Will not power on at all

The no#1 killer of laptops is overheating due to clogged heat sinks. Sometime you have to take them apart and clean out the cooling system and replace the thermal paste. Its a repetitive process unless you just blow out the fans every once in a while with compressed air. This answer is directed to some of the comments made. However I believe your issue is a bad power jack.

it can be two things,

the motherboard can be fried or the power supply can be damage. what I would do is troubleshoot both devices with a known good device, the question you have to ask yourself first is: is my laptop still covered under warranty if it is let the manufacturer fix it because this void your warranty. If your not covered and you feel comfortable with doing the repair by yourself DO NOT ORDER PARTS FROM EBAY. I would go to Best Buy or whatever computer store that is close to you for parts.

I have a A505. Power Adapter works fine. When battery is charged it works fine. But eventually the laptop would loose power.

I opened the laptop. Found a glue spot on the internal power connector. Apparently dusts get attracted to it and causes a short. Removed the glue between the positive and negative connections. Problem solved.

I have a toshiba 505 laptop... I gets hot and shuts down... what is the problem?? The fan maybe?... how much are the parts to fix this problem?

I have the same problem. The difficulty is there is no generally available documentation to use to troubleshoot the problem. I have tried a few things but I don't have "THE" answer. I will share what I do know.

The computer was plugged to the charger and used only occasionally for about 12 months. After that, when I turned it on, it would not power up. It was in a stable place and was not moved for a couple of months before I attempted to turn it on. I tried the usual stuff when it would not turn on but it didn't respond.

Because I really like this computer and I cannot afford a new one, I need to "repair" it if possible. I found a motherboard which I bought for only a few dollars, but it was also dead! Caveat emptor! (Sp?)

I examined the board and found several surface-mount fuses. They all checked good. I carefully examined the wires, board traces, etc., but did not see any obvious problem. I plugged in the ac adapter and traced the voltage with a voltmeter, as far as I could, without knowing where it went, or which parts were power supply parts. I was not able to find any lower voltages, so I concluded that the power supply was not operating. That doesn't prove the power supply is the problem-if the problem is in the "on/off" switching for example that will prevent supply from turning on.

Without documentation to further troubleshoot with, I am stuck with just "guessing" and checking to see if I guessed right! I will continue to try. I am an electrical engineer, and prior to that I repaired consumer electronics for several years, so I can guess with a little bit of skill, but it is still guessing. If I find anything, I will make and post a guide here, but I will put the answer here first, as it will take me a while to do the guide. I have been ill for several years so I am pretty slow! But I'll certainly share what I discover (if anything).