[TG] [TG11] RL80C Plus system - all functions work but not at both MFDs

[Tom - Raymarine - Moderator]

Hello Bob,

Standard navigational info (depth, speed, wind, GPS etc.) goes through low-speed Seatalk. Graphical type connections (radar, chart, sonar) go through the higher-speed HSB2. The fact that the pilot works from both displays shows that your Seatalk network is ok, your problem is with your HSB2 network.

The HSB2 cabling was very prone to poor contacts on the push-in, hard-rubbery connectors, which is why we've gone away from that connector type in all more-recent designs. The simplest explanation is that the cables aren't making a good contact any more. They're simply crimp spade terminals over-moulded with rubber and were prone to splaying out over time and fitting/removal. Try running another bit of 3-core cable with 3.2mm (1/8") crimp terminals and see if that makes a difference.

If one or both of your displays are HSB2/Pathfinder Plus hardware (not a given: it was possible to upgrade non-Plus hardware to partial HSB2-compatibility through software, and we offered replacement decals that said Plus...) then you'll external network terminators piggybacked in the back of the displays. The connectors on these are also suspect, as above. Each terminator had a resistance of 120 ohms between the active pair (the two pins side-by-side) so if you suspect one, try adding a resistor of that value across the back of your crimp terminals.

If neither of these makes a difference then you've probably got a failed ARCnet transceiver chip in one or other display. These were prone to static damage. On Plus hardware (the surest way to tell was the logo on the splashscreen at startup, Raymarine generally meant HSB2, Raytheon always meant HSB1) you could get some idea whether this was the case or not by the resistance on the active pair of pins in the back of the display, with the terminator removed. My memory was that approx. 2kOhms was healthy something like 20kOhms meant a failed chip. If you measure ~120 ohms you're measuring a terminator: either inside (HSB1 hardware) or still plugged in externally. Measure with power removed.
If the ARCnet chip has failed then that's probably final, I'm sorry to say - we don't have the component or PCBs any longer for repairs, the displays are too old for that.

Regards,
Tom