I have a Lenovo M58 which i opened up the other day to format a new HDD to use externally (its no longer in the machine) But after closing the machine back up it wont power on at all not even for a split second. I was careful about static when the machine was open so I think it could be the power buttons not working? what's the best way to find out if it is this? if it is what's the best way to get round this problem?
First check out the simple things. Does this computer have a reset switch that must be reset after opening the case? The User's Manual will explain this feature.
The motherboard has pins for plugging in the "Power" and "Reset" connectors. Unplug the Power connector are carefully short out the pins on the motherboard using a flat blade screwdriver. This will tell you whether it is a switch problem. Do this at your own risk, and only if you feel comfortable doing such things.