i took my fan of the processor to get a new one, but the shop didnt have them so i put it back in. when i turned the pc on, it would only stay on for around 5 seconds then it would turn off, after 2 days of keeping on trying to turn it on it eventually stayed on but the monitor hasnt come on at all. just says no signal on the screen. ive checked all the conections, what eles can it be

its a Windows xp, socket 462.

Welcome to PCHF ras85uk,

its sounds like you have a fan issue on your processor. make sure you fan is connected to the CPU firmly. plus make sure there is enough thermal paste on the CPU. if the machine is shutting off really fast then your processor is over heating.

ok now my pc stays on all the time and the fan is working correctly, but the monitor isnt coming on , it just says no signal, ive tried the monitor on another pc and it works fine

so if i kept on turning on the pc is it possible i may have burnt out something on the motherboard which would stop the monitor working, which means i mights need a new motherboard

ok hold on.

You've tried your PC on another monitor and it works fine?

ive tried the monitor on a working pc and it works fine