You need to determine if it is a power issue or a data issue. A close visual exam is also extremely important. You said it looked like it had been thrown against a wall.
· The .48A is coming from your DCPS and not an amp meter?
· Check all NAND power rails are producing the correct voltage.
· Check all coils around CPU for cracks as this happens on the 7 series.
· Try putting it in DFU mode.
· Put some pressure on the CPU and prompt to boot.
These can turn into time consuming repairs but as I said you first need to determine if it is a data problem or power problem.