The lithium batteries last 3-5 years. A dead battery would not
cause your problem.
Have you tried the steps below
? If the computer is upright and you are looking at the motherboard, try looking in the bottom right corner. The CMOS jumper is usually located near the battery and the "case pin connector strip"; where the case wires attach to the board.
- Unplug the A/C cord again from the tower then press and hold the power button for 15 seconds.
- Locate the three pin CMOS Jumper on the motherboard (consult your computer documentation) usually located near the case pin connection strip and labeled "CMOS." It is usually jumpered 1-2 (default) . Move the jumper to pins 2-3 for 20-30 minutes. This will reset BIOS to factory default. It's helpful to remove the circular lithium CMOS battery at the same time.
- Replace the battery and set the CMOS jumper back to pins 1-2. Test the computer by plugging in and powering on.
- If still unsuccessful and you have access to a known good power supply, try to swap it out and see if it boots.
I had a friend recently who thought that he had a bad power supply so he took the computer to Staples and a tech swapped it out for him while he was there. It turned out to be a motherboard problem. I don't believe he charged him. My friend never did fix the computer. It's worth a try before you buy one and find out that it's not the problem.