Laptop will not power up

Sounds like you covered most of the bases already. The Acer Aspire 4520 may be one of those notebooks that do not run without a battery in place to complete the circuit. Not sure about your model, but I have had a few that need a good functioning battery installed even if running on A/C. Any chance you know someone with the same notebook so that you could try their battery. A long shot I know. Also, if you have more than one RAM module installed, you could try with one at a time to see what happens.

After, your comprehensive testing though, it is seeming to suggest the bad battery or bad motherboard. If you really want to troubleshooting deeper, you can disassemble to the point of removing the CPU and then reseating the CPU tobe sure there is not a bad connection there, since it is the first device to be intialized when you power on. If it doesn't send a power good signal back, the laptop will shutdown to protect itself.

Cheers!

One other thing maybe worth mentioning. With the AC adapter plugged in, the charging light stays on until I attempt to start the computer.

That would suggest that the AC adapter is shutting itself off to protect itself. At this point in your troubleshooting, there is not much else you can do without disassembling the notebook completely and lookin for burnt traces etc and reseating the CPU. You have already completed the most common checks on your own, including booting without the hard disk installed. Perhaps check ebay for your notebook model. Maybe you can luck on to one with a broken screen for cheap and use the parts to troubleshoot further.

I took the motherboard out. The fan spins for about a second when I push the power button and then stops. The power jack board has a black spot on it. Could it be from a power surge?

It could. Sounds like a burnt spot from your description. I think you now need to source replacement parts.

Well I have it up and running. I took the motherboard out and re-seated the CPU but it was to no avail. When I pressed the power button, the LED's flashed briefly then there was nothing(again). Again I took out the CPU and then pressed the power button with the CPU out. All of the LED's remained on until I removed the power. Once again I reinstalled the CPU and all the lights remained on when I gave it power. I reinstalled the RAM, HDD, and the screen. I turned it on and it booted.

Excellent. Reseating the CPU has worked for me in the past as well. Some model Compaq notebooks were bad for thermal cycling, causing the CPU to lose good contact. Feels good to pull something back from almost going to the junk heap doesn't it!

Cheers.

Hi gman0417
I too have the same problem with my laptop. Earlier only the LEDs flashed briefly upon pressing the power button with no activity from any other component like fan, screen, bios etc. Today I dismantled my laptop and reseated the CPU properly. After connecting all other components as well, when I provided power the LEDs flashed continuously until the power was interrupted. I connected an external monitor and found that screen wasn't the problem. What should I do now? You have successfully repaired your laptop, so I am seeking your help.

Regards

Well, after I got mine up and running, it died out on me after a week. I did replace the motherboard and it's been working fine since. One thing though, Windows kept blue screening(even though the motherboard part number was an exact match). I had to reformat the hard drive and reinstall Windows. Then restored from a backup. I thought it was strange.