It sarted when my pc suddenly turned off for some reason then i left it untouched for almost 3 years and last 3 months i invited a repair man and he checked the pc after hes done checking he said that the psu and the fan is broken,then last week i started to buy the parts then i connected it to the pc i turned it on and in the monitor it says vga no signal then proceeds with monitor going to sleep my keyboard and mouse didnt turn on cause theres no light. What is the problem?? Someone please help me and my pc doesn't have a cmos battery