Problem with video output

Caracoles

Hi everyone, I have a problem with my Beelink BT4.
Every time  I want to turn on the computer, the first time I get a "no signal" message, then I unplug the computer from the power and turn it on again a it works.
I try 2 differents monitors and 2 differents cables, but it still remains the  "no signal" on the monitor, while the BT4 runs with the led on and the cpu sounds like it is running.
Any help?
Thank you

beelink

Sorry for not replying in time
So every time you first turn on the BT4, it will show "no signal"
and if you unplug it and turn it on again, it will work normally , right?