Possible issue with RAM modules

[enigmaboy]

My current configuration:

 

AMD Athlon XP 3200

2 512mb Corsair DDR400 PC3200 modules

eVGA GeForceFX 5900 Ultra 256

Asus A7N8X-E Deluxe MB

2 SATA seagate 120 7200rpm hds in Raid 0 cfg

Antec truepower 480w psu

The memory timings in the bios are set to auto, as they were in the original cfg on my old motherboard, which ran fine for nearly a year before the problem.

 

My issue is this, without having made any hardware/bios changes, my computer suddenly began booting up and having the screen covered in scrambled garbage, lots of lines and rectangles all over the screen. I thought this could initially be a problem with the MB, which was a A7N8X Deluxe, I replaced the motherboard this week with a slightly upgraded A7N8X-E Deluxe, and I'm getting the exactly same problem.

 

After rebooting several times, I'm finally able to get into the BIOS without the screen scrambling. The only way I'm able to get my computer to boot without any graphics scrambling is to reduce the FSB to 100mhz, which is an effective 200mhz after the multiplyer. And then the computer boots normally, however with the CPU and ram running at half-speed. In order to rule out any problems with the video card, I tried it in another machine, and it booted up without any problems. I ran the MS memory diagnostics test, which took nearly forever to complete, but it didn't find any problems with the RAM, nor did the passmark burn-in, but again this is at half speed FSB. Having replaced the MB and tested the video card in another machine, the only thing I can think of is that the RAM is somehow faulty, or the CPU is at fault. I read through the boards but I can't find anyone with a similar issue. I was wondering if this is a possible occurance due to faulty RAM? I just find it strange that everything will work fine with the FSB set to half speed. I wanted to check with you for any other possibilities before I request an RMA on the modules.

[RAM GUY]

Can you tell me the exact model# of your memory module, and if you bought it as a pair or kit?

[enigmaboy]

The ram modules are CMX512 3200C2. They were installed by ABS PC as a pair. And like I said, everything had been working great for a year, the problem just appeared spontaneously.

[enigmaboy]

any ideas?

[CMC_SAVAGE]

Have you tried a different monitor?

It seems more vide related than anything else, but you said the card worked

fine in another system.

When you swapped MOBO's did you check the jumpers to see if they were set for a 400 MHz FSB?

Normally they are shipped with the jumpers set for the lowest FSB to prevent CPU damage.

[enigmaboy]

I've tried with two monitors, and I'm getting the same problem. The jumper on the mobo is set for 400mhz fsb, but like I said, I can't get it to boot without scrambling unless I set the FSB to 200mhz via the bios. The only thing I can think of is that the other PC I tried the video card in was an older system with a lower FSB, so perhaps it's the video card that has stability issues with the 400mhz FSB. Perhaps the vram has gone bad? Either way, it's frustrating the heck out of me.

[RAM GUY]

The FSB jumper should be set to Pins 2-3 furthest away from the CPU and the modules should be in slots 2-3 and please set the Dim Voltage to 2.7 Volts and then test with http://www.memtest.org.