I know no one will read this, but better than guessing, better than
imainging what might be right or wrong, you should test and find out
for sure what is going on. You should find out what voltage the
charger should be, and you should read the spec on the hp charger to
see if it is as many volts as is needed, and not tooo much bigger.
You should also verify that the HP charger is working by using a
voltmeter to measure the output voltage. Since you can't easily
measure the voltage when the cord is plugged into the computer, you
have to measure it when it's not connected, and with no load, the
voltage should be hire than what is needed.
On the ACER D250 and many other Acers, the voltage shoudl be about
19V.