12-01-12, 06:04 PM
Servo motor failure is rare so don't go down that route just yet. 
If it does require replacement, it lives on top of the motor towards the front left side, just inboard from the frame. A bit fiddly to get at but not a major task.
Overly-tight or incorrectly fitted cables will cause 7k error codes even if the valve itself is fine. I've known a few where the cables have been installed the wrong way round, too.
Another possible cause is the valve binding when the end plate is tightened up. This happens because the valve spindles are very slightly out of line. It doesn't take much resistance on the cables for the servo motor to stop working ... it does this to protect itself from burning out.
With the cables and pulley removed, can you flip-flop the valve easily using just thumb and forefinger on the spindle? If you have to apply any effort to rotate the valve, you'll need to dismantle it again to determine why.
Misaligned spindles can be straightened with care. Not a job for the ham-fisted home mechanic, though.
If it does require replacement, it lives on top of the motor towards the front left side, just inboard from the frame. A bit fiddly to get at but not a major task.Overly-tight or incorrectly fitted cables will cause 7k error codes even if the valve itself is fine. I've known a few where the cables have been installed the wrong way round, too.
Another possible cause is the valve binding when the end plate is tightened up. This happens because the valve spindles are very slightly out of line. It doesn't take much resistance on the cables for the servo motor to stop working ... it does this to protect itself from burning out.
With the cables and pulley removed, can you flip-flop the valve easily using just thumb and forefinger on the spindle? If you have to apply any effort to rotate the valve, you'll need to dismantle it again to determine why.
Misaligned spindles can be straightened with care. Not a job for the ham-fisted home mechanic, though.