Hi REGFly,
The contact between the screen and the PCB is made by a small conductive piece of rubber on the back of the screen, so you can't solder it. Make sure it's clean and in place. You should get a look at the
Troubleshooting page, it explains how to solve screen problems. Sorry for the inconvenience, remember the screens are recycled from old Nokia phones, even though I assemble and test each of them individually before I ship them, some of them might not be super-reliable (yet, most of them works flawlessly). If you really can't get it to work, you can check on eBay, you can get a replacement one for really cheap.