I use 80 degrees face down and it has warped 2 LCD's. I think I will lower my heat now, leave it longer and only place it back down. Placing the iPad face down means the lcd will be hanging down towards the digitiser, where as placing it back down, the LCD has the support of the battery below it

Pressing on the screen causes a reduction of space in side the phone and would cause the components to press against each other. If you have an IC which has been one or several contacts dislodged, pressings the screen could push that broken contact to make contact again. This essentially temporarily solves the problem. This works for the Audio IC, by pressing next to the bottom right of the Apple logo on Boot up and it seems it may work with the Turtle IC on the home button. The solution is to have the phone inspected by a micro soldering specialist

Can be caused by the baseband IC. If the phone is not able to communicate with the apple server, the phone gets stuck trying to authenticate.

If the tape is the right quality you do not need to heat it. Provided the digitiser flex cables have been seated in the frame correctly and not trapped between the digitiser and the frame, this tape should stick. I use Red Tesa Tape as well, but it is the good quality tape, for the price, it is not worth scrimping on what would cost you at least 1-2 hours time wise for a returned repair, plus the unhappy customer. I only use the tape on the straight edges and use E8000 glue on the corners. This glue is brilliant and gives about 15 minutes adjustment time before it is set. I always then use masking tape to hold the screen in place once the screen is fitted and tell the customer to leave it on for 24 hours. Never had a come back yet

When a battery is being replaced, if the adhesive battery tape snaps off whilst it is being pulled out, the iTech may use alcohol to release the tape. If the screen is still connected, the alcohol may seep under the screen connectors. Although most of the alcohol will evaporate, the alcohol under the screen connectors will take longer to disappear. This will cause the screen to flicker and may even damage the circuit board as the alcohol is causing mini shorts. Remove the screen connectors to ensure there is no alcohol underneath them. Additionally when using alcohol to dislodge the battery adhesive tape, dip the card / tool in to the alcohol as apposed to squirting alcohol in to the phone or under the battery. This would explain why switching the phone on and off several times may cause the issue to go away as the alcohol evaporates.

Try check this aswell. If the adhesive battery tape snaps off whilst being pulled out, the iTech may use alcohol to release the tape. If the screen is still connected, the alcohol may seep under the screen connectors. Although most of the alcohol will evaporate, the alcohol under the screen connectors will take longer to disappear. This will cause the screen to flicker and may even damage the circuit board as the alcohol is causing mini shorts. Remove the screen connectors to ensure there is no alcohol underneath them. Additionally when using alcohol to dislodge the battery adhesive tape, dip the card / tool in to the alcohol as apposed to squirting alcohol in to the phone or under the battery. This would explain why switching the phone on and off several times may cause the issue to go away as the alcohol evaporates.

Here is another option to check. When replacing the battery, if the adhesive battery tape snaps off whilst being pulled out, the iTech may use alcohol to release the tape. If the screen is still connected, the alcohol may seep under the screen connectors. Although most of the alcohol will evaporate, the alcohol under the screen connectors will take longer to disappear. This will cause the screen to flicker and may even damage the circuit board as the alcohol is causing mini shorts. Remove the screen connectors to ensure there is no alcohol underneath them. Additionally when using alcohol to dislodge the battery adhesive tape, dip the card / tool in to the alcohol as apposed to squirting alcohol in to the phone or under the battery. This would explain why switching the phone on and off several times may cause the issue to go away as the alcohol evaporates.

I picked this up from this thread. I believe this can be used as a test to see if it is the Audio Chip IC that is the problem, Turn your phone off. Then turn it on again, put pressure on the screen as shown in the image as the phone starts to boot. This will press the audio chip on to the circuit board. If the phone boots normally, it is the the Audio Chip IC. Here is the link to the article as posted earlier. http://www.fixstop.com/blog/iphone-7-stuck-at-apple-logo-reasons-and-how-to-fix/ More Tests : (1) Open FaceTime (2) Start dialling someone. When the phone starts to dial, press in the same place. If FaceTime works, then once again, it is the Audio Chip IC. (3) Try a normal phone call, as soon as the phone starts to dial, press in the same place and see if it works, if it does, it is the Audio Chip IC (4) Other tests you can perform, Record a video front & back & press the screen, Record a Voice Memo & press the screen Hope this helps.

I had this boot loop issue, it turned out to be the battery connector not properly seated.

I had the similar issue with GPS not being accurate on an iPhone 6. Replaced wifi antenna and hey presto fixed. This is cheap enough option to try. On a side note, there are some techs on here that are just down right rude. Get a grip please, not everyone is a pcb genius like you.