Graphic chip doesn't work
Would it work if I unplug the graphic chip by disconnecting it from the power supply? Would the cpu-integrated graphics - ia intel i3 - work on its own?
You cannot separate them and as the CPU is probably mounted on the systemboard you cannot easily change the CPU either.
What is the problem with your laptop graphics?
If you have no display what have you checked?
Have you tried connecting an external monitor for example to check if there is a display on it when the laptop is turned on?
If there is an image on the external monitor:
Have you checked the laptop's display, using a torch at an angle close to the screen to check if there is an image there or not? It will be very faint but if it is there you should be able to see it. If there is an image detectable, then you may have a backlight problem.
If there is no image on the laptop screen there may be a problem with the video cable, video cable connections at either the systemboard end or the screen end or the screen itself.
If there is no image on the external monitor either then you have a systemboard problem