Troubleshooting and repair for On-board Charger (OBC)

[kiev]

Sounds like you have damage on both the AC input side and the DC output section, that's somewhat of a puzzle as it's usually one side or the other, not so much both.

[Lic]

I don't see 9,6Om resistance between points N00 and waffle board N contact, so one or both 4.7Om resistors are dead.

[kiev]

WOW! Never seen so much smoke damage before, that thing really exploded.

There is discoloration on one of the white ceramic resistors--that one may be cracked.

[coulomb]

WOW! Never seen so much smoke damage before, that thing really exploded.

It looks to me more like an arc flash than a component burning. The fibreglass of the printed circuit board will have been damaged by carbonization, which is bad news as it is conductive. It will be difficult to clean all the blackened material so that it is safe for high voltage DC operation again. Every last spec has to be removed, and a good conformal coating applied. It may not be practical to repair that board, depending on the damage.

[Lic]

I was able to reach resistors contacts, so resistor with discoloration is fine, other one (P10K fuse) is dead. I don't want to remove waffle board (but I can - it just takes time), so I will try to reach resistor contacts by soldering iron or may be I will try to cut bad resistor to reach his legs. Also I checked diode voltage drop and it looks fine.

[kiev]

oh yes i agree arc flash is more accurate description.

You probably should check or replace the AC relay since the ceramic resistor fused. i'm guessing maybe for some reason that relay opened while charging--that might explain the damages.

[Lic]

AC relay is working fine. I checked several times.