RAM/BIOS/Mobo failure? MemTest errors on every module

[Menthix]

Hope this is in the right section. I need some help figuring out what's wrong with my new system.

The system is unstable (random BSODs). All drivers and the BIOS are up to date. Memtest86+ v2.01 (latest version) shows errors on all the RAM modules (a few in test 3, a lot in tests 5 and 6).

I don't think the memory sticks are faulty. The same RAM was running fine in my previous machine. I also tried modules from another system and got the same type of errors. I suspect it's something with my BIOS settings or a faulty mobo, but i like to be sure. The parts were bought online, some parts from a different store. Unnecessary RMAs could take a lot of time, so how can i be sure it's not a BIOS setting and isolate the problem to a single hardware part?

System specs:

- Mobo: Asus P5Q Deluxe

- CPU: Intel Core 2 Quad,Q9450

- RAM: 8GB OCZ DDR2 PC2-6400 (4*2GB in dual channel)

- Alternative RAM (also showing errors): Kingston HyperX DDR2 KHX6400D2LLK2/2G (PDF link!) (2*1GB dual channel)

- GPU: Asus EN9600GT SILENT/HTDI/512M

- OS: Windows Vista Ultimate 64-bit

What I've tried so far:

- Ran Memtest in various RAM configurations (each socket and module individually), errors every time.

- Disconnected unneeded parts like networkcard, TV card, soundcard

- Disabled unneeded parts in BIOS, like integrated audio and LAN.

- Tried different RAM (see alternative RAM in system specs). Still a lot of errors.

- Tried setting the RAM timings manually, but this resulted in even more errors. I probably messed that up myself, there are a lot of timing settings in this BIOS and it's confusing me :(. Help from somebody familiar with RAM timings and voltages highly appreciated :).

- Reset all BIOS settings back to default.

Still no fix so far. At this point i think it's unlikely the RAM itself is broken. It seems to be the motherboard, but usually just a single memory socket dies, i haven't heard of all four sockets dying before (but still a possibility). Another reason could be the BIOS settings, but at the moment they are set to default, all my RAM in all my previous systems ran fine under default BIOS settings.

It's around 1am right now and i don't want to wake people up, but will do more tests tomorrow. All help and suggestions are welcome.

I'll see if i can get the old system running tomorrow and see what Memtest says on that machine. If Memtest is fine on the same RAM in another machine i guess it's definitely either the BIOS settings or the mobo is failing.

Some google results suggest setting the timings manually and/or a higher voltage to the memory. I'm not too sure about that, shouldn't the BIOS detect the safe default settings? I never overclocked my RAM or played around with memory BIOS settings.

Any help/suggestions?

[gwai lo]

So you have all four DIMMs filled?

Have you tried bumping the northbridge voltage just a step? I know most northbridges don't play nice with all four slots filled.

As for settings, just set the rated timings and voltage your RAM sticks come as. Those numbers are for 400 MHz, but they should apply anywhere under that.

[Menthix]

So you have all four DIMMs filled?

Normally, yes. But Memtest with just one DIMM filled results in errors too.

[gwai lo]

Well, if you've got RAM that's memtesting fine on other systems and assuming all your settings are correct, I'd contact Asus support. All signs appear to point to the board right now (well PSU could play a role, but it probably minor...however I don't know if PSUs can cause problems in the short run like this).

[Robbie Ride]

If Memtest86+ v2.01 is showing errors on while testing your memory and you are sure that the same memory works fine in your old system, try the ramping ur voltage a little, be careful not to burn out your dimms.

Make sure you have the correct dimms for your motherboard i.e 240 pin, DDR2 / DDR3, Non EEC etc. check the manual.

Try a bios update as there maybe a known bug with the current bios.

Disabling componants such as TV Tuner Cards wont have an effect on the memory as the bios should automaticlly set IRQ's but a componant can steal the IRQ's.

failing these checks, it would seem that your motherboard is faulty and will need replaced.

[Menthix]

Thanks for the suggestions.

To be sure i did a Memtest in my old system with the same RAM. This time all modules passed without a single error, so bad RAM modules is definitely ruled out.

I didn't think about the PSU before. It's a new Zalman ZM600-HP 600 Watt. I guess i could test with a different PSU tomorrow if this could be the cause.

Higher RAM voltages don't seem to help. I tried up to 2.20 volt, not sure how save higher values are.

DIMMs are correct for this motherboard as far as i can tell, the exact same model isn't listed in the QVL document on the Asus site tho.

BIOS is running the latests version.

I contacted Asus with a few specific questions, should get a reply within 48 hours. Depending on their reply i'll probably have the board replaced and hope that fixes everything.

[Menthix]

A little update:

- Sent the motherboard back to the shop for RMA.

- Got the new mobo (same model), but it still had errors on default BIOS settings:

- Went into the BIOS and set some of the RAM settings manually:

• Speed: 800MHz
  
• Timings: 4-4-4-15 (CAS-TRCD-TRP-TRAS)
  
• RAM Voltage: 2.14 Volt
  I set it this high straight away because i saw OCZ's warranty isn't broken when using voltages up to 2.15V on this specific model, and i was frustrated a new mobo didn't seem to help. Don't do this with your own RAM, start increasing voltages by small steps and see if it solves your problems.
  

The last thing seems to have fixed all the errors. As far as i can remember i tried the exact same on the old mobo, so i guess it was really broken somehow.

I still need to upgrade BIOS on the new mobo and install Vista, but it looks like everything is fixed now.