melon

Shield Pro is a super solid device, handles everything I throw at it. Have also gone through a few cheaper devices but they come up short in one way or another. But the Shield is still going strong after about 5 years of heavy use. If you’re going to spring for a shield, I’d get the pro. It has more connectivity options and more memory.

Hmm, very interesting suggestion. I have done a bit of soldering many many moons ago, tinkering around with my uncle. Probably have got his old iron kicking around here somewhere. I'll call the shop back and ask for more info - eg are they replacing actual components or is there just something loose. I don't have the board here with me to inspect unfortunately.

I took the circuit board down to a module repair service to be tested for $45aud. They gave my quote today after testing, of $272aud for repair. He says that the power supply is gone on it. He's not able to give me a warranty on the repair, or do a full test because I only took the circuit board in, not the whole appliance. Also noted that he has repaired this same issue plenty of times before, and is quite confident this will resolve the issue. So I'm a bit hesitant - on one hand, I could purchase a second hand 3-way fridge for same or less. But condition would be unknown. I could also purchase a new compressor fridge for not much more cost, but I'm concerned that the noise would drive me bonkers. With all due respect, I'm quite sure that it's nothing to do with my wiring. DC/DC, MPPT, solar (changed wiring from parallel to series on my fold out panel), anderson plugs, fans, lighting, usb ports, water pumps, shunt, blade fuse holders, terminals - all installed from scratch by me and all working perfectly with no blown fuses or heating wires or excessive voltage drops or any signs of any issue. I guess I'm just concerned that some unknown factor (other than age) has caused the issue, and that it might reoccur.

Based on the above, do you have an inkling as to what the problem might be? Or is it still too hard to tell? Repairing or replacing individual components on the circuit board is clearly beyond me, so if we can say that almost certainly the circuit board is bust, I might need to start working on the “new fridge fund” 😅 But if there is a chance that it might still be a serviceable component, I’m more than happy to continue on this journey.

I'm using this model multimeter - https://www.amazon.com/UNI-T-Multimeters-interface-Backlight-Temperature/dp/B01LXXHJUX I removed the fuse when I tested it. Will get a new one for testing asap. There is 13.2v reading at the terminal block, and at the violet/black wires where they are connected to the circuit board. I'm not sure yet how to test voltages across the circuit board - when i hold one tip of the meter to the negative post on the terminal block, then hold the other tip at various points across the circuit board, most points read 13.2v. Except some points on the very right hand side, where the reading drops down to 4 or 5v. I don't have a clue if that info is useful or not. Plan is to test with a new fuse, and if it's still no good, then I'll get in touch with a caravan fridge repair company to ask for a quote on testing the board. I'm just really hesitant to pay for testing if there is a way that I can tell for myself, yes this board is stuffed. I called a couple of companies today, and unfortunately this circuit board is discontinued. Thanks again for your help.

OK sure, I will do this and report back. The 12v ignition is wired to a 'battery eliminator' 12v power supply, that's connected to 240v shore power. With 12v supplied to the ignition wires (even if it's not also supplied to other 12v power circuit in the fridge), the control panel would (previously, before all this unpleasantness) light up fine and let me run via either gas or 240v. The other 12v power circuit is wired to the trailer plug - so currently has no power as the van is not hooked up to my car at the moment. Current situation is, even with 12v being supplied to the ignition circuit (tested both via battery eliminator, and a newly installed leisure battery that is running a few other 12v circuits perfectly), nothing on the control panel is lighting up - switching to gas does not trigger the ignition sound, and switching to 240v does not cool the fridge.

Thanks for your help so far! I've borrowed a multimeter, and tested the fuse that's located directly on the circuitboard I posted in the OP. It's measuring 1.6 ohms, and google tells me this is good. The fridge is not using a battery at all now, as per the earlier instructions to take the wiring back to what it was originally. There is a 'battery eliminator' 12v power supply that's plugged in to shore power, this is where the fridge gets its 12v for the ignition circuit from. There is currently no 12v power input (van is not connected to a car, which is where this is wired to), and the 240v plug is unplugged for safety while the circuit board is exposed. Now I'm taking another look at the schematic to see where I should be poking this thing to get some useful readings 🤓

I would really love some qualified help, but unfortunately I just can't afford it. That's why I'm trying my damnest to figure out what component might be shot so that I might have the chance of replacing a small component rather than having no fridge all summer. I do apologise for my lack of knowledge, but am nothing if not persistent and with some kind and generous help I'm sure I can at least save myself paying a diagnostic fee just to be told that the whole thing is wrecked and should be put in the bin. Unfortunately I don't have a proper multimeter, just a little device that tests for the DC - it displays either low (under 5) medium (5-10) or high (12). When I said active current, i just mean that I got live readings from all of the points I tested on the circuit board. I can't remember if they were all 12 or not. Would a reading under 12 indicate an issue with that particular point?

I'm struggling with this a bit sorry I've checked all the points on the circuit board where the wires come in, and most of them are displaying active voltage. Are there any specific points where I should be testing? And how will my multimeter display anything (ohms?) if I turn off all of the electric supplies to the fridge?

OK he's all hooked back up to the original wiring method, and I'm still getting the same symptoms. No lights at all on the control panel 😢

Yeah that's very perceptive, very good advice. I moved the violet/black gas ignition wiring to the battery first (before moving red/white over), and had that running for a day or so with no issues. The issue only started when I moved red/white over to battery as well. I have since moved red/white back to orig, leaving v/b on battery, but have not returned to what was a working situation. My next step is to move v/b wiring back over to orig as well, but I do doubt that this is the problem unfortunately.

My fridge has no power, nothing lights up on the control panel. Was working fine on 240v and gas. I'm in the midst of adding a battery and doing some rewiring - I moved the 12vDC input (red/white, not the violet/black ignition) over from what I assume was trailer plug wiring to a terminal on my battery fuse block. I think it may have fired up for a second when I turned the fridge switch over to 12v to test (can't be 100% sure, but I think I remember seeing a spike on my battery shunt monitor), then everything just died. Nothing lights up on the control panel at all now. I've tested the fuse on the back of the control board, it's fine. This thread brought me here when going down the google rabbit hole - https://www.rvnetwork.com/topic/122661-dometic-fridge-has-no-power/page/4/ - and while it's got lots of great info, I'm just wondering if anyone could help with some more specific troubleshooting or point me to a service manual (can only find user manuals for my model)? I'm a novice with a multimetre, but I can see that there is power getting up to the control board - If I hold the red thingy from the multimetre to the point on the orange arrow in the pic below, then turn the dial to ignition, then the LED lights up (but no clicking sound of ignition). If I move the dial down to 12v then that LED lights up as well. Really appreciate any help here, I've gone just about loopy getting to this point!