Problems with 4kw analog radar

[bobs]

My radar in combination with a RL80C display is giving me some headache lately. I' ve been getting the terrible message " scanner not responding " .
So first of all I would like to perform a display resistance test the way Raymarine describes.
Meaning measuring the pins of the radar connector going into the display to see if the fault is not in the unit itself
Question is , should that be done with a display that is powered up , switched on that is ?

Thanks

[GordMay]

Resistance tests (Ohmmeter) are ALWAYS performed with power OFF.

[bobs]

Yesterday , 5 years after my initial post I was able to solve the problem .
My radar was there in the mast doing nothing and the last few weeks I was playing* with the idea of taking it off permanently and bring it home . Take some useless weight from the boat .
As a last try I took it down yesterday and pulled the cable out of the mast . I dismantled the unit completely and found some oxidation on one of the prints , but more important , I noticed the pins , male and female , of the flat cable connector had serious oxidation also .
Some wires just broke off from the connector and that gave me some hope to revive the unit .
After soldering solid wires to the 8 pins inside the radar so I could get rid of the fragile flat raymarine connector I re-configured the connection between cable and unit with a different type of connector .
Once set up it was time to give it a try , guess what .
I now a full operational system again , so there was nothing wrong with the plotter nor the radar unit itself , just a case of bad electrical connections
5 years , good thing come to those who wait .

Regards