So my Acer laptop screen has been broken for a while. so I just use a HDMI cord but recently it just shows a black screen and I can't see anything. no matter what I do now can I go this?
If your laptop isn't booting and is stuck at the BIOS screen then you won't get a display on the HDMI. You should also double check that your didn't accidentally change the video output by one of the function keys on the laptop.