It appears to be a hardware problem, most likely a dead motherboard or CPU.
Try this:
Disconnect and emove HDD.
Disconnect and remove all RAM sticks.
Power on the computer.
If it gives you a series of beeps, then the motherboard is OK and it might be the RAM that’s causing the problem.
If you hear no beeps, then the motherboard/CPU is most probably dead.
If you hear beeps, try booting with one stick, then the other (if you have multiple sticks of RAM)
Another thing to try is leave the laptop unplugged for about 30mins without the battery, then connect to power and boot. If no go, then try the same thing with battery unplugged overnight.