PC will only boot with less than 4 out of 4 DIMM slots used

[MrNova]

Two days ago my system began randomly crashing/blue screening after months of no problems. The blue-screen errors were different all the time. It started doing this sooner and sooner after booting, and eventually I could not get past the BIOS splash screen. After troubleshooting I realized that the system would only work if I removed 1 of my 4 memory DIMMs.

All four modules are identical (4-4-4-12 timing with 1.9-2.3v rating). I memtest86 checked each DIMM individually, and in dual/single channel pairs, no problems with the RAM detected. I've also swapped using each DIMM slot with every combination of DIMMs and they all work when 3 or less are inserted. As soon as a 4th module is inserted, the computer fails to boot.

Now when I try 4 I do not even get to the splash screen; the fans spin and the hard drives spin up but nothing happens.

I've flashed to newest BIOS and I?ve also tried altering the BIOS settings. I have tried increasing the MCH and DDR voltage, and I have tried decreasing the timing, but this doesn?t help. I have also tried to boot without any drives connected to see if there was a problem with the power supply, but it did not help. This motherboard is less than a year old.

With less than 4 DIMMs the system is totally stable like it used to be.

Any suggestions before I go through the ordeal of swapping a motherboard?

 

[krnmastersgt]

Errr, are these 4 1gb sticks? It'd be less stressful on your northbridge if you just bought 2 2gb sticks, should give you a slightly higher overclock if you ever planned on making that a serious idea.

 

[MrNova]

Yeah, but then what do I do with the 1gb sticks? Im a cheap bastard, it's really the principle of it

 

[Blazer]

its been my exp that consumer based mobo's donot like all there slots filled, some have success and some dont, raising the memory voltage will sometimes help but at the cost of early MCH/Mobo failure, on another note having four sticks that are alike doesnt make them a matched pair, if you need 4gb then you may want to use 2X2, or you may not, damage to the MCH may already be present and just now showing up.

 

[MrNova]

In that case, would I be better suited scrapping/giving away the RAM i have now and pick up a pair of 2gb sticks (~$50 now) and hope that the motherboard isn't excessively damaged already? Or would I be better paying ~100-150 for a new motherboard and hope that running four sticks doesn't junk it as well?

 

[Blazer]

either way you want to slice it, personally it would be 2X2gb Matched pair of the lower voltage variety and not low latency.

 

[Tarrant64]

You mentioned lowering the timings. Have you tried underclocking the memory? ex: 400mhz -> 333mhz or something like that. (PC3200 down to PC2700 clock speeds)

 

[MrNova]

Yes, I have slowed the clock speed down to 667mhz from 800mhz both with normal timing/voltage, as well as modified timing/voltage.