Okay, I finally jumped in and began testing. I had been manually defrosting for many years, once every few months, more in summer. Tip #1, no need to take apart freezer compartment stuff if it’s the defrost timer in the upstairs area! Thank you for showing me how I could spin it manually, without even taking it out, because I did so and heard the click, then I touched the heater element and burnt my finger! Ouch! But that tells me that the defroster terminator (aka temperature sensor, which is so hard to get to) is functional, as is the heater element itself. So, now I can purchase a new defrost timer. And see how it functions after that! Hopefully that’s it. Thanks again so much for the great video!!!

@PIFDIY

24 күн бұрын

Thanks! Yup, sounds like you might have lucked out with a bad defrost timer. Much quicker repair!

Thank you for your video, it was very helpful. I've successfully replaced my sensor and conducted a test.

@PIFDIY

4 ай бұрын

Good job! Glad it helped!

Well done MacGyver.

Excellent DIY video. I have the same model and it suddenly went "dark". No interior lights and nothing cooling. I found the main power switch "smoked" and the four terminal connectors singed. I jumpered around the switch and now the freezer is working fine but the refrigerator side is not cooling. I tested the cold control and it is OK. The fan in the top of the refrigerator side is working. Service tech says it needs a new control board for $1400 and $200 to install it. I can buy a new control board for $650 or a remanufactured one for

I too have a Sub Zero 590 model. I have been through this exact process. For me, the symptoms manifested by no ice being made, which is because of the freezer temp not getting cold enough. You pointed that out in your video. Yep, when you exposed the coils in the condensor, they were fully covered in ice and that is the problem. I have replaced both parts you replaced as well. What a PITA this was to replace. I ended up setting up mu Android device running Zoom w/camera on to a laptop also in the Zoom session with laptop in freezer (and lots of light) to see more of what I was doing. Anyway, that was 2 years ago. I now routinely do a few "maintenance tasks" a couple times a month and one task weekly. 1. I clean out the ice bin. We use a lot of ice and this bin and the process of moving the ice through the shoot leaves a lot of ice shavings. So, I pull bin out, dump ice out of ice bin into large bowl, use hot water to melt all shavings/ice, dry bin, and replace ice and put bin with ice back into freezer. 2. I now have a flashlight close by and pull the ice bin out weekly and look closely at the coils/condensor to see the level of icing. Occiously, it should not have much ice. I do this as I have had this symptom return twice since the removal/replacement of the discriminater part. Long story short, I found that large swaths or chunks of ice had formed in the back of the condensor area where the discriminater part is, in addition to seeing all of the coils iced up. What must have happened is that the ice in the very back was enough or formed against the electrical connector on the discriminater to lose continuity. Very weird, unique, and hard to find. I summize the cause was the freezer door being left open slightly over a week or so (my wife and I were out of the country for three weeks and my daughter stayed at our house). Summary, I watch for frost weekly as I know what normal looks like. Yesterday, I found significant icing. Not sure why yet. I removed the light cover, the white panel with the 4 screws, remove the ice bin, remove the 3 screws on ice maker, remove cable to ice maker. Nothing else (well all of the food gets removed to another freezer). I then accelerate the defrost with a variable temp heat gun, ensuring the air temp is not too hot. I defrost the condensor and also left the heat gun in a position to blow warm air behind the condensor. Ithen turned freezer back on, let it get to 10 or so degrees and manually moved the Thermostat timer to force the coil heater to com on. It does. I know (this am) have the ice maker and bin back in, but am leaving the white panel and light cover off to watch the behavior over the next several days. I don't know why this happened this time.

@PIFDIY

4 ай бұрын

Hmmm, so it seems like everything is working as it should but you still get occasional ice buildup? I'm wondering if it's related to the defrost timer? Maybe it skips a cycle intermittently? If so, maybe when it does go into defrost, it doesn't have enough time to remove all ice/frost? I'm not certain, but the 1st gen 590 OEM timers may have been 8 hr units. The replacement I bought on Amazon was 6hr. My thought was that more cycles will just ensure no ice buildup, even though it shouldn't really be needed. Not sure but worth looking at...

@Mark-ji5ve

4 ай бұрын

Good idea. I am in watch mode now. Temp being watched and I am manually moving the Thermostat timer with screw driver ro force defrost. Update from this afternoon. All is working as expected. I will leave the freezer inside panels off for a few days and inspect.

