Had a scatterbrained moment - set my GS3 down on top of the car while I was loading lots of other stuff into the back seat. Got in and drove away with the phone on top. It finally blew off at about 35 mph in heavy traffic. In the 5 minutes it took to pull a U-turn and go back for it, at least 50 cars and some trucks ran over it.

The glass is completely smashed. I'm assuming the LCD is toast as well.
I can put in a replacement battery and turn it on, but due to black screen I don't know if it boots - I get blue LED and the buttons light up, but then they go out. No sounds, but then it was probably in silent mode, and the vibrator may be physically damaged.

Is there any PC software I could use to diagnose how much is busted?
If I get the compatible MHL adapter, would I be able to mirror the display and at least see whether it is booting up? Or would I have needed to set up something on the phone first to make that work?

I could care less about the hardware - I bought a new phone - but there were contacts and things on there that had not synced with the cloud yet. They don't seem to be on the uSD card.
The new one should be here soon...if I swap the SIM cards, will that bring my old contacts and setup to my new phone?

If not, is there any way to rescue the data from internal storage in a case like this?

 

I've seen gadgets that expand the mini USB port to multiple ports, e.g. USB, and I'm wondering if I would then be able to plug in BOTH the MHL-HDMI and also a USB keyboard/mouse to get around the broken digitizer.

But it's all moot if it won't boot.