Kelly KLS6035s Water/Corrossion damage.

[Amiran]

Hi all,
Anyone know how to trace the issue with failing Kelly KLS6035S after water ingress and corrosive damage?
I know there a 100 ways water could damage the electronics but here it's state now.

All started after leaving the bike in heavy rain for a days and days:
Controller stopped turning the motor and indicating overvoltage error code when voltage was well within settings and below top allowed by manufacturer.
It would work for 2-3 second after reset.
After about an hour from failure it started showing reset error code.
After reset it would show green status led and give big single BANG in the motor without turning it.
Reset Error code after the loud bang in the motor.
About 10 times I have tried - reset -bang - on off reset error.
Extra drag on the wheel when pedalling - With power off state on the controller.
Controller is communicating with PC - displaying all the external sensor information and accepting setting change as normal.

Water leak found after teardown was not massive and there was green stuff under the last Mosfet. The same Fet has smoked the pcb under it's feet. (attached)

I will appreciate and suggestion with troubleshooting. I now run massive 500A KBL and It is lacking variable regen option + scaring crap out of me when accelerating with unnessessary torkue on startup (does not make much sense on 20' wheel just lost of energy)

Thanks

 

[amberwolf]

Water leak found after teardown was not massive and there was green stuff under the last Mosfet. The same Fet has smoked the pcb under it's feet. (attached)

Some pretty serious corrosion started there. THe green stuff is corroded copper. If the heatsink there is not copper, then taht means it's corroded the FETs themselves, and probably shorted them to each other via the heatsink. (at least, any of them that got wet)

When the FETs are shorted like that, it could blow them up (often failing shorted or at least lower resistance than they should be).

When FETs blow, the gate drivers for them on the board can also blow.

Any other parts that got wet, including PCBs, may also have corrosion like that, possibly under the component bodies where you can't easily see it, and the corrosion is probably not bad enough to disconnect things from each other (breaking traces/leads) but it could easily be enough to either directly or capacitively couple signals to places they shouldn't go.