If it’s really broken and you still have warranty send the result of the touchscreentest to support to get it replaced. Otherwise you’ll need to buy a new display and use the ifixit guide to replace it yourself or take it to a repair shop.
Sorry for the late reply. I just tested (I’ve never been in testing mode myself before.) I don’t have the english translations in brackets besides the mandarin characters, but by pressing the volume buttons and power button exactly as described in the wiki I can navigate to the touchscreen test and back to reboot.
You probably ended up in the wrong menu somehow…
I do have FP1U, but I forgot to mention that I’m running the beta version of the new Android 4.4 update. That’s why I don’t have the english translations, but the menu is otherwise the same as described in the wiki.