IBM ThinkPad Laptop failing to boot

My friend Visopo Harawa brought me his IBM ThinkPad Laptop which was failing to boot. The power LED was indicating that power was coming to the system.

After trying this and that, I realised that the battery completely packed and it was breaking the circuit to power the system. I jumped with joy after the machine rebooted smoothly after removing the battery and retightened some screws on the motherboard. A laptop running without a backup battery?? Yes!! Half a loaf is better than none.