Raymarine SL72 plus no image returned on display

[SV_Island_Fever]

I acquired a used SL 72 plus and am having trouble getting it to work. According to the previous owner it was never fulling installed on their boat. I have replaced the r126 flat molex connector that connects to the scanner because it had loose wires and gave me the "scanner Not Responding". Once i replaced the molex connector, that problem was solved. Continuity check on the cable confirms it is good. Shield on the cable is very rusty. Not sure if that is an issue. The scanner rotates. The display works. I ran the hidden diagnostic and all functions passed.

However when I transmit the screen shows no returns. I found a tip on the web about adjusting the gain manually. My screen stays clear till I get to 92+ then it starts to go black. According to that check, the cable has an issue. I have checked it multiple times with the same result. Before I buy a new cable, I am hoping someone can help..

Thanks,
S/V Island Fever

 

[Bill Roosa]

The shield is an important "wire" If you get an open between the components that the shield grounds together you get what is called a floating ground. The actual signals that the unit receives are similar to what you would find in a VHF antenna coax when receiving. Not much voltage and with no ground ........ and the diagnostics say there is a problem with the cable....

 

[SV_Island_Fever]

Thanks for the input. Turns out after I removed a couple of feet off the end, it now works. I guess corrosion to the shield on the video was the culprit.

 

[Bill Roosa]

99.44% of all electrical problems on boats are corroded connections!