Puzzled over BSODs and RAM

[veblen]

Hello all,

Stumbled upon this very useful forum while googling for information on BSODs. I've browsed some of the topics and unfortunately, find that my PC suffers from a multitude of them - the reboot loop, repeated BSODs, etc.

I've done the necessary diagnostics using memtest and orthos and indeed, with my current mobo (ASUS P5VDC-X), pretty much all the RAM modules I have fail the tests with errors writing to ## or inaccurate division (the 0.5/0.4 message that orthos spits out). However, on a different mobo, these very same RAM modules pass an overnight memtest and orthos run. This gets me puzzled - is it a RAM problem or my motherboard?

I am currently using no-brand Nanya PC2-4300 512MB X 2 mem modules running at 310MHz (on a Pentium D-805 at 3.10 GHz.) Despite the errors from memtest, it seems stable for normal tasks until I start a game...then the game will quit abruptly with an error. I reverted back to stock settings and the same things occur. At this point, I can start XP only with these mem modules. (I removed Vista since the boot manager was really getting screwed up and when I boot from DVD, after the loading process, I keep getting error messages.)

When I switched to my newly bought Kingston ValueRAM DDR2-667 1GB X 2 initially, I kept getting random restarts all the time. Now, my machine goes into a repeated reboot loop or if it manages to get past that, says something about corrupted BIOS (even after I cleared the RTC RAM and reflashed it) ) _and_if I manage to get past that, it's BSOD galore. (at stock settings)

I try to boot from CD but once the drivers finish loading, I get a BSOD when the message "Windows is now starting" comes up...I can't even get to press R for repair!

I'd appreciate any insight! I thought DDR2 RAM was backwards compatible and I could possibly achieve higher overclocks but at this point, I may have wasted my money. Also, since the same RAM modules work with no errors in another machine, is it still a RAM problem?

I'm using a 430W PSU with an AGP 7600GT that requires an external power connector, a SATA HDD and an IDE DVD-RW.

Thanks in advance for any suggestions!

 

[Tmagic650]

You have done evertything I can think of as far as troubleshooting. Bios clearing, memory testing, power supply ok... My only other thought besides a bad motherboard, is that the modules you are using, both the generic and the Kingston are incompatible with the Asus motherboard

 

[herr5407]

I thought DDR2 RAM was backwards compatible

Does this mean you plugged in DDR2 into a DDR mobo? or vice versa? I may have misread

 

[Tmagic650]

I thought that myself for a second... The modules (DDR and DDR2) are not interchangeable! The pins/keys are different. DDR is 184 pins. DDR2 is 204 pins if I remember

 

[herr5407]

DDR2 has 240 pins.

If you did plug DDR2 into a DDR slot or vice-versa, I can almost garantee that you've either damaged your motherboard, the RAM itself, or even both.

 

[veblen]

No no, this mobo has both DDR and DDR2 slots (one of those AGP/PCI-E, DDR/DDR2 VIA chipset kinds). The problem started occurring after I installed the Kingston DDR2-667 in the DDR2 slots, despite the max. recommended DDR2 DIMM speed of 533. Shouldn't the DIMM automatically downclock to run at the lower speed? I only bought the 667 coz I wanted to ensure that if I were to upgrade, I could still use my mem modules.

When I try to switch back to my old DDR-333 RAM (just DDR RAM in the DDR slots, nothing in the DDR2 slots), I get error beeps and the machine refuses to POST.

 

[Tmagic650]

Replace the motherboard...