I have an Windows MCE machine with the following components: Intel S478 Intel 865GL MATX AVL VALUERAM 2x512MB 184DIMM PC3200 NP CL3 2.0 GHz Pentium 4 About 3 months ago, when I turned the PC on, it would give a blank screen with no BIOS (although I could hear the fans and hard drive power up). It started intermittenly and became more frequent. Recently it has stopped working altogether. I changed the powerpack to no avail. I have now unplugged everything from the motherboard bar the power connectors, power button cable, 1 DIMM of memory and the processor (and fan). I have gone back to using the built in graphics card too. Still, the machine powers up but there is no BIOS screen or error beeps. My instict tells me that either the motherboard or processor is broken (although both look fine on a visual inspection), or both are broken, or perhaps the processor thinks it might overheat and refuses to start. How can I proceed and determine where the problem lies without replaceing the whole lot or purchasing, say a new processor, and finding out that it was the motherboard all the time and have wasted money and effort. I can't understand why there are no beeps to help me out. Should I just take the thing in to a shop and pay for an engineer? Wish I'd bought an AMD now!!!! Thanks in advance.