450nm Creality Laser won't engrave correctly

Hi folks,

I’m really new to all that laser stuff and I have the most hobby setup you can imagine:
Ender 3 Pro + Creality 0.5w Laser engraver.

So I tried many different software and Lightburn is imho most comfortable one! So I decided to post my issue here.
I try to engrave an image of my son. But all outcome till now is following:

A kind of an noise pattern.

In lightburn under preview I can see a fairly nice picture.

Do have someone any clue what it can be?
Is it just my hardware which is not able keep up?

Thanks a lot in advance!

Hmmm… perhaps it has something to do with the pwm mode. I will change it in the firmware to FAST_PWM_FAN. Let’s see what happen.

It’s getting better!
Propably that’s max I can get out of it.

In Marlin under configuration_adh.h there is a option called #define LASER_SYNCHRONOUS_M106_M107.
With this I achieved above result.