My Kenwood works again and I want to thank for these great instructions.
One capacitator and the Triac were burnt. I spent quite some time researching the solution and then finding the replacement parts.
Now that everything was ready on my workbench, the repair itself took two hours straight. I replaced the three capaciators and the Triac. I did not replace any resistors, because none appeared to be burnt.
Unsoldering was done with a 100W electric soldering gun. The soldering iron I usually use for electronics, did not heat the solder joints enough.
When unplugging the battery, the femaile plug ripped off the PC board.
The reason was that in my case, the plug of the battery was secured to the PC board with a foamy tape. I should have pried off the tape with tweezers before unplugging the battery.
conclusion: Without precision soldiering this camera is destined to the land fill.