So I dived some tablets including one of these puppies with a busted touchscreen:https://shopnuvision.com/collections/windows-tablet/products/tm101w625l-10-1-2-in-1-tablet-pc-with-windows-1
Researched online to find out you need at least 200F degrees to soften the glue holding the LCD and touchscreen together. 230 degrees will burn the LCD. A hair dryer won't go beyond 150 degrees, so is useless. A heat gun gets plenty hot enough, but there's major risk of burning the LCD and/or nearby plastic parts.
I decided to put the tablet in my gas oven, used this dived digital smokehouse thermometer to make sure things didn't overheat:
I removed the motherboard and battery, put the frame in the oven for 5 minutes between 190 and 200 degrees. Was able to lift up the glass about an eighth of an inch, then slowly worked sideways a couple of inches with a small screwdriver blade. I had cut a plastic gift card into 1/4 inch wide strips, I slid these in between the glass and frame to keep the glass from gluing itself down again. Slow going, I put the frame back in the oven for 5 minutes every time I'd loosened up another couple of inches. It eventually comes apart with no apparent damage to the LCD or other tablet parts. Speakers fell out due to their adhesive softening, but went back in easily.
$23 digitizer on order from China, should be here by the end of next month.
I did put a couple extra cracks in the already broken digitizer, no biggie. A broken digitizer with good LCD is the most likely scenario you'll encounter. The trickiest scenario is if you try to separate a good digitizer from a bad LCD without breaking the former. I would likely have heated up to 220 degrees in this case to get the glue really soft.
Here are some other dived goodies:
A working 8 inch tablet that I'm using as an audio player for my talk radio shows, Zagg keyboard dived last year:
I had to reinstall the drivers for this via USB. I went to use the camera feature. Rear camera worked fine. I switched to the front camera, causing it to bluescreen, reboot and delete all it's drivers again. Guess I won't be using the front camera.
Keyboard for another 10 inch tablet:
Also a no-name 7 inch tablet with both motherboard and screen smashed. Battery pack consisted of 2 2500MAH pouch batteries connected in parallel. I harvested them and put them into a $4 large USB battery bank case that was intended for 6 laptop cells:
Battery chemistry/charging voltage is identical between the pouch batteries and cylindrical laptop cells.