9 years ago, me and my mother went shopping and found a HP Pavilion DV7 1135NR. 3 years after, the hard drive failed on us so just a couple of minutes ago, we replaced it with a working hard drive from my other old laptop. I plug it up with a DELL charger, not a HP, because I cannot find the charger for it. The laptop will turn on for at most 1 and a half seconds when you turn it on. The charger is rated at 1.5 amps when the HP charger is rated at 3.0 or 3.5 amps or something. I assumed that if I let it charge for like 2 hours, it would get enough charge in the battery to turn on but it keeps flashing the charging light. Or perhaps the it's not the charger and it has to do with the battery itself. Having not being charged in 6 years, I would assume that it's dead and needs to be replaced. There are so many possible problems so I think that the charger is not giving out enough power to make the laptop useable.
If it is still plugged in, unplug it right now. Don't finish reading this until you have. Sounds like you have killed it. Putting the wrong voltage through it will kill it, and that's probably what you did. In addition, you could start a fire with it plugged in like that.
Its the right voltage and not enough amperage. I never killed it, just turns on for half a second and turns right off. fans and lights come on and go off.
But how do I know if it's something else besides that? Wouldn't it still charge but take a long time? It's been sitting here charging for 5 hours and still does the same thing as it was 5 hours ago plugged in.
Maybe one of your friends shoved one of these into it? It's a USB that charges with 200 volts from your computer, then rams it back in, killing your computer
if it is old then there is a high chance that the battery is dead, so it wont take a charge, so letting it charge will make no difference, you will need to find a decent power adaptor capable of 3/4 amps (higher the better), since right when you press the power button there is a huge power draw, all the fans are spinning up, so is the hard drive, power is surged through the motherboard. Just get an appropriately sized power adaptor, 19 volts and 3.5 amps.