Orange flashing light won't stop. i just brought it home from the repair shop where they replaced a hard drive...but I use my laptop on AC power, never on battery alone. The repair guys used the battery during the repair period(2 days)...now the light keeps flashing...is this a trouble warning or will the flashing stop when my battery recharges?

If you are computer savvy, remove the memory sticks and hard drive, fit a new backup cell and power it on empty.
If it loads to no OS on screen, add memory and check again.
If it now fails, replace the memory otherwise fit the hard drive and repeat the test.
That will let you know which way to go about repairing.

You "killed" it -- either the USB-to-disk-drive adapter inside the case, or the disk-drive inside the case.
Remove the disk-drive from the case, and install it in a replacement case (with replacement power-supply).

Try reseating the RAM module/s. If it still does not boot up then then RAM could be faulty, remove the RAM module/s and take them to your friendly computer repair shop and get them to test the RAM for you.

Hard drive needs replacing.

The display driver could have crashed, try holding the power button until the lights go off, and the hard drive powers down (you can hear the spinning stop) then try to power it back on. If that doesn't work, do a hard reset, which would be unplugging it from any AC power, and removing the battery and then reconnecting the battery before powering it on. Should this not work, i would say it's safe to assume the backlight is non functioning and a replacement would have to be ordered.

L300 series boot problems

L300 series laptops are very good normally but don't boot up if there is a device in the USB slot or a CD/DVD in the drive.
If it still refuses to POST, remove the AC Adapter, remove the battery and remove the hard drive.
Power the unit up without the hard drive and it should complete POST and complain that there is no hard drive. If that doesn't work remove AC adapter, ensure battery is disconnected and remove hard drive and RAM. Try again. If it still doesn't work, you have a mother board fault and it needs a service centre. www.Toshiba.com will help you out.
If it does work at one of the options, when you have closed the laptop down, replace the RAM first and test, then the Hard Drive.
Hope this fixes your problem.

We had the same problem. I figured out it was NOT the main battery, but the auxilary battery. The batter life WITH the auxiliary was 68% total, when I removed the 2nd battery the battery life shot back up to 98% AND the flashing orange / red lights were gone (both on the power source and off). I then replaced the auxiliary battery with a spar back up to make SURE that it was not a fluke and with the new backup battery firmly in place the lights still did not flash. Problem solved.

I have had three different laptops, last one an XPS from DELL which did the same thing. Replacing the battery solved all three laptops. How old is the battery you have in there now?

1. Take the power and battery off
2. Remove the HDD re-sit it properly
3. if probelm persists try putting the old HDD

Most likely your battery is dead.
If you are worried about your HD , the best thing to do would be to power it off.
Remove the battery and see if it will boot on the AC adapter.
If it boots , just get a new battery.
If not you have a motherboard issue and need to call Acer if it is under warranty.