Thank you so much for your time and effort! I just ordered a desoldering station which will be delivered in three weeks. (I ordered a JBC one and JBC stuff takes forever to ship to me) As soon as I get it I will be posting my progress here. I will in addition to your suggestions add leaded solder in...

Today I bought myself a scope and I can conform that the MOSFET is not chopping at all. Everything around IC318 looks fine to me and all components on the bottom side are covered by the plate. Even if I could reach them for probing I would not be able to replace them. So I think I have to desolder t...

The IC317 does only get 0.6 V as input voltage. This results in a 0 V output. I do not think that IC317 has shorted out, but I can easally desolder it to try, if you think that happened. I also noticed that after I connect my supply, the voltage is around 1V and then slowly decreases to 0.6 V

So first of all, thank you for your patience and the great support you are giving me! That helps me a lot. I have two multimeters here and they both measure a frequency of around 130 Hz between Pin 6 and 7 of TR301. But this reading is not stable at all and they both show 0V. I think the MOSFET migh...

OBC fault code 39 is also set and charging fails if the AC input voltage is too high. (voltage "abnormal") I have had this happen to me. Before going too much further I would measure the AC supply voltage at the time the charging failure occurs. Do not believe the AC voltage reported by C...

I just checked this circuit and there is a problem there. There is no voltage across C845 present! The voltage enters with about 12 V the connector and gets to TR310. Between the drain of TR310 and the connector ground are still 12V.

Is it possible, that T302 is the problem?

I soldered three wires to the top board to power it up and compared it to skylogger's measurements. They seem to be close enough. 12V DC with a lab bench power supply: C702: 11.712 V C706: 5.1322 V C707: 16.797 V C704: 16.8 V C737: 5.1285 V C701: 11.722 V After that I noticed something. I only draw ...

I measured out all parts involved in current sensing and they are good.

Should I inject a voltage in order to check the 5V generation and is there any point in removing the waffle plate to look at the components under it?

I just checked all diodes with your great schematic and they seem to be fine. I also checked F701.

What should I consider doing next?

Thank you for your fast answer! You can find all the pictures of the boards here: https://imgur.com/a/zUoyObd I just checked the board again and I can not spot anything burn marks or damaged parts. Then I checked all of the diodes I could reach with the diode setting of my multimeter. Diode D301 has...