Radar problem - old furuno 1730

[snowbird30ds]

I have a problem with my oldfuruno 1730 radar, I know it's ancient and should be in a museum but up untill last season it was working fine and for the sort of trips I do I'm not spending out on replacing it
It's fine for about an hour then I start to get spurious lines radiating out from the centre building up till I can hardly see anything else, I have looked inside the radome and display unit and can't see any obviously hot spots and all connections look to be clean and free of corrosion, I can't think of anything that has changed around the boat electrically, the heatsik on the back of the display did seem to be getting very hot last summer but I never checked it before so that could just be normal (it is a heatsink after all).
I've played with the adjustments on the front panel and nothing clears it.
Any ideas greatly appreciated.
If I can't get it to play nicely I'll junk it and rip the guts out of the radome and fix my tri-lens radar reflector inside and do without but I'd rather fix it if it's viable.
Links below to piccie and video of the screen messing about.

Screen piccie

Screen video

 

[Hoolie]

My first guess would be a scanner problem. Can you acquire a cheap replacement, as you say they're pretty old now? It would certainly be better than a reflector and you wouldn't have an empty space where your display is currently

 

[david_bagshaw]

my take would be connections to scanner, particularly the grounding wires

 

[pvb]

Obviously check the scanner connections, but it may be electrical interference caused by wear on the slip ring assembly in the scanner. This handles the power to, and the data from, the rotating magnetron. Spraying contact cleaner on it might help, but you'll really need to get the scanner down to deck level to do any serious work on it.

 

[snowbird30ds]

Thanks for the ideas guys, a few things to check.

 

[jiris]

I am not sure if these symptoms fit the picture, but one of the most common problems plaguing old radars is the shielding in the radom-display cable. It is very likely when you cut the plastic cover of the cable, you find just a white or green powder where the shielding mesh used to be. Often replacing the cable sort out a lot of problems.

 

[DaiB]

You could contact Furuno on the main website "contact". I had a problem with the same radar and they then sent "my case" to Furuno UK who contacted me and gave me fault finding details. They were very helpful.

 

[boatmike]

You could contact Furuno on the main website "contact". I had a problem with the same radar and they then sent "my case" to Furuno UK who contacted me and gave me fault finding details. They were very helpful.

I could not agree more. The first stop for questions like this should always be the manufacturer. Its always assumed that with older kit they wont be helpful. In my experience they often are with the possible exception of Raytheon who I have always found significantly unhelpful with the standard reply. "Its obsolete buy a new one"

 

[snowbird30ds]

Have to admit I'd assumed furuno wouldn't care so not contacted them.