Missing Order...

[if42]

It could be as simple as a voltage or timing problem

I used to work in the systems business - selling tens of thousands of units a year - and sometimes you are just plain unlucky with a product

Already tried absolutely everything. Every component has been swapped bar the CPU....


This is what the problem is:


History (for background) and to help with understanding the actions tried:

Original system built in Jan 2005:

Motherboard: Asus A8n-SLI deluxe, Nforce4 chipset.
- Athlon 64 3500+ (90nm, socket 939).
- 1 Gb RAM, matched pair of Corsair XMS 512Mb DDR 400Mhz sticks.
- Antec 380w PSU.
- WD Raptor 80Gb hard drive.
- Second larger WD drive.
- Asus GeForce 256Mb 6800 PCIE (no extra anything just the rare standard one).

The system was upgraded during summer 2006 to:

- Athlon X2 4600+ (and I updated the BIOS so it supported the new CPU).
- Seasonic 500W PSU.
- Additional 1Gb RAM, matched pair, Corsair XMS.
- GeForce 7900GT 256Mb PCIE.


Symptoms:

- Windows increasingly unstable.
- I spotted the original RAM was being reported as single channel, so took it out.
- Still problems so I ran memtest+ and disovered that the other newer RAM had errors (tests 5 or 6).
- I tested each Ram stick individually, all had (different) problems in memtest+.
- Additionally, the newer RAM sticks, if put in together, report just overt 586Mb ish of RAM in BIOS, rather than 1Gb.

Note - the reason this was not spotted faster is this PC only gets used for games and video/audio editing... and I don't have time to use it more than once every couple of weeks, when I use it pretty intensively.


Actions tried so far:

0. Re-seated RAM, tried RAM in different slot combinations -> no effect.
1. RMA'ed two sticks of RAM to Scan -> Scan reported it was fine (email forwarded separately).
2. Gave the two older sticks to a friend -> tested fine in Memtest+.
3. Bought replacement motherboard, an Asus A8N32-SLI deluxe -> still problems.
4. Put the older, known to work, PSU back in -> still problems.
5. Put the older, known to work, fine GFX card in -> still problems.
6. Unplugged everything bar one stick of Ram, 4600+ CPU, original PSU, original 6800 GFX card -> still problems.
7. RMA'ed CPU - yoyotech reported it fine.
8. Underclocked CPU to half rated clock -> still problems.
9. Manually set timings for RAM (2nd pair that Scan said was fine) to both correct settings, and *slower* settings -> still problems.
10. Took system in to Yoyotech -> tried brand new RAM, passed memtest+ test 5 and 6, with the older PSU and original GFX card once in the shop. I believe it rebooted spontaneously before completing a memtest+ cycle, but the technician may have manually rebooted the PC
11. I bought the new RAM, took it home, ran memtest+ again, it failed twice in a row with multiple errors on memtest+ test 6, I interrupted it each time.
12. Re-ran memtest+ without interruption. It reported multiple errors on test 6, and re-booted on its own during either test 7 or 8 (memtest+ should not reboot on its own), I have photos of all three of these tests if you need them.

So, already tried manually setting timings etc.

Replaced every PC component bar the CPU. The Athlon64 includes an onboard memory controller.

By a process of elimination, the CPU is at fault.

[if42]

Mate u must have a personal grudge with these guys

No personal grudge, at least nothing until I tried to RMA something! Might be one going forward it they don't get their act together though!!!

I have spent thousands with yoyotech and up to Feb was still recommending them to people.

The laptop I am typing this on was bought from them in summer 2004.