[Android Head-Units] kaween:
Hi there, or better said, welcome back. As we're well over the 600-pages mark and I don't know how close you followed the thread, here's a rundown :

1) the "screen goes white" indeed indicates a crashed cpu most of the time. I've suffered a dead board, several other people too. Some got their devices back to work after a reflow (a simple reheat will not work, a reflow ... might). I've done some measurements on the ARM chip back in the days, and the CPU does tend to get hot very fast even under light stress -65° Centigrade under no-load, ambient temp 21°C, open case. Imagine what that results to in a hot car in the summer inside a car that may reach 40°C and up-. Early units had no heatsink what so ever on the cpu's. Later ones do. However, as the airflow in the AN21's is pretty bad (the cpu sits underneath the mcu board, basically making a efficient airflow over the cpu impossible) I have modded my device in such manner that the metal body of the unit is used as heatsink for the cpu.

I would bring the board to a company that does Xbox/PS3 reflow repairs if you lack the gear to do a controlled reflow : they'll give you the most chance of granting the board a new life. If not, the boards themselves are available if you really want to repair it.

2) As said, the newer versions are indeed better equipped to deal with heat, but the heavier rearside is only efficient in keeping the AMP chip at a lower temp. It does nothing for the cpu. Might still consider adding additional cooling procautions.

3) I do not like the sound of the GPS behavior. If you have another GPS antenna (I suspect you'll have 2 now) test with the second antenna. I've written a "how to open the AN without damaging the waranty sticker" guide, so you could inspect the gps-antenna cable that runs from the golden sma-plug to the gps receiver that resides on the ARM-board itself. If you feel uncomfortable about that, I'd return the unit at the first sign of GPS trouble. I've seen only one AN21-user having this kind of GPS issues, and his were indeed the result of a bad gps chip.

4) To get Tomtom to work, you need update 2.8.6 or higher. Other GPS software (Igo, Sygic, ...) should work without updates. Tomtom will work on previous system versions, but will not be able to "see the gps". For a pretty decent free-of-charge offline GPS solution, take a look at Nokia's "Here". (new maps, free of charge). If you want to run Tomtom, be advised it will only run correctly from the internal memory due to bugs in TT. TT1.3 works (tested it myself, use search for details), 1.4 gives issues. When carried out correctly, there's no reason why a system update would break your device.

5) Be CAREFUL with upgrading mcu's. Better said, if your unit works correctly after updating your system without changing your MCU, do NOT touch it unless you have a technical reason for changing it, and only do so if you have access to your current MCU as backup. Seriously : don't change it if there's no need, saves you a world of hurt.

6) I don't know Dash. Can you provide a link ? Or do you mean "DashCommand" ? When I have my workbench back in order and I can use my spare AN21 for experimenting, I'll have a look into that matter. BT OBD will work on AN21's that are equipped with BC6 BT boards. If your unit doesn' t have that (and it won't, as your MCU suffix 2101 points to a BC5 BT board) you can choose a USB OBD, a Wifi OBD with AP mode (they do exist and aren't even expensive, but most are ad-hoc versions) or a specific brand-locked solution (Landu). The easiest, and arguably the most efficient solution will be the USB route.