Bad Axe won't post with 4 gigs of RAM

[bildo17]

My Intel 975xbx (rev. 304) will accept three 1 GB sticks of Corasair XMS memory, but when I put a fourth stick in, I get the three beeps and it won't post. I have tried all four sticks in different combinations, so it isn't a particular module that is "bad". I followed the voltage settings recommended by Corsair and have tried altering them, but I can't get all four to work at the same time. They were all purchased together, by the way. I can't find anything on Intel's site or Corsair's sited about a known problem. Any help would be appreciated.

Thanks,

Bill

Core 2 Extreme Processor 2.93
MSI 7950 gxt Video card
Vista Ultimate 64 bit

 

[chungdokwan]

Maybe its a obvious question but are you running the latest BIOS version ?

 

[bildo17]

Yes.

 

[XMSYellowbeard]

Have you tried raising the NBv at all? And, what PSU do you have?

 

[Tegrat]

Did you have your RAM timings set manually before the upgrade? 1T? 2T?
Is it set for SPD (Auto detect)?
I would try and relax the timings a little with 2 sticks in and see if it works when you add the 4 back in...

 

[dolynick]

Try reducing the speed of the ram. If its DDR800, try setting it to 667MHz. Many motherboards apparently have difficulty running 4 sticks at full speed.

My Striker Extreme will BSOD with 4 XMS2 modules at 800, but runs just fine with them set at 711MHz.

-dolynick

 

[bildo17]

The memory is Corsair XMS DDR2 675 (C5400) with timings of 4, 4, 4, 12. The mobo (when set to automatic) runs it at 5, 5, 5, 15.

I have tried running at 533 (three beeps, no post), 800 (three beeps, no post), and 667 (no beeps, but no post).

I have also tried voltages of 1.9, 2.1, 2.2 and automatic. At 1.9 and 1.8 I get three beeps, no post.

I'm open to suggestion.

Thanks for all your replies so far.

Bill

 

[Tegrat]

Recap:
- All 4 sticks work? MEM-tested in pairs? - possible bad stick
- Work in all combinations in the slots |||0 ||0| |0|| 0|||? - dirt or small hair in MEM socket pin - Don't laugh, seen it more than once.
- different FSB speeds and different timings. (Auto) - compatiblity issue.
- Nothing else added to the system at the same time, ie flash drive etc...? - external source causing issue.

Ditch effort:

Do you have an after market cooler on your CPU or some other foreign device attached to your motherboard in close proximity to the MEM modules?