tkbowers Report post Posted December 8, 2015 My Dometic refrigerator, model RM3762RBX purchased August 2011, stopped working. I woke up this morning to error code EO (No communication between display and power module). I have verified adequate voltage at the unit, plus ground connections and fuses appear to be good. Three conductors (brown, black and red) connect the display and the power module. My next step is to test resistance of these conductors. If that checks out okay, I'm planning on ordering a new power module ($200) and/or display ($120). I could just order the power module first and see if that corrects the problem. Something tells me that component is more likely to fail than the display. Suggestions? Does my thought process make sense? My local RV repair person charges $30 to show up and $100 per hour. I assume he marks up for parts too. Experience has taught me that costs escalate quickly whenever I hire "pros" to work on my motorhome. Thank you. Tom 1994 Foretravel U-240 Share this post Link to post Share on other sites
obedb Report post Posted December 9, 2015 I am surprised that the really knowledgeable members haven't responded. A 2011 Dometic is new enough that no opinions exist? Swapping parts can get expensive as most all DIYSers know, but the power supply does seem the likely culprit. Perhaps a call to Dometic would be helpful? Let us know what you find out. Share this post Link to post Share on other sites
tkbowers Report post Posted December 9, 2015 Dometic claims that they do not have a tech support group and referred me to my local service centers. If one is to believe the error code, the problem should be either the display, the power module, or the cable connecting them. I tested the cable and all three conductors checked out okay. Share this post Link to post Share on other sites
elkhartjim Report post Posted December 9, 2015 I copied this word for word from another forum, hopefully it will be beneficial. "This error means that the control board is not getting communication from the eyebrow board, which is the display board at the top. On the back of the fridge you will find the main fridge control board, which is protected by a black plastic cover. Remove this cover and you should see the board. Approximately in the center of the circuit board, you will see a terminal marked D+, which should have a wire coming out of it. This is the power wire to the eyebrow board. If this wire is even a little loose, or the wire is loose in the connector, you could easily get this error. Please check that connector to make sure it is tight on the board and the wire is tight in the connector. To the left of this connector, on the left edge of the board at the top, is the communications harness going to the eyebrow board. Also check this connector to make sure it is secure on the board.If this still doesn't solve your problem, go back inside the coach and carefully remove the top panel where the display and control panel is. Inspect the connectors coming into the eyebrow board. If they are secure and undamaged, you will probably have to replace the eyebrow board. However, before doing this, it is probably a good idea to have the main board tested, as that could also be the problem. If you remove the main control board at the back of the fridge, you can take that to your local RV service center where they will be able to test it for you. If the main board fails, you need to replace it. If it passes, and you have thoroughly checked the connections, you should replace the eyebrow board.Also, just as a sanity check, test the voltage coming into the fridge to make sure it is close to 12V. Also check the fuses on the board to make sure they are okay." Share this post Link to post Share on other sites
wolfe10 Report post Posted December 9, 2015 Tom, Just got this from our FMCA Technical Advisory Committee expert on absorption refrigerators. Between this post and Jim's excellent post, you should be able to narrow it down a little: Unfortunately the fault could be with the cable, it could be the display or it could be the power module or a long shot it might be the plugs. Look for corrosion, a pushed back pin that is not contacting. etc. and from there it is just a trial and error solution. I would definitely ohms test the cable as you have suggested. If the cable is OK I would try replacing the display as it is easier and cheaper and last the power module. Good Luck Share this post Link to post Share on other sites
tkbowers Report post Posted December 10, 2015 Thanks everyone! The cable checked out okay using my ohmmeter. I'll keep you posted. Share this post Link to post Share on other sites
tkbowers Report post Posted December 28, 2015 I would like to update everyone on my refrigerator issue. Last week I ordered a replacement power module ($229) and installed it yesterday. I started the refrigerator and let it run overnight. It was still running when I checked it this morning, so I think my problem is solved. Thanks again for your help! Tom 1994 Foretravel U-240 Share this post Link to post Share on other sites
wolfe10 Report post Posted December 28, 2015 Excellent. Thanks, Tom for updating us. Share this post Link to post Share on other sites