I have just replace a power supply on desktop pc and all went well. A couple of days later it wouldn't start. Green light on MB working. Removed psu and put back in. All worked. Couple of days later wont start. Replaced psu starts. Then wont start again. Have put first psu back in and it starts. Now wont start again. When i say wont start no fans come on, only sign of power is MB green light.
Any ideas as to what this could be?