My 5100 aspire laptop will not power up

Do you have a voltmeter? The first thing I would check is to see if you are getting 19VDC coming out of the charger. The on then off when you have the battery in sounds like your battery is almost out of juice and the fact that nothing happens when you plug it in without the battery indicates to me that your power adapter is not working.

This is not the motherboard. The batteries in laptops have electronic sensors in them. When they reach the end of life, they stop the computer from turning on. Once that happens it wont power on with the battery in or out. Batteries are not that expensive. Only about 25 dollars.

Try starting it up in "Safe Mode" as it is starting up Keep pressing F12 key, I believe it is. Start up in safe mode, if it starts and runs you probably have a virus.

Sounds like the power jack is loose if you have to hold it in a certain position. As for the screen your inverter might be shot. Try connecting an external monitor to your laptop and see if you get a display.

it is a cooling problem mate!clear your fans and asure that air flow is correct and maybe you left to much computer running and it's over heated

i think the computer gone to power save or hibernation mode. get the battery off from laptop then put it back, turn the computer on. it works, if not consult some hardware technician i think it is not a major problem it can be fixed easily. if warrenty is valid, avail it...

might be a bad hard drive.

try this with only the power and not the battery just to check something out

Check if you have anything loosed in the laptop. Do you think anything was left in the computer loose or was not put together right. Try reseat the memory and maybe the hard druve, dvd rom and see that will change anything.

Hope that can help you. It can be a motherboard issue but I think checking these other things first wont hurt you. You go from the easy to the hardest.

make sure the power adaptor is connected, powered on and your computer has lights confirming that you are getting external power. Make sure your battery is plugged in. Try powering the computer on. Look for any signs/noises from the computer. Try holding the power button down for about 10-20 seconds. Often this can reset the computer. Sometimes you may need to let the laptop charge its battery for a while before it will turn on, Good luck - if this doesn't work, report back with more information - ie any noises, fans, beeps, flashing of the screen that occurs.