Flashing red light / not turning on

Hi,

I have bought a Huawei Mate 20 Pro, Don’t know any previous history of the device. When i put it on charge the small red led starts flashing at the top of the screen and i leave it for an hr/2 still is flashing and doesn’t turn on.

I’ve put a new battery in it but that hasn’t made any difference what could this be? tried putting in in safe mode/recovery mode but screen stays blank. It did show huawei logo once when i put it on charge held power /volume button and quickly disconnected battery but turned off aster 5 seconds.

Also phone vibrated when i plug the charger in and hold power and volume up but nothing shows on display.