Whirlpool Refrigerator LED lights flickering

[Dave125]

Re: Whirlpool Refrigerator LED lights flickering

Bluto -

I'm facing the exact same problem on a Kenmore fridge; apparently many domestic fridges used the same set of three Whirlpool LED PCBAs.

However, on my control board, R15 (LED side of the board) is obviously toasted. Since your R15 appears to re unaffected, could you tell me the value marked on your R15?

The adjacent R17 is unaffected, and is marked 910 ohms. I've done a lot of research on this problem, and others have reported both R15 and R17 as having been grossly overheated, enough to obliterate the markings. I have not been able to locate a schematic.

I'll take some photomicrographs of the toasted R15 on Monday, and post them here.

did replacing R15 fix the problem?

[bluto]

Re: Whirlpool Refrigerator LED lights flickering

Since your R15 appears to re unaffected, could you tell me the value marked on your R15?

My R15 reads just under 138 ohms. It looks like the number is starting to blacken, I think the code number is 1370 which would be 137 ohm +/-1%

[sam_sam_sam]

Re: Whirlpool Refrigerator LED lights flickering

If you replace LEDs modules

I would recommend that you look at the specifications of the type LED that you will be using

and make sure that they are not being over driven by too much current and voltage you will need to know how these LEDs are wired this is going to be very important to know

[Kenmore]

Re: Whirlpool Refrigerator LED lights flickering

Bluto -

I'm facing the exact same problem on a Kenmore fridge; apparently many domestic fridges used the same set of three Whirlpool LED PCBAs.

However, on my control board, R15 (LED side of the board) is obviously toasted. Since your R15 appears to re unaffected, could you tell me the value marked on your R15?

The adjacent R17 is unaffected, and is marked 910 ohms. I've done a lot of research on this problem, and others have reported both R15 and R17 as having been grossly overheated, enough to obliterate the markings. I have not been able to locate a schematic.

I'll take some photomicrographs of the toasted R15 on Monday, and post them here.

[redwire]

Re: Whirlpool Refrigerator LED lights flickering

I kinda thought an LED is to blame, see all four have the "black dot of death" in pics?

Maybe the primary cap failed and then it hiccuped and killed the LEDs. It's not like they run for very long or get hot (in a fridge), unless Whirlpool overdrives them.
It looks like the PCB uses SMD 5630 LED's with 4-pin package and thermal pad, around 1/2W ea. Also has footprints to take SMD 5050 6-pin LED with thermal pad. I'd order a bunch of new LEDs.

All that electronics to light up four LEDs with fade effect. 38 testpoints

[stj]

Re: Whirlpool Refrigerator LED lights flickering

are the led's in series though??

[bluto]

Re: Whirlpool Refrigerator LED lights flickering

Oh noes, the flickering is back today! Arrgh... I don't know what to do next.

Maybe isolate the fade in bit and just tie the gate voltage of that transistor to Vcc? I might have to buy another one so I can experiment on the original.

This thing really shouldn't fail en-mass like what I have seen online as described above.

@stj, I don't think it is a bad LED because all 4 along with the other two LED modules connected to the output port are all acting up at the same time (intermittently).

[stj]

Re: Whirlpool Refrigerator LED lights flickering

it's probably a bad led, i see the board is designed to take 2 different styles.

[bluto]

I have a Whirlpool side by side fridge that is not even 2.5 years old. Recently the LED lights inside the fridge and freezer started acting up. Instead of fading on when the door was opened, the lights would just flicker slightly. Closing the door and re-opening would seemingly fix the problem. The problem was intermittent, but I figured it was only going to get worse so I decided to do something about it.

After some Internet searches, I determined that I was not the only with with this problem. There were dozens of reports of the problems with the same light module as what is in my fridge (W10515058). There were people that said they light failed when the fridge was just 19 months old. Some folks said they replaced the flickering module (spending between $75-$150) and it failed again in a year or two. There were some helpful videos on removing the module that also had some dubious fix suggestions.

To start with, I removed the module following the instructions in this video: https://www.youtube.com/watch?v=pCY2iaOFgN8

The module has two connectors. The first provides 120v to the board to power the lights when either the fridge or freezer door is opened. The second connector provides DC power to the other lights in the bottom of the fridge and freezer. Once this module is removed, all lights in the fridge will not function.



Upon examining the module, the first thing that strikes me is how well it is made. It is a multi layer board with mainly SMD components. It also has a conformal coating over the board and all components. There is no fancy control logic chip, so I would surmise that the the fade-in effect is orchestrated by a simple resistor-capacitor timing circuit. And this board operates in a nice, constantly chilly environment for 15 to 20 seconds at a time... So what excuse does it have for not lasting 10+ years?

I am going to take a stab at this and say that the problem is with one of the electrolytic capacitors on the board. There are a total of three of these capacitors present, a 3.3uf 400v (C6) and 2x 100uf 50v (C7 + C8). The first one appears to be the primary side filtering capacitor as it is near the 120v connector and in between the 4 diodes that seem to be the rectifier. The issue that I see is that the brand of this capacitor is 'Lelon' which happens to be on our bad capacitor list here. The other two caps are 'Nichicon' which are on our good list.

EDIT: Replacing C6 did not solve the problem! I am still working to find a permanent fix and will update the thread when a solution is found.

EDIT: September 2021:

port443 seems to have found the solution to fix these boards:

Confirmed and solved.

My board had burnt-looking R15 with board lacquer damaged on top of it.
Board needs 320+ degrees Celsius of iron temperature to melt the lacquer.

Soldered 150 Ohm 1/2 W huge resistor in place of that bugger: there's a lot of space available around.

Looking at all discussion, it looks like a design mistake: the wattage of resistor was not calculated right.

slim_jim also fixed his light and noted:

I repaired mine this way also. My original R15 chip resistor was scorched but not blown. One end had broken free. The old resistor checked 135 ohms.

The light fade-on effect is absent, possibly because I used a 150 ohm resistor instead of 135.

Thanks port443.