Sevcon GEN 4 motor controller repair

[Drirr]

Hi guys, is there anybody experienced with sevcon GEN 4 motor controllers?
I am trying to fix two of them, both were used in electric scooters. One was fully functional and then died while not used long time, second was not funtional from beggining.
Symptoms - first one, LED blinking 10 times, after diassembly without cables, blinking 6 times.
Second one, trurns on, when I try to run motor it turns a little bit and then switches off and start blinking.
What I checked on first one:
1) voltages are okay, DSP 3,3V, 1,8V, voltages for opamps OK, all three contactor MOSFETs OK, input protection diodes are all open - TVS? All TO220 MOSFETs ok.

Any ideas what to do next?

[Slh]

I've used some Sevcon controllers in the past. First and foremost - do you have the manual for that controller? The 10 blinks is trying to tell you something (that's the most basic way of communicating errors) but I don't know what error it is. There's a good chance that 6 blinks is just "error: no battery or no motor connected".

The second one could be an issue with the position sensor. I assume that it uses hall effect sensors for the position sensing so it might start running as it assumes that both of the hall channels are high. When it hasn't received any updates from position feedback it would stop working. Again, count the blinks and compare with the errors in the manual.

[fzabkar]

Assuming N blinks means that test N failed, I would take the second unit and non-destructively create faults on it. By observing the resulting error code, you may be able to determine what each test is doing.