A few days ago I decided on a whim to 'attempt' to take apart our very old and only desktop PC, no one uses this PC so I thought what the heck, just wanted to get a feel for how everything works. Now this PC is about 8-10 years old, so I am sure it was already quite close to it's death bed. I removed all the components and motherboard from the case, gave it all a good clean (10 years of dust is not a nice sight.) and put it all back in without a hassle. When I booted the PC, my CRT monitor goes out of standby and says "No signal found !", whereas if I remove the GPU card nothing happens so I assume this means that it is detecting the GPU but something along the way is going wrong, terribly wrong... Another thing is that I am getting zero beeps from the internal buzzer whatsoever, even when I removed both RAM sticks I still get no beeps, and I know it actually has a internal buzzer because I checked myself, it's a KC-1206 (Whether it is alive or not is a different story.) So at that point I could only really assume it was the CMOS battery... I removed everything again, only putting back in the PSU, CPU, GPU, 1 RAM stick and the Heatsink fan/CPU fan and this time it powers off after about 15-20 seconds, with the same display problem to go along with it... Now my beliefs are that the PSU has started to die now, causing the power off problem (Or possibly overheating?) or/and the CMOS battery on the motherboard has gone which would also explain why the internal buzzer on the mobo isn't working... As for the reason I am getting no output display, I am clueless. Yes, the monitor works, I have tried it on multiple other Computers. There is probably more stuff I meant to say but have forgotten but that's all I can remember for now, I don't plan on buying any new parts for this Computer as I will be attempting ( ) to build my own computer within the next few months, so if it is dead, then so be it. Just wondering if anybody has any suggestions/ideas as to what I could do from here to get this system working, albeit highly unlikely. If needed I can provide pictures.