Jetway 830-CH boot problem

[Sickboy]

AMD Athlon XP1800
Jetway 830-CH mobo (just bought)
256Mb PC133 RAM

Just built this unit and am already pulling out my remaining hair. First boot - got repeated rapid beeps and a screen message saying "CPUFAN does not function properly" the fan is fine, but I replaced it anyway - same result. I cleared the CMOS with the jumper and booted again - it booted to "Checksum error - defaults loaded" ok but when I entered the BIOS to change some settings and rebooted, I got the beeping and the error message again. Seems that if I clear the CMOS it will boot but if I change anything (or even enter the BIOS and don't change anything) it fails on reboot. I tried pressing F1 to continue after getting the Checksum error message and tried installing Windows XP but it locked up while copying files.
I've tried running at 100MHz and 133MHz, no difference.
Any thoughts anyone?

[Rocketmech]

Is the fan connected to the mobo ? make sure the pinout is correct.
After you Clear CMOS , you'll get the check sum error. Just load bios defualts, save , restart. Then configure the bios .
You need to resolve the fan issue before anything .

[Sickboy]

The fan issue is resolved; I disabled the shutdown feature. The PC boots fine now, but will only run properly at 100MHz - if a set the clock speed to 133MHz as it should be, it locks up after a while. I've swapped RAM modules a couple of times and am currently running Memtest86 on the latest module to see if it's just a batch of dodgy RAM. I suspect it's not so any other ideas would be appreciated.

[Rocketmech]

You turned it off ? The temp shutdown or the detection shutdown feature? Just so you know , it takes about 10 sec.'s for the cpu to fry after the fan stops. If its the temp then you might not have the hsf attached properly.

There's a jumper to set the cpu fsb frequency , jumper it to 133/266 . Next, load optimized defaults , then set the bios to detect the cpu clock by hardware. It should auto detect the cpu and set the host/dram clock to 133 /133 next restart . Save and exit. Open the bios to the hardware monitor and check your voltages and temps are good. If you get the 133/133 and temps/volts are good. Run memtest86 again for an hr. and see if it passes. After that your ready to set the boot sequence and load your O/S.

[Sickboy]

I turned off the fan speed shutdown feature - for some reason it is detecting the fan speed as arouns 2200rpm (this is clearly not the case - the fan is running normally and the CPU temp is around 40 deg C at 133/133). I have tried running with optimised defaults - it locks up. I tested the RAM with Memtes86 for around 40mins (3 passes) and no errors. This is a mobo problem - I have swapped out the board for a Gigabyte GA-7VKMLS and everything is fine now with exactly the same components.