Jeep Sentinel controller issue

[milettic]

I have a strange problem with the controller for a "Jeep Sentinel" scooter which shows no signs of life on the display. Specifically, all the mosfet transistors are fine and there is no short circuit anywhere. When I connect controller to the battery, the red phase wire from the display is not powered, which it should be. Also, all the 5 V pins are 0 V.

I tested the display with another controller and it works.

Has anyone had a similar problem or knows what the issue could be?

Thx

 

[neptronix]

We're DIY builders so we don't have a lot of experience with prebuilts.
I'd consider replacing that controller with a VESC if you can't get a replacement display.

 

[milettic]

It seems that there is no low 5 V voltage on the board. There is one lone TO-92 transistor as78l05. Maybe this can be the problem, but I can't inspect before soldering out. For which purpose usual this transistor on the board?

Something like this
Thx