Not able to power on PineTab anymore

[zkajdan]

Hi, hoping that maybe someone has advice on this...

After finally getting my pinetab connected to wifi, I ran

Code:

sudo pacman -Syu

for the first time, and suddenly during the update I got a big message

Code:

This screen locker is broken and unlocking it is not possible...

and from there on, the pinetab did not react to anything anymore...
I tried to restart it, but after it had successfully been powered off, I've not been able to power it on anymore... It just stays dark.
I've also tried connecting to the laptop via the UART console, to see if it's just the display - but I don't see anything in a screen terminal either.

I have no idea what to do, since I can't re-install without somehow switching it on...

Would anyone have an idea what to do? Many thanks!!