Sweeney
Administrator
Since my part is due to arrive today, I decided to disassemble or autopsy if the part doesn't fix the problem.
Disassembly looked horrible -- but turned out to be quite easy. The way the CF35 is assembled appears to be to bolt all the metal parts together, then to spray into the void expanding foam. The two plastic hemispheres that make up the box are effectively welded into place by the foam. These fridges are remarkably simple...
There are to major electronic components - and without a technical manual there is an upper and lower control board -- the lower control board looks primarily like a power supply regulator/regulator and motor control. It is located in a black box attached to the chassis for the compressor.
The upper control board is by the display. All of the "brains" are up top by the display. Two screws hold it, then 3 internal screws for total disassembly. Two connectors are used, a ribbon cable to the Lower Control Board and the thermistor are both socketed. Nice. Soldered connections at these points are a sure way to grind my gears.
A bit off topic, but the upper control board looks well made - The switches are tac switches which give a nice click and in my experience work well for quite a while - I don't expect them to give problems, but if they do --- easily repairable with a soldering iron, and a few minutes. The 8 segment LED theoretically is replaceable as well. I plan on replacing mine with a white one - the green is just far too dim to see in the sunlight. This has always been the weakest part of the overall customer experience with the Dometic.
Once you unplug the thermistor (2 connector socket) the wires drop down and through the compressor cabinet, then on to an entry point to get into the foam in the cabinet. Its a black tube with wires inside, and it runs to the side opposite the lower control board. 2 strain reliefs, and a glob of silicone.
The first review document and video's I saw showed separating the hemispheres and chipping away at the foam a TOTAL mess. And what I started to do before I realized it was futile to think the hemispheres would separate. Spray foam is a very good glue. For my model this was entirely unnecessary. I needed only to remove the strain relief screws and pull on the "gummy" silicone sealant plug and the thermistor pulled directly out.
Sadly so did in addition to the thermistor water poured out. Not a lot...just a teaspoon. Its safe for me to assume that the cause of death for the thermistor was water infiltration, which would explain why it failed and after not being used for a year started working again.
Steps to facilitate the repair:
1] Remove the 2 screws holding the upper control board housing in place.
2] Remove the 3 screws holding the UPB to the housing.
3] Unplug the themistor.
4] Remove the screws holding the compressor cover - It is obvious, there are about 9 or 10 small screws around the shell piece that has the vents.
5] follow the thermistor wire, through the compressor cabinet to where it enters the freezer chest area, removing the strain relief screws and any fasteners.
6] gently tug on the silicone plug, onee removed the thermistor should slide out of the shell half very easily.
Reassembly is the inverse. I will be adding a big glob of thermal grease on the new thermistor - needs to be there anyway for temperature detection, hopefully some fresh thermal grease will help prevent the new thermistor from falling. I don't see this as a long term fix - one part failed, the second eventually will as well. But its cheaper than a new fridge.
Level of difficulty is difficult to assess due to experience and aptitudes. As some one who can change his own brakes, oil, and keep an lawn mower from running without the help of a repair shop --- easy job. If your'e not sure which end of the hammer you use to drive a screw....forget about it.
Tools needed: 2 screwdrivers - #1 and #2. Some of the screws were a little fiddly.
Supplies needed: 1 replacement thermistor available on eBay, Silicone sealant, thermal grease - I used the same as they use for CPUs in computer assembly.
I'm waiting on the part to arrive. The thermistor that came out does show resistance changes to temperature, but I don't know wha the values should be --- and reports 80 degrees when dipped into ice water....update to come.
OP: Sorry, kind of hijacked this --- I've got a bad habit of doing this.
Disassembly looked horrible -- but turned out to be quite easy. The way the CF35 is assembled appears to be to bolt all the metal parts together, then to spray into the void expanding foam. The two plastic hemispheres that make up the box are effectively welded into place by the foam. These fridges are remarkably simple...
There are to major electronic components - and without a technical manual there is an upper and lower control board -- the lower control board looks primarily like a power supply regulator/regulator and motor control. It is located in a black box attached to the chassis for the compressor.
The upper control board is by the display. All of the "brains" are up top by the display. Two screws hold it, then 3 internal screws for total disassembly. Two connectors are used, a ribbon cable to the Lower Control Board and the thermistor are both socketed. Nice. Soldered connections at these points are a sure way to grind my gears.
A bit off topic, but the upper control board looks well made - The switches are tac switches which give a nice click and in my experience work well for quite a while - I don't expect them to give problems, but if they do --- easily repairable with a soldering iron, and a few minutes. The 8 segment LED theoretically is replaceable as well. I plan on replacing mine with a white one - the green is just far too dim to see in the sunlight. This has always been the weakest part of the overall customer experience with the Dometic.
Once you unplug the thermistor (2 connector socket) the wires drop down and through the compressor cabinet, then on to an entry point to get into the foam in the cabinet. Its a black tube with wires inside, and it runs to the side opposite the lower control board. 2 strain reliefs, and a glob of silicone.
The first review document and video's I saw showed separating the hemispheres and chipping away at the foam a TOTAL mess. And what I started to do before I realized it was futile to think the hemispheres would separate. Spray foam is a very good glue. For my model this was entirely unnecessary. I needed only to remove the strain relief screws and pull on the "gummy" silicone sealant plug and the thermistor pulled directly out.
Sadly so did in addition to the thermistor water poured out. Not a lot...just a teaspoon. Its safe for me to assume that the cause of death for the thermistor was water infiltration, which would explain why it failed and after not being used for a year started working again.
Steps to facilitate the repair:
1] Remove the 2 screws holding the upper control board housing in place.
2] Remove the 3 screws holding the UPB to the housing.
3] Unplug the themistor.
4] Remove the screws holding the compressor cover - It is obvious, there are about 9 or 10 small screws around the shell piece that has the vents.
5] follow the thermistor wire, through the compressor cabinet to where it enters the freezer chest area, removing the strain relief screws and any fasteners.
6] gently tug on the silicone plug, onee removed the thermistor should slide out of the shell half very easily.
Reassembly is the inverse. I will be adding a big glob of thermal grease on the new thermistor - needs to be there anyway for temperature detection, hopefully some fresh thermal grease will help prevent the new thermistor from falling. I don't see this as a long term fix - one part failed, the second eventually will as well. But its cheaper than a new fridge.
Level of difficulty is difficult to assess due to experience and aptitudes. As some one who can change his own brakes, oil, and keep an lawn mower from running without the help of a repair shop --- easy job. If your'e not sure which end of the hammer you use to drive a screw....forget about it.
Tools needed: 2 screwdrivers - #1 and #2. Some of the screws were a little fiddly.
Supplies needed: 1 replacement thermistor available on eBay, Silicone sealant, thermal grease - I used the same as they use for CPUs in computer assembly.
I'm waiting on the part to arrive. The thermistor that came out does show resistance changes to temperature, but I don't know wha the values should be --- and reports 80 degrees when dipped into ice water....update to come.
OP: Sorry, kind of hijacked this --- I've got a bad habit of doing this.