Friday, March 18, 2016

Here is a big diversion...Undercounter Ice Maker Repair. Kenmore Elite 106.89583705

I follow a few really smart folks who do a great job at describing how they troubleshoot, and then repair.  his YouTube channel.

The Signal Path Blog

Those are the two I reference most...but there are another handful of folks that do a great job of documenting a problem, their investigation, and the solution...or sometimes no solution.

Because of those inputs I have repaired a handful of wall-wart power supplies, 3 monitors, 5 computers...and now an Undercounter Ice Maker. (similar to the pic below)

I know...what the heck does an ice maker have to do with Electronics?   ...just wait.

SO the house we bought a couple of years ago came with a few extras...including a Kenmore Elite Undercounter Ice Maker  Model 106.89583705 manufactured in 2011.11.

First, let me tell you that after decades of using funny smelling refrigerator ice...a stand alone ice maker makes terrific smelling and tasting I wouldn't have thought of buying one myself, but now after using one, I cannot go back to fridge ice.

Quick background.  Fairly simple device.  Main ice storage area maintains a cool temp, a water tray within this area is filled with water.  A plate is cooled until frost forms on it, water from the water tray is gently poured over the cooled plate until ice of a certain thickness is a certain point the cooled tray is warmed, the ice slides off and onto a grid of warm wires...the wires slowly cut through the ice (combination of gravity and slight heat)..the ice falls into the main bin...and the cycle starts over.

So there are some main parts...the refrigeration unit...cools the main box, and the plate.   The water tray that need to be filled to a certain level.  The pump that pushes the water gently over the cooled plate.  The pump that empties the excess water from the water tray. and the grid that cuts the ice...and of course a way to measure temps.

When we first moved in, the ice maker was making a ridiculous amount of open the door and ice falls out.   After a tiny bit of research I learned the temp probe in the main box was bad...easy plug and play fix.

After about  a year of living there, the unit stopped making ice...sometime in February (We live in the south, ice is a thing year round).   After a lot of time googling, I found a couple of service manuals (for older models) and a bunch of forum questions, and few answers.

The service manual I used... a KitchenAid 2007 15" and 18" Automatic Ice Maker pdf, KAR-19.

This web page describes how do do the self test.

Guess what...all the machines are identical.   I actually used whirlpool replacement parts.  (I have a Kenmore machine)

Ok,on  to the repair.

I pulled some of the internal panels off to get a better view of the machine, and what it was doing...the first thing I noticed was the water level sensor middle wire was hanging loose...I am not a refrigeration engineer...but I think that is a possible problem.

I assume the plugs are standard I search Digikey and find a plug that looks similar, and has similar I buy a male and female and 6 of the male and female pins (I figured I would have problems...I was right)

 I also had to get a crimper for those pins...I had one for smaller servo pins...but not this size.

Long story short...I  had to pull the unit out from the cabinet, remove an access panel on the back, unplug a molex connector, and shove the wireing harness through into the box to get enough access to fix the other end.  (the water sensor was removeable, but the matching harness was in the back of the unit.

When I first investigated I saw the middle pin on the water sensor was corroded and out...I assumed the other end of the connector was just as bad...I was right.

So all that is fixed, put it partially back together, do a test...and still it won't circulate water over the cooling it still won't make ice...ok, so maybe the "recirculation pump" is also defective.

They do go bad, so I bought a replacement recirculation pump...and a replacement water sensor while I was at it (my fix didn't test correctly).

Again, partially back together, do a test, and still won't circulate the water over the plate.

The only thing left to replace is the $270 control board...

Looking at some pictures of the control board, I see that mostly it is relays...I follow the schematic from the service manual...and all the wires correctly end at the control board.   (my Kenmore icemaker has Whirlpool #2304129 rev b)

My control board is identical to that reference picture except for the relay make and model.  For reference, the first pin on the right of the big black 6-pin socket is pin #6...that pin runs the recirculating pump. The next pin over (#5) is power, and the pin left of that (#4) runs the water tray drain pump.   The broken relay is the third one over from the right of the two under the sticker. (the other one under the sticker is for the drain pump).  I think the two at the right side are for the heating grid and the lamp...the big relay below the two with the sticker I think is for the A/C system.

I figure I have nothing to lose by replacing a relay on that control board

I look at a close up of a replacement board and get relay OMRON G5LE-1R4DC9

I pull my board after the replacements arrive (I got spares) and see this model.

Digikey shows this as a discontinued part, but the specs were almost identical to the OMRON that comes on the replacement board.

There is a conformal coating on the PCB, but a bit of heat gun and some scraping removed it...also before I desoldered the old relay, I added some solder to the pins.

I had a 9vdc power supply to test the relays...I used the continuity 'tone' on the multimeter with the probes clipped to the switch pins...when I applied power to the new relay I heard the successful then I tested the one I desoldered...if it failed the test, then that means my guess was fingers crossed that it would fail...the relay did click, but the contact did not close...whew!

The fix was successful!  I put some silicone sealer over the resoldered pins...and reassembled the machine...after about 30 minutes to cool down, it started to make ice again.

Grand total.

I had to fix the pins...a few bucks for parts, and $12 for the crimper
I replaced the pump, but didn't need to (so now I have a spare)  $60
I couldn't successfully fix the pins on the water sensor so I replaced it  $30.

and to fix the control board... a $1.50 relay.

I posted all this, because I used to think that things like this (the control board) were not repairable...but the reality is, many parts are replaceable if you do some research and have the tools...

For me, the single most important tool I have acquired over the last few years is my desoldering unit.