My toshiba satellite c855d-s5105 will not turn on. I tried taking the battery out and pressing down on the power button etc but it did not work. I got a new power adapter to see if the chord was the issue because the computer was working fine ran out of battery turned off and would not charge once I put the chord in. Could it be the actual battery that is dead?
Did you try running it plugged in without the battery? At the very least, you can confirm the worst case (if it doesn't run on AC power without the battery, you're likely looking at a far more serious motherboard issue).
I know you tried it with the battery in - did you try running it without the battery and plugged in? If it runs on AC power without the battery in the mix, then it's either a battery problem (good) or a problem with the laptop itself being unable to charge a battery. In the latter case, given that replacing a motherboard on a laptop on the lower end is a horribly inefficient idea financially, you likely have a desktop PC now.
Now, if the laptop isn't running at all with the battery out and AC power, your options are considerably bleaker.