Supplier for smartphone parts

Hey :)

Does anybody know any suppliers from china which is good? I have tried 5, maybe 10 different suppliers from china now and every seupplier have different problems with their iphone screens!

Some of the problems:

The screen doesnt fit well

Bad screen quality

The screen is yellow or blue

The screen does not light up like original

And an another problem which is a problem in all of them:

There are lights from the top, corner or the sides. Even if a use different back housing, the problem is the same. If I put on a screen and open a video where the bottom and top is black, you can see light coming from the top and corner..

So my question is, what to do?? I want to open a repair shop and need a supplier. I have repaired several iphones, ipads, samsung, huawei, sony and nokia for now. Im good at this but cant find a supplier..

I have looked for some sites in England, Germany and Netherland where they sell parts, but its too expensive, like 100 Dollar for 1 Huawei screen? I cant run a shop for this price.. If any of you have a repair shop, please let me know.. I live in Europe :)

Thanks..