Power not reaching the motherboard

[chenx]

Hello,
I have a PC motherboard is Mercury PVM900M. it is failing to power on. i have checked power suply it is fine , cpu fan also perfect. first day it started I tried to remove switch cables from the panel and put it back agin and tried to push in the cables hard and the fan rotate after removing fingers from the cables it stopped. Later I switched it on without using the on/off button I removed switch cable from the panel
and it worked .I retauned back the switch cable on the panel and tried to switch it on it refuses it is now two week I have been trying.

Please help what could be the cause? and the way forward

 

[o1die]

Maybe it's just a bad case switch. New cases start at $35 shipped at newegg.com. I wouldn't start handling components without an esd strap. some places sell them for $1. It's good insurance if you're not used to working with electronic devices.

 

[chenx]

I tried even to remove the system board from the case and tried to switch on out side the case