I changed the fans setup for electronics cooling yesterday. Now, three 40mm and one 80mm fan push the fresh air into the topFrame where is all the electronics. Two 80mm fans are then pulling air out of there. Before, all 80mm fans were pulling air out.

I did some testing yesterday and it behaved now much better. I heated up the chambers to approx 145°C, stayed on this temp around 2 hours and the electronics is still alive :-)  I measured temps on main components and they were more than OK.

Just hope it keeps cool enough also with halogen heaters on.