A8N-SLI Premium - Still Won't Post - What Next?

Staff-Tech

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Here's my stuff:

ASUS A8N SLI Premium / Qty 1 ASUS 7800GTX TOP / AMD x2 4800+ / Cucial Ballistic 2 gig kit / Qty 2 SATA WD Caviar 250 16mb / Antec Truepower 2 550W / Antec P180 case / Dual Samsung 940b 19" LCDs

The system will only post 1 of 3 times requiring multiple resets to finally get the one beep and boot. When it does boot in often freezes up at the windows log on, or after log on. When it does run it runs good until I try a game - then it freezes as soon as the 3D action starts and must be reset.

When the system is running temps never reach 40C and voltages are all within range of norm. I've performed every conceivable combination of hardware trouble shooting including disconnecting all components one by one, removing and swapping single ram modules, RMA'd video card with new on, and RMA'd power supply with new one. I ran the mobo alone, out of the case as well with just Proc, RAM and video card. Same failure to post - black screen, no beeps.

I updated chipset drivers. I started with BIOS V 1007, updated to 1009 and even tried 1011 beta. I've played with a wide range of different BIOS settings

The only thing that seemed to make a difference is the second PSU allowed 3dMark to run a while before it froze. So I'm just guessing that a different, slightly larger (more stable) supply might help. There's a few guys on the Asus forum that had similar posting problems and claim that a move from the Anten PSU to the Seasonic did the trick for them.

I'm out of ideas and my only remaining options are to RMA/Upgrade the PSU, then RMA the mobo for same, then RMA mobo for different one (not sure which).

Any tips of suggestions on my next move would be appreciated.
Thank you,
Barb

UPDATE: SEE POST BELOW
 

Staff-Tech

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Thanks for the tip. Crucial states that the voltage for these proms are 2.6V. Though I did try to crank them to 2.65 and 2.7. No change at 2.65 and strange boot failure at 2.7.
 

Staff-Tech

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UPDATE: On a tip I changed the hypertransport setting from Auto to 4X and the system has been fine since. I wonder though why with my HW specs I can't run at 5X which produces the same problems as Auto gave me (I assume auto was selecting 5X).
 

Flakes

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UPDATE: On a tip I changed the hypertransport setting from Auto to 4X and the system has been fine since. I wonder though why with my HW specs I can't run at 5X which produces the same problems as Auto gave me (I assume auto was selecting 5X).

probs just the fsb being to high, the HT needs to be at around 1000 to get to that it uses the fsb * HT so 200 * 5 = 1000, if you go above 1000 you may start to have stability issues. (doesnt help you but its interesting nonetheless :) )
 

pat

Expert
UPDATE: On a tip I changed the hypertransport setting from Auto to 4X and the system has been fine since. I wonder though why with my HW specs I can't run at 5X which produces the same problems as Auto gave me (I assume auto was selecting 5X).

probs just the fsb being to high, the HT needs to be at around 1000 to get to that it uses the fsb * HT so 200 * 5 = 1000, if you go above 1000 you may start to have stability issues. (doesnt help you but its interesting nonetheless :) )

No mention of his FSB here, but stock FSB can cause this behaviour with bad voltage regulation or undervolting on bus. The PSU might not be able to alway deliver stable power, making the reg to work harder and causing stability problem.

While old Antec were good, they now seem to be under par. I don't trust them anymore..

Even at 3x, there will not be any major performance loss.. The HT bus simply has enough bandwidth.. But sure, bigger number are selling better..
 

Staff-Tech

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Thanks guys- I must admit I'm a bit ignorant when it comes to these multipliers and settings. I understand that it's a bit of a balancing act between settings but never really read anything that spelled it out in terms of which are the important things vs just bragging rights. I once used a program for the ATI video cards that would automatically tweak various settings gradually until you saw artifacts, then it would throttle back a notch to a stable setting. Anything like that for processor/memory timings/etc?