (see pic
550957_10150857545310303_598637051_n.jpg
) somewhere between the 3rd and 5th pass, although each time the test pass completed, the line saying “No Error detected...” came up in the middle of the screen of symbols.

- We’ve been monitoring temps and have not had any issues on that front.

The issues aren’t happening with anywhere near the same regularity that they were before the RMA. But they are happening, and most often the issues come with either no load or very light load – like when its sitting idle or when opening a solitaire game or a basic webpage or checking/reading email! Only twice or three times since getting the PC has one of the described issues happened while doing video/audio work, watching a dvd or downloading a large file from the net.


The latest auto-restart has triggered the following BIOS msg: “ASUS Anti-surge triggered to protect system from unstable power supply unit”. and I noticed that it’s reading the 1600 Ram as 1333 again... tried to change it back to 1600 but it wouldn’t budge so left it alone. The next time that same restart & error happened it was back showing 1600??!

Redid memtest last night - no errors found but loads of wierd symbols....

What is wrong with this setup????








 
Try another psu if you have one otherwise I would take out as much devices from the computer as possible and run it like that to see if it happens again (like using the onboard display if you have one instead of the display card etc.)

Wish I could tell you more but I'm not an expert.

And I'm guessing that the bios resetting itself is just a symptom of the actual problem (like the mobo trying to recover from something)
 
Thanks for the reply!

Unfortunately don't have another psu... can try disconnecting the 2 extra HDD's, but not sure that would give me any definative answers... it may indicate the PSU is taking strain if the symptoms resolve?

Oh yes... one more weird thing - the last 3 shut-downs:
- the screen goes blank and the monitor light starts flashing (like there's no signal),
- the power on light on the tower remains "on"
- the blue light of the case fan remains "on"
- all the fans (cpu/case etc) remain "on"
- No HDD access light
- DVD tray will not access.

ie. it acts exactly like a fully shut-down PC... only all the lights and fans are still going!!???!!

WTH??
 
My guess? Memory.
Swap the modules out.
I've also had cases where memtest does that, sometimes the memory test was fine, sometimes it wasn't. Ended up using just one 4GB DIMM and all has been well for at least 1.5 years.
Memory issues can really f*** with your logic :)
 
Last edited:
You say the GPU is loud?
fan possibly not working properly and GPU overheating?
 
Thanks for the input RaptorSA.

@AstroTurf - yes the GPU is loud a lot of the time. Somedays it's really quiet!! Even with the most intense video work (effects etc) and other times it's like a badly tuned rally car with shocking gear changes... when the pc is on idle!

no hot temps registering though
 
will do.

Has been stable for a few days... won't mess with it til I've got my work out of the way :)
 
Hey Guys,

Thanks for the input, sorry I haven't updated - shortly after my last post the PC died and it took a month of testing by our supplier & his distributer to determine the actual cause....

Turns out it was the PSU all along! Got a new one and everything has been hunky dory since :) but what a palava to get to the bottom of it. So much for our supplier's original tests on the PSU....
 
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