[Solved] Delphi DS150: Multidiag Pro Repair Assistance - Voltage, LEDs, ARM STM32 & Laptop Detection Issues

Hi, I got a tester for repair, as in the subject, i.e. Multidiag pro ds150, unfortunately this task exceeded me and I am looking for help. The tester was already in the repair with some guy, but he returned unrepaired and even more broken. The tester was damaged probably by detaching it from the car during the test (as the customer claims) since then the tester was not recognized by the laptop only red LEDs were lit, then just got to repair for this guy, after trying to repair nothing is shining and through the laptop also not detected. I checked the voltage and it's about 12V to the tester comes later after the LM2575 converter is 5V and after the stabilizer ams1117 is 3.3V. The reset button comes to 3.3 V, hence the processor has power. Where or what else can I check?, How can I judge if the predecessor did not burn the processor (ARM stm32). If one of my colleagues has already repaired such a tester and knows where to look, I will be grateful for any help.

It makes sense to tire and repair the device for such money?

It all depends on what has been damaged if a small element is probably a good thing and if the processor has been damaged, I will definitely not even try to replace it, so I ask you how to tell if one of your colleagues is already privy and knows what could have been damaged. When I took pictures, the adjustable stabilizer lm 317 in the housing SO-8 wonders what voltage should be on its output and what it feeds, tomorrow will measure what voltage is. Or maybe someone has a schematic of this device.

The tester repaired the topic I am closing.

The tester repaired the topic I am closing.

Added after 3 [minutes]:

Corrected February and the path from the USB plug, the tester then became visible and its software was updated. Renault trafic merged without a problem.