If you are dispatching an aircraft in accordance with the MEL, you are not carrying out any troubleshooting.
I'm fine with that.
My point is that when maintenance is called for any reason, cannot simply act robotically for the purpose on complying with a MEL, as the human brain is supposed to be engaged all the time - except perhaps when tragic errors are made like in this case.
Any engineer or technician knows that when a device supposed to be OFF automatically, remains ON instead , the problem CANNOT be in the device itself, instead SURELY is in the switch or logic powering such device.
If you think anyway that maintenance actions have been 100% correct (no case to respond), then consequenly these cannot even be a concurrent cause.
I just happen to think otherwise.