Perhaps I have been very lucky in that my dock has never failed, even after 75,000km of use on my VStrom.
On a rare occasion, it doesnt make full contact, and all I do is pull back on the spring loaded part and let it "snap" into place. I have always kept a light layer of dielectric grease on the contact areas.
You can tell if a positive connection has been made when slipping the device into the cradle a few of ways.
1. If you place the unit into the dock with the unit turned off, it should turn on by itself. If it doesnt, do as above.
2. If at any point while the bike is moving you can access all of the menu's (touch the screen), you know you are not connected, do as above.
3. If after some time in use, touch the satellite bar and see the battery symbol in the upper right corner.
This happens so rarely on mine that I have not been concerned.
If you suspect that your cradle is not working, I suggest cleaning the contact pads and pins, and applying a light layer of dielectric grease.
If you happen to have a dock that does not work for sure, I would be very interested in getting ahold of it and disassembling it for testing and perhaps come up with a repair for it. If anyone is interested in sending me their old one (probably wont get it back...), let me know and we can work something out. I would gladly pay for the shipping.
Cheers!