From Epson Stylus Photo 1400 FAQ on Epson.com Q: I replaced an ink cartridge and my printer still shows that ink is expended. What should I do? A: If you have just installed a new cartridge and you still see an ink related error, the cartridge may be incorrectly installed. Follow these steps to make sure the cartridges are correctly installed: Make sure the CD/DVD tray is not inserted in the printer. Make sure the printer is turned on, but the green power light is not flashing. Open the printer cover. Press and release the ink button. The power light begins to flash. Caution: Do not hold down the ink button for more than 3 seconds or the printer will start to clean the print head. To avoid damaging the printer, never move the print head by hand. Open the cartridge cover. Press down all the ink cartridges until they click into place to make sure they are properly seated. Note: If a cartridge is properly seated already, you may not hear a click. Close the cartridge cover. Close the printer cover. Press the...
If you allowed debugging mode at any point, you may be able to use ADB to force boot the device into recovery. I suggest following that to the end to see if its possible to reboot into recovery that way.
Clean all scanner glass with windex or rubbing alchohol. Look for any marks or smudges on the glass. I have seen white out cause all kinds of problems on scanner glass, but it should be easily repairable. You can also check where the paper would feed through if you were feeding from the top tray and look for a piece of paper or something that might be blocking the image from the scanner bed. If the problem shows up when scanning from the feeder tray, try to lay it on the glass, if it happens from the glass, try the tray. It sounds like something is blocking scanner light.
If the LCD appears to be undamaged, you can replace just the digitizer glass. It can be quite a pain to get the old one off without damaging the wifi antenna and the power flex cable. If you follow ifixit's guide here, and take your time around the two aforementioned parts, it's quite repairable. The adhesive on the glass is quite strong and can be difficult to get off without annihilating the glass. Make sure you wear eye protection and lay something down to contain any glass that comes off. As far as how it compares to an iPhone 4, it's apples and oranges. The iPhone is very cramped inside, but you don't have to deal with glass flying all over the place. The iPad has a ton of space inside, and once you get the glass and old adhesive off, it's fairly easy...once you get the glass and adhesive off. I hope this helps!
I would first check the LCD's connection to the logic board, and the cable's connection to the LCD. If the connections are good, then it's likely your LCD is bad. Be VERY careful when removing the digitizer. If it's not damaged, you don't want to break it when removing it to check the connection, or replace the LCD. Good luck!