Heater fault, including one unused

[audryhome]

I have a small printer (Fabtotum reengineered) using E3D V6, only one heater, and it stopped working suddenly today at power on. Tried to switch to the free remaining heater port with updated config.g (e1heat instead of e0heat) but no result. Leds don't light up as well.

I think about a hardware failure, so I would like to diagnose the problem, and possibly cure it.

My board is a V1.03 bought in 2018, so out of warranty.
I suppose the lack of fuse for heaters in this board version is also part of the problem, I didn't notice any short on the heater wiring, it shows 20 Ohms. Could an bad contact (this heater is connected through a 2 min Molex) be the culprit because of the wiring inductance?

Never had any heater nor any other fault on this machine, worked like a charm until this morning :(.

Many thanks