Possible problems in the case of DVR non-start
1) if nothing is on, check the power supply.
2) if the blue led is lit - at least started the bootloader and possibly,
system kernel.
3) if the green led is on - the operating system of the DVR
fully or partially running, the Pittasoft applications are not running.
This may be due to problems in the firmware itself, poor quality
firmware updates, and due to damage or errors in NAND Flash
registrar's.
4) if all LEDs are lit, it is a BRICK. That is, even the bootloader does not start.
Procedures for the recovery of the recorders of the situations 2 and 3 are already fulfilled
our team, the procedure for fixing errors on the NAND flash drive Registrar
and system restore-too.
https://car-dvr.info/forum/index.php?topic=212.msg4920#msg4920