Answer to: iPhone 3GS can't onHi Joel has the 3GS been charged up via the laptop and not a plug socket? Have you tried the 3GS charged directly into a mains socket via the iPhone plug? Are the contacts nice and clean at the bottom and could you elimate the iPhone cable by borrowing or using another iPhone cable?
Answer to: Replaced Digitizer not working wellI have just replace my digitizer on my ipad 2 with no problems. Are the ribbons well seated just under the LCD? I have handled a few faulty digitizers in the past but also incorrect handling during installation can sometimes be at fault. The digitizers have tiny squares the form a grid on the iPad, these can sometimes be unreadable. I would consider removing the Digitizer taking great care not to touch the under side of the digitizer, in fact I would wear gloves if you can, surgical gloves are perfect and I always wear them when handling digitizers,mglass ribbons etc. Check the revers side for any marks fingerprints etc. If this fails the digitizer may be at fault Hope that helps
Answer to: glass replacement front screen, screw problems.You need the correct tools, it it worth purchasing the set the site offers or something similar, once you fix this phone you will want to carry out more procedures. Applying a little pressure and a slow anticlockwise turning motion to get the screws moving,as brad said don't end up rousing the screws. Get kitted out and your repairs will be clean and the risk will be far less.