This common problems on Sony Ericsson Xperia X1 like, touchscreen just stops responding once slide out the keyboard, ended up black screen when slide out or open, the phone sometimes has no image at all when the phone opened and can only work in portrait mode.
(If you are a standard user by this product you can check the warranty period of your Xperia X1, if not yet expired you can send it to the SE service centers for repair.)
This all problems exists when the flat flexible cable wire on Xperia X1 is being damaged already.
At first of my encounter with this, I have tried to hard reset the device and tried different ROMs but the problem still persists. So the only solution for this, is to replace the ribbon cable wire to fix the problem.
Mostly most of my repair history on Xperia X1 got this common problem from many standard users. Xperia X1 was released last 2008, October if I'm not mistaken, but almost got over hundreds of it I got repaired with same problem issues.
Here's the disassembly guides for SE Xperia X1 from trusted sites:
Anyway, you can purchased a replacement Flat Flexible cable or ribbon on ebay. Do not even try to buy an imitation one, or you might experience more backjob from your costumers, that outta possibly happen.
"this cell phone repair tutorials post is an answers to all who are asking solution about this problem via my e-mail"