1623 Radar cutting out in choppy seas.

I've been running a 1623 radar in my boat for 4 years now. Two seasons back, the unit began experience problems. It works fine in calm conditions or at the dock. As soon as the boat takes a hit or is in choppy conditions, the unit fails. The screen will get lines, zig zags, fuzz out, whatever you want to call it and cut out, powering off. I am often able to re-power the unit on and it will work until the next smack to the boat. Sometimes it powers itself back on but still has to go through the start up process. In foggy conditions, it's not a good situation.

Last winter, I sent the head unit to headquarters in WA for evaluation. They said they put the display through rigorous vibration testing and every other test they could think of and could not reproduce the problem. Hence, the head unit appears to be fine. While the problem could be with the dome, the tech rep and I both agree it's not the likely culprit. So I'd like to hear any of your ideas or thoughts and want to know if anyone else has experienced similar problems and/or found solutions. I'm leaning towards replacing the cables, both data and power but i'm looking at a ridiculous price of about $200 shipped to accomplish this task. It may be the power cable alone.... I don't know.

Any advice is appreciated.
Thanks

Monomoy
Intermittent problems are the hardest to pin down. Since the unit is shutting down, I would guess the possible items....
1. Power cable
2. Scanner motor worn/weak stalling and causing a short; resulting is display shutdown
3. Scanner cable intermittently shorting. (Check any junctions/splices)
If your unit was sent to the Furuno USA service center, I am sure they updated your software while it was being checked out; but check your software version anyway to make sure it is within the last two recent versions.
--disclaimer-- there are many things that could cause intermitting shorting including items in the scanner / water / etc...
Let us know how it turns out when you get it pinned down.

Thanks for the input. I'm going to start with a new power cable and go from there. I'll update this down the road once I get a chance to test it out.

Update: toggling the power cable connection at the back of the head unit reproduces the problem. The wire and connector appear fine, but clearly the connection is an issue. Despite Furuno having tested the head unit, I don't know if the power connection was manually toggled, hence, I don't know if the problem resides with the connector or the head unit side of the connection. Would anyone suggest a remedy or pin adjustment? What about a di-electric grease? Or replace the power cable ($60)?
Any input is appreciated.
Thanks

The grease would provide little to no help. I would recommend trying a new power cable and ensure you maintain proper strain relief of the cable.

I spoke with Furuno yesterday. A new power cable is on a UPS truck somewhere on its way from Washington state.