@PIFDIY

4 ай бұрын

Ok, so you're testing the timer to see if it initiates and comes out of defrost every 6 or 8 hours (depending on the part that is being used). Defrost cycles can be up to 20 minutes, as far as I know. You could probably set a timer for yourself to check at those intervals. Good luck! @@Mark-ji5ve

@Mark-ji5ve

4 ай бұрын

@@PIFDIY and others. I am at ~ 5 days now. Light cover and cover in Freezer that exposes the condenser has stayed removed for the purpose of looking at the icing amount of the condenser coil icing. All is working as expected. I have manually tested the defrost timer (using screw driver to move the timer manually) and see/feel the heat element heating (touch carefully) and watch the frost/icing melt. Both the parts (timer and discriminator), as I have mentioned have been replaced in past 18 months. The guy I know I talked to and bought parts from (at a higher price as he spent time talking with me) is convinced in his 40+ years of subzero repair, that the root of the issue is related to something causing excessive air getting into the freezer compartment. This would be caused typically, he said, by 1. Door seal problem - causing air to get in, or 2. Door left open slightly. I have inspected the door seal very closely. It is not damaged or warped, deformed in any way I can see. I have cleaned them with soap/water as there was some food-stuff but nothing that just stood out as an amount of food-stuff that would defeat the purpose of a door seal. I have tested the door closing on it's own (assume you just let the door "go" when the door is in the motion of closing) - the door closes. I can hear like a vacuum sound after the door closes most times. So, I conclude two things at this point, maybe 3. 1. Something is causing the defrost cycle to intermittently not engage. I have a spare defrost timer and both work fine. 2. When excessive icing occurs, it seems to be related to icing in the very BACK of the coils that once that area is defrosted, "everything works as it should" -- as I mention in an earlier post, related to enough icing around the discriminator wiring harness expands the contacts in that harness to impeded an electrical connection (this was the theory from the expert with subzero experience). 3. So, I know how to fix, the general symptoms, but not the root cause (why is the defrost cycle missing or stated another way, why is the discriminator not engaging - which based on my data, is because of excessive icing in that area of the back of the condenser coil. Perhaps a damaged wire harness. Perhaps the discriminator part with that funky clip did not get reinstalled correctly (which I do not want to go through that again as that is a task to say the least). I think I will reinstall all of the covers this weekend and go back to my physical inspection when I am in the freezer (quick bend back the metal panel slightly, use flashlight to look at condenser coil icing. Check that door is closed, pay attention when door is opening / closing....

@Mark-ji5ve

4 ай бұрын

Darn. My journey continues. 6th day with light cover off, panel off in freezer. This AM I noticed too much ice/frosting on condenser coils. I manually moved the defrost timer with screw driver to force a manual defrost. Freezer compressor turns off (expected), but the heating coil does not engage (to touch, not getting warm). I have a spare Defrost Control (Supco - Amazon sourced) to replace a ~2 yr old OEM defrost control (yes, turned power off before doing this). Power on, manually moved this defrost control to force a defrost cycle. Same behaviour, result -- no warming of the coils. I had to go to work (upstairs in my home office). So, I decided to turn off the freezer from the dial control inside of the refrigerator and leave it. I have a couple of thermostats -- manually read and an Ecobee sensor so I could keep on eye on temp. Idea was to see if it would do some manual defrost on its on. Fast forward about 14 hours, temp in freezer was at about 32 F. The coils defrosted some for sure, still more ice that should be there, but there was less then this AM. I turned freezer back on. Manually forced a defrost cycle. Heating element engaged! So, moved the freezer temp setting to 3 (usually have it at 4 to 5 on the dial). I will keep watching -- not going to reassemble this weekend.

Yo. I have your exact refrigerator, April 95. My fridge runs all the time and the freezer evaporator ices up every couple months, needs manual OFF and defrosting. I read elsewhere that it might be the defrost timer. Could it be that your defrost timer never turned off while mine never turns off?

@PIFDIY

6 ай бұрын

If you watch my video, I troubleshoot the defrost timer. It's easy to get to and to test.

I think I have the EXACT problem. What’s the part number for the defrost timer?

Thanks for sharing! I got same issue, but it was defrost timer . Can you please share part number?

@PIFDIY

7 ай бұрын

This part worked for my 590 - www.amazon.com/gp/product/B00VS90PM0/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

@kirill3751

7 ай бұрын

@@PIFDIY Thanks! Do you need to swap the wires or is it just plugged right into the connector? It looks a little different ( color) than the original timer..

@PIFDIY

7 ай бұрын

The connector is the same as the OEM timer. Just plug it in. @@kirill3751

@jingxie4391

5 ай бұрын

Nice video. Thanks. @kirill3751 could you confirm if the timer worked for you?

@kirill3751

5 ай бұрын

@@jingxie4391 Hi, yes, it works great

UP DO NOT NEED REMOVE THE SIDE RAILS JUST LEFT UP THE PANEL AND REMOVE IT.

@PIFDIY

6 ай бұрын

Thanks! I figured this out when I reinstalled the rails...

@Mark-ji5ve

4 ай бұрын

Agree with @anthonymartin2412. I did not have to remove as much as @PIFDIY showed in video. But the hardest part, with out a doubt, is the discriminator part at the back of coil. @PIFDIY is correct in that once the coil/condenser is "dropped" off the mounts, it can only be moved so far as it is attached to the sealed cooper refrigerant lines. The spacing left over is very difficult (for anyone) to maneuver to get to the discriminator and that damn clip around the coil. I had to use muscle memory and position my self just right AND multiple tries to get the clip to secure to the condenser coil line. Still a great video on this topic.....

@tombrownca

25 күн бұрын

I wonder. Does that little heat sensor bulb part need to be tucked back in to the original holding clip location? Or once loosened free of its housing can it just float or hang wherever?