Note to moderator: I reposted this thread under the same title because probably no one saw my previous thread
as it took a while to be approved by a moderator (probably because I posted it just before the weekend)
so you can delete the previous duplicate thread.

Hi, I have had this problem for years and thought I'd try again.
I plug the charger into the 7551G laptop and it's just a black screen, the laptop fan starts but it doesn't boot.
I believe this may be due to a corrupted BIOS.
I previously solved this problem by doing what this website suggested:
It worked once (don't remember which USB port I used) and it revived the laptop.
But after putting the laptop in sleep mode for a long time, the black screen no boot problem returned.
I tried removing the battery, HDD and RAM, no change.
Next I tried an alternative method, last post on here:
1) Instead of the CRISDISK method, I tried the above method.
So I used the software Rufus (portable) to format a USB flash drive to FAT32,
FreeDOS bootable, as shown in this article:
2) Then I downloaded the 7551g BIOS zip from the Acer website, unzipped it.
I copied the files from the DOS folder into the root directory of the USB.
In the FLASH.bat file, I edited it, removing the line containing the word "pause" and saved the bat file.
3) Next the Acer post above suggested making a duplicate of the FLASH.bat file
and renaming that duplicate to autoexec.bat
4) But there was already a hidden file on the USB called autoexec.bat
so I tried both skipping that step and also tried
renaming the hidden one to allow this step.
Neither worked.
I put the USB into the laptop (left and right USB port).
Held down Fn and Esc while plugging the charger into my laptop,
after 10 seconds, the USB light is not flashing.
So the laptop isn't reading the USB?
What could I be doing wrong?
Any help is appreciated!

Please note: my power button doesn't work (the power button ribbon is damaged, don't know where to buy a replacement ribbon).
I also notice my USB keyboard does not light up when connected to the laptop
but my USB flash drive light does turn on (but does not flash).
Tried
both the USB keyboard and USB flash drive on the same USB ports, and
different ports, same result. Anyone know what this means?