I upgraded the RAM from 128 to 2048 MB. I now get 511 Cpu not detected 512 Chassia fan not detected when I start up. On pressing F1 the boot continues OK. Have checked the specs and see that the DDR2 ram should have a CLS 2.5 value ehereas the new RAM I installed (kingston) has a CLS value 3. Question 1 - What does CLS stand for? Question 2 - Could this difference cause the above named error messages? Would greatly appreciate enlightenment. Larry

I just checked Crucial & your system does accept up to 2GB RAM, 1GB per slot. But since you have a Celeron, you should be running the RAM at 133MHz (266MHz DDR). CL (aka CAS) is the latency. The lower the number, the faster the RAM. CAS2 is fastest for DDR1 memory, CAS 3 is the slowest. Most people get either CAS 2.5 or CAS 3 because CAS 2 is *usually* much more expensive. Make sure you didn't knock something loose when you were playing around in the case. It sounds like you unplugged a couple of fans or at least knocked the plugs loose & they're not being detected.

Thanks Jam for your quick reply. Have double checked the wiring and nothing is loose so I don't think it's that simple. Regarding the celeron RAM settings- can you suggest some reading for me as I don't understand the importance of the different settings (speeds?) Thanks again Larry

Back again. Humble apologies Jam. Having checked connections again -- you were right!! There was a loose wire. Sorry for wasting your time -- but I'm still interested to know why you recommended 266 Mhz for DDR ram. I haven't changed any values in the bios. Thanks again Larry