Post By demonflesh
Post By noidle22
Repairing EM6910 that pump runs when plugged in
If you plug your EM6910 into the wall and it starts running the main water pump straight away its because the triac (AC switch) has failed.
The triac is used for the coffee pump, steam pump, and for the pressure relief solenoid so all could fail in the same fashion but the main pump draws the most current so is most likely to fail.
It is the component labeled Q1, Q2 and Q3 on the circuit board
I think they cost about $1.60 from RS components.
Make sure to have machine unplugged from all before removing circuit board and label each wire before removing it.
part no: 2N6075AG
Picture links aren't working.
If you don't resolve the issue that caused the triac to fail it will most likely happen again. They'll rarely fail without an external factor.
Uusually a water leak from a split solenoid will drip down onto the board and short the steam pump triac. It's only ever the steam pump triac that fails in this case.
If either of the others fail, I'd be checking to see if there are any water leaks from the o-rings on the pump priming valve or brass fitting on top of the priming valve.
The cause of failure in this case was overfilling the water reservoir which splashed over the circuit board.
Are pictures working now?
Image of triac on circuit board, its the black chip in between two resistors and the green capacitor.
I moved a 6910 on to a work friend. It was ok but is now running continuously on the main pump. I have offered to sort it out for him, and should see it next week.
Will be looking at these triacs closely.
Cheers for the shortcut!