Repair Trimble AG-372 / No response from MPU

[Gabrowsk]

Hello guys, First time posting here and english is not my first language sorry for the typos.

I’m working on a GNSS receiver repair that’s completely frozen and unresponsive. I’ve conducted some tests on the board and have the following observations:

    All power supplies are delivering the correct voltage.
    All crystal oscillators are functioning correctly.
    I didn’t find any short circuits on the board.

I suspect the issue might be with the MPU on the board, an MPC5121YVY400B from NXP. When I try to flash a new firmware version, the board doesn’t respond. I’ve tested both RS232 ports and both CAN ports on the device, but there’s no response. I’ve also checked both the RS232 and CAN communication circuits by injecting a logic signal into the port and measuring with an oscilloscope. The signals reach the test points beneath the MPU correctly.

Does anyone have any tips on how to confirm if the problem is indeed with the MPU? If that’s the case, I would need to purchase a machine for re-chipping, so I need to be certain.

Another possibility is that the issue could be with the NOR flash memory connected to the MPU, but I also don’t have the equipment to test these components.

Does anyone have any ideas on how to proceed?