My Raymarine st4000 beeps and says: NO DATA when I want to go to AUTO mode.... cannot calibrate.. what's wrong?

SOURCE: my st4000 mkII shuts off from auto mode whhen i

CHECK THE POWER SUPPLY WIRING ,If it worked before ,could be corrosion or lose wire connection,or terminal bad crimped,or terminal loose inserted.
If it is new installation ,power wires could be undersized,or battery discharged .
Normally autopilot shuts off from auto and restarts when power supply voltage drops under the reset voltage ,when the wheel turns ,the motor current increase and the power voltage drops when the power supply wires are not OK.

SOURCE: Where can I purchase the

Search in e-bay ,there is a supplier

SOURCE: clutch lever drops out by

There is a screw that hold the lever.If that screw gets loose the lever gets loose and drops down when get jerked or passes through bump. A short loop of chord around handle and drive housing which seems to do the trick.----------- Open the round cover and have a look.If the belt looks worn out it also needs to be replaced.check the tension of the belt as it is an "over center" clamp so should stay engaged even without the aforementioned bump.If the belt tension is loose then it has to be made proper tight ,if its got worn out then it needs to be replaced. ------------- There are many other ST 4000 Ray-marine users facing the same problem:--- some users mentioned that they attach a small length of elasticated cord to the binnacle (like thin bungy cord) and this blocks the lever from dropping by itself or getting disengaged. ------------- In some other cases,this was the reason of problem:--- Read as follows:--- The lever moves a cam that tensions the belt. The pin that locates the lever position relative to the cam gets corroded. This cause the cam-position-to-lever-position relationship to change slightly which means that the lever didn't quite positively lock (due to the belt tension on the cam). If this is the case in yours then it can be fixed temporarily with a handy bit /nail or drill bit of something to take the place of the pin until you could get a new lever and cam assembly.--------------- This troubleshooting will help.Thanks.Helpmech.