Help me diagnose this HW prob?

[joshogden]

Hi all,

Asus P5Q Pro mobo, 4gig (2x2) corsair DDR2-400, Intel E8400 Wolfdale @3 GHz. Win XP SP3

Back story:

Recently had a video card fail (some Chinese-made 8600gt). It caused a lot of BSODs and failed boots before I finally gave up and yanked it.

Replaced faulty VGA card with a new HIS HD5670 (bought 2 intending to use Crossfire, but only installed one so far).

System was completely FUBARed when I got it back into Windows (the C: drive had been badly corrupted, causing registry errors etc.) Restarted and ran checkdisk in raw mode, twice. It seemed to have repaired the drive (files became usable again.) Ran CCleaner on the registry. Then went on to remove old nVidia drivers and prepare to install Catalyst. Could not get installers to run, plus other probs. System was still so screwed up I decided to just wipe it clean and start from scratch.

SO, after formatting SLOW and loading up a BRAND NEW Windows installation (with no service packs or drivers installed), I still get multiple errors (intermittently) on startup:

"Instruction at referenced memory could not be read"
"One of the files containing the system registry data had to be recovered by use of a log or alternative copy."

This along with other unpredictable behavior... (in one case I boot up and explorer just instantly crashes every time I click the start menu)...

I THOUGHT the one or both of the RAM modules had gone bad, but Memtest86 turned up no errors.

I am stuck at the office right now and have no access to my machine for further testing. But my next theory is lack of power with the new VGA card. I cannot remember off the top of my head what kind of PSU I have but it is cheap and probably 550-650W.

The last time I booted, before I left this morning, I got NO errors and everything seemed to be working fine. This bothers me because I like to know what is wrong. I have no reason to believe it will remain this stable.

I am not looking for specific answers, just thoughts and ideas to help jog my brain in the right direction. Is there anything I'm not considering, or do you have some suggestions for how I can better diagnose this issue? I just need to know what to replace, and I hope it's not gonna have to be the mobo...

Thanks for reading!

 

[joshogden]

so after you ran memtest the problem hasn't come back yet.?

I only had time to boot once after the test, then I had to leave for work. That ONE TIME, it seemed ok, but the symptoms have been so wild and unpredictable I don't think this means much. I bet if I boot 10 more times I will see the errors.

I didn't change anything, just ran a memtest, so I don't understand why it would suddenly be working...

I can't WAIT to get back home and try again, then I can let you know.

2.5 hours to go....

 

[joshogden]

Hi Malmental, thanks for ur help.

I am home now, the machine is booting clean and showing NO SIGNS of problems. It is not a genuine copy of windows. I switched out the RAM yesterday, trying one at a time, and then both, so they've been reseated. My next step was actually going to be looking at the BIOS, which did get reset when I cut the power to the board, so I will get back to you with my findings. I have read that sometimes this can be caused by an incorrect bios setting.

I also wondered if it could be an improperly seated VGA card, since the metal tab is right up against the inside of the case. But it looks parallel, so IDK. Again, I'm kind of afraid to mess with anything now that it appears to be working...

Right now I am installing the chipset drivers and SP3 and all that good stuff. I will report back soon with more info, if I come up with anything.

I hate it when problems inexplicably fix themselves...

Thanks again.

 

[joshogden]

reset bios again. Used CPU-Z to check memory timings and look at this...

#1:
Freq: 270 MHz
Timings: 4-4-4-13-15

#2
Freq:400 MHz
Timings: 5-5-5-18-22

I am a RAM noob. Aren't these supposed to be the same? I have a matched pair of Corsairs. Is it normal for my bios to be setting asymmetrical values?

 

[joshogden]

Ok i now understand that #1 and #2 are channels and not slots

so the two modules are matched, but the channels are not. False alarm.

 

[joshogden]

Sry I misspake. I should not have said channels. But 1 and 2 are def not slots. The slots are listed elsewhere in the CPUz interface, in a dropdown menu, and when I toggle through them (I have four) I can see which 2 are used. The timings are the same. Non-issue.

I could not find any reference or setting for single/dual channel in BIOS.

I haven't had any more probs at all, even got to test out the new VGA card a little bit. Definitely a massive improvement, even without crossfire.

I may have accidentally dislodged and reseated some component... I don't even know anymore. Thanks again for your help. I think we should consider this topic closed unless I start seeing the errors again. I am just thankful to have a smoothly running machine. Sorry for being a tard and wasting ur time!

Peace