B & G 390 System - Log Calabration Question

[Spirit28]

Any one out there still use a B & G 390 system?

I want to check the calibration for the log & been over the measured mile a few times & worked out the correction factor. I want to enter this into the system, however when I follow the instructions in the manual & press the "shift" key to envoke the calabration section, the MDU goes blank (MDFs stay on...), I press "shift" again & the MDU comes back to life. It is like the MDU is going into a sleep mode or something. I can't find any mention of this in the manual.

The control unit for the depthsounder behaves in the same way so I don't think there is a fault with the system.

Any clues?

Thanks

[Sandero]

I don't have the 390... but perhaps you have to wait holding the key. I know on the Hornet and the Hecta when you change a calibration value you have to hold the key for the data you are trying to change for about 10 seconds before it takes.