Question Acer Aspire One laptop: black screen and a single beep when plugging the ac charger in ?

[Samd94]

My Acer Aspire One laptop (running Windows 10) has a black screen (back-lit still on screen) and beep once when plugging the charger in. I have tried numerous fixes looking at endless forums.

• Connecting an external monitor but remained black screen
• Changed power option settings
• Tried a different charger with the same volt and amp output
• Opened the laptop and removed battery ensuring the pins are clean and functioning
• Installing all the windows updates
• Disconnected the ac charger and pressing the pin hole underneath the laptop for 5 seconds leaving it for 10 minutes, plugging the laptop in for a further 10 minutes
• Checked drivers and all are up to date
• Intel graphics settings (60 hz refresh rate is my only option)
• Factory reset
• Changing the brightness slider (by clicking the battery symbol at the bottom left)
• Fn+ brightness up and down
• Pressing Fn+ sleep button twice (remains black)

This really has me stumped, it seems as if I've tried 99% of things that should have fixed this issue. What confuses me the most is when I use teamviewer on another working laptop to remotely control the faulty one, the screen remains on upon plugging in the charger and works fine but the moment I disconnect on teamviewer it instantly goes to a black screen.
Any suggestions would be greatly appreciated.