yes thank you zax, for everybody with the same problem and I've fixed it and till now it works like a charme:
I've bought a "Tower Pro MG90s Micro Servo" - the one from tower pro seems to be the original (and I think you can also feel it, when you hold it in your hand, it feels like better quality compared all the other mg90s @ amazon) and now it works very nice.
zax also pointed out:
"the servo power (5V) is provided by the host PC USB port, so an MG90S current draw is marginal (700mA at stall). The SG90 is lower, around 200mA. Most USB ports are limited to 500mA although USB3.0 is typically 1500mA. Remember this also powers the Nano clone." so I've also bought an sg90, but tried the mg90s first -> i can not tell, if the sg90 with lower consumption would also have solved the problem
@Zax how do I know what a genuine laser is?? I bought this 2 years ago so past any warranty was purchased off amazon via banggood so nothing hi can do now as I had problems at the start and stored it and only got it working recently. I'm gutted I can't understand what changed as it was all running fine one day and come the next the laser wouldnt work. I've ordered a new nano do you not think there's a way to solve this? Could you give me a link to a laser if you think that's all I can do?
@Valley-Creations It sounds like you want vector (where the laser follows a path) instead of raster (where the laser scans back and forth). If so, you can either use a vector format (DXF, Sketch, PLT) or you can trace a raster to generate a vector, the easiest option is auto-trace, one click and it's ready to go.
@parveen-arora It is just a straight connection for X and Y1, then to get Y2 to be reversed the coils are swapped.
It is really simple and impossible to cause damage unless you short the wires. If the motor doesn't work that means the coils aren't in a pair, so swap any 2 wires and it will work. If the motor is backwards just swap the pairs.
@bbqqtryjo6 CoreXY has potential 40% increase but in practice it may not be that significant. The standard system is more robust and flexible so you could use a laser or even lightweight spindle later. I would go with the A3Pro.