Radar Troubleshooting

[Reefmagnet]

Hi All. Our boat has an ancient JRC 8Nm range radar that isn't working properly. The screen blacks out unless the rain clutter function is activated. With the rain clutter function on, I can adjust the unit for a legible display for the lowest - 0.25 Nm - range, but can't get any sensible display for higher ranges - only speckles and clutter. I'm thinking that maybe bad bearings on the radome unit could cause this problem? Anyone able to take a stab at this or other possible causes? Cheers.