I have a chip on a DJI Phantom 3 Advanced controller/remote. It is the RF communications chip, which I believe to be some sort of Analog Devices wireless networking chip, but I'm not sure exactly which one.
My goal is to identify it in order to interoperate with it from novel hardware. DJI however has obscured the chip (all major chips, actually) on this board with an epoxy goo covering on each.
I practiced on a couple other chips on the board with limited success. The main CPU (an Altera ARM core) epoxy came off ok with careful in-plane scraping with an xacto knife, but the RF chip is surrounded by a the sides of the RF isolation cage and it isn't easy to scrape that way.
Per some other recommendations, I tried grinding with a wooden toothpick in a Dremel tool on another chip, but so far that hasn't been effective in revealing the chip ID there, and I don't want to try it on the important chip yet in case I make it illegible.
What techniques are good for removing an unknown epoxy from an obscured chip?