2011 Raymarine Radar kaput...gradual process...I will describe it...

Just a followup that in the end my problem was related to apparent breaks in both the data and power aspects of the original cable. This, in spite of Raymarine techs telling me via the symptoms that almost certainly was NOT the issue and my own ohmeter tests between the beginning and end of the power cable showed excellent continuity !

I recently installed a new cable (major PITA due to the routing, overkill numbers of wire ties, tight spaces to get in,etc) and now, finally, the radar works properly every time.

Since I used the old cable as sentinel to pull the new cable I was able to get a good look at all of it and damned if I see a thing wrong with it physically. Quite the mystery, but somewhere in the cable, there must have been a manufacturing defect that took a while to show up.

The Raymarine techs, one in particular, were very nice folks however, and quick to check the unit out when sent in (twice !)...no complaints there.

Cable problems are the most difficult to troubleshoot and sometimes defy logic. What shows good in a static test with a volt/ohm meter does not work when you actually try to use it. One technique we use in the field when we are troubleshooting a suspected cable problem is to have a set of eyeballs on a display while someone shakes everything from one end of the cable to the other. When you consider the data signals from the radar to the MFD are based on two voltage states, when one or both of those states is operating close to the lower voltage limit, a small increase in resistance could turn a 1 into a 0 or vice versa and all of a sudden you have no data, or the logic says the antenna is not turning.

Glad it is solved. File this in, if everything else checks good it is probably the cable. Murphy is alive and well, the repair that takes the longest will fix the problem.

Tom

I've seen this with electronics enough that I am always suspect of it being the possibility. Now when it happens with an HDMI cable it's very easy to switch and check. Not so in your situation.