Some more pics from the inside of F107
The xwhatsit is connected directly to the buzzer.
Is that supposed to work? Shouldn't there be a driver board inbetween? Looking at pr0ximity's restoration thread that should work.
There's a schematic in
this post, but I'm not sure which way the cable should be oriented. Looking at pr0ximity's setup
here, it seems that controller 5V was connected to the buzzer GND and vice-versa. Could that have killed the buzzer? I tried twisting the knob on the buzzer from one end position to another and typing, but there was no sound coming out of the buzzer.
Edit: I just probed the pins on the controller header and it seems that indeed 5V and GND were switched (and DVR wrongly connected). I rotated the cable connector and connected it back to the header, but still no sound :/
I also probed the buzzer controller and got the following (pic for reference; same color denotes same potential)
- when DVR is 0V (to GND), output of green pin on the controller is around 0.55V
- when DVR jumps to 5V, output of the green pin on the controller is around 0.62V
- on the resistor that connects green trace and orange trace there is never any voltage measured, so the orange is always following the green
- three pins below the trimmer are always on the same potential, two of them go to the buzzer, and one I guess is connected to that orange trace, because voltage also follows orange/green trace