How to repair KPLs that "Click, Buzz, turn on/off continuously"

[blueman2]

Edit: read to post #13 for details on the successful repair method

 

 

Out of 7 KPL's I purchased in 2011, 5 have failed with the famous clicking, buzzing, turning load on and off symptom.  With the price of these being $75 or more, I would love to be able to somehow repair these devices rather than throw them away.  I am considering taking a few apart and trying to replace capacitors, as that is the most common item to fail on electronics.  I do know that if I try long enough doing repeated 'restore' commands, I can sometimes get a few to respond and work temporarily - until power is removed and restored, at which point they go into the clicking and buzzing and cycling state.  So that leads me to believe that the eprom and digital section is still intact, leading be back to the capacitor idea.

 

So, has anyone else tried this?  Any pointers?  Otherwise, I will just start replacing caps and see what happens.     

[Teken]

Out of 7 KPL's I purchased in 2011, 5 have failed with the famous clicking, buzzing, turning load on and off symptom.  With the price of these being $75 or more, I would love to be able to somehow repair these devices rather than throw them away.  I am considering taking a few apart and trying to replace capacitors, as that is the most common item to fail on electronics.  I do know that if I try long enough doing repeated 'restore' commands, I can sometimes get a few to respond and work temporarily - until power is removed and restored, at which point they go into the clicking and buzzing and cycling state.  So that leads me to believe that the eprom and digital section is still intact, leading be back to the capacitor idea.

 

So, has anyone else tried this?  Any pointers?  Otherwise, I will just start replacing caps and see what happens.     

 

To be clear, five of them have failed since the initial purchase in 2011. Or that five KPL's have failed just recently in 2014?

[blueman2]

5 have failed in 3 year period.  About 2 per year.   Each time, it has been either after a brown/blackout or after I have restored power to a circuit after working on it.  So I am guessing there is some sort of power spike causing these failures.  

 

BTW, I have disassembled one KPL already.  It is a rather complicated process to take one apart, including the need to drill out a rivet holding the triac power controller to the case (it is riveted there to allow heat transfer). 

 

The main board has 5 caps, one main power resistor and what appears to be a small reed type switch which is probably the source of the clicking sound we hear when these fail.  I will let you know as I learn more.  

[Teken]

5 have failed in 3 year period.  About 2 per year.   Each time, it has been either after a brown/blackout or after I have restored power to a circuit after working on it.  So I am guessing there is some sort of power spike causing these failures.  

 

Yes, this is what I gathered you were going to say.

 

Its safe to say the earlier designs were not built to be very robust when dealing with electrical surge events. Note a voltage (sag) is actually more harmful to a electronic device as when the voltage goes low, current increases.

 

This increase in current will quickly burn out any sensitive IC's or thin wiring traces etc. Note, as a best practice if I am going to turn off the breaker and there is a large load on the same circuit being restored. I always pull out the air gap first, turn on the breaker, then reset the gap button.

 

I did this to all the old KPL's in the home to ensure nothing would burn up. The newer KPL's appear to be more tolerant with surge / spike issues. I can't say how they operate or would function during a voltage sag event. As it would require a regulated power supply to keep the voltage stable and not impact the device.

 

I am unsure if such a design consideration is in place for Insteon devices to be honest. 

[blueman2]

Here is the main board.  No obviously blown caps, but the 3rd component from the left (back row) shows some corrosion.  It is a 1mH inductor (not a cap, though it looks just like one).  Also, the long silver component on the left, just to the left of the green ferrite ring where the red load wire exits the board, appears to have overheated.    

 

On the right front edge of the board, you can see the triac that was riveted to the side of the aluminum case.   

 

 

[Xathros]

That long silver one looks to me like a Quartz Crystal.  Is there a component label near it on the board?

 

-Xathros

[Brian H]

The silver cylinder glued to the PCB looks like a crystal for the processors oscillator.

[blueman2]

Cannot make out the markings on the silver object, but yes, it is connected directly to the largest IC so probably is a crystal.  Good call.  Odd that it appears to have been rather hot based on some of the scorching of the glue holding it down.  

[arw01]

Be interested in what you find here, I fried a dual band by wiring the load wrong, then fried another one doing the same thing before I figured out what i was doing because I was not at the device when I flipped the breaker to see that it was frying  

 

Have not taken mine part but the triac is toast..

[blueman2]

Here is a detail on the crystal after I scraped the burned glue off of it.   Yes, definitely a crystal at 5.5296 mHz.  I did check the 2 inductors, and they both tested OK at 2.5 ohms.  Large capacitor seemed to test OK, but hard to be sure without removing it.  I do not have the equipment to check the crystal, unfortunately.  

 

 

 

[Brian H]

I would suspect the electrolytic capacitors. In the 2413S PLM. The caps where bad but showed no signs of bulging or spilling out their guts. I don't have a capacitor or RSR meter to test them.

 

The green one second from the left is one of the brands in the PLMs. I can't read the brand of the other ones.

[blueman2]

I would suspect the electrolytic capacitors. In the 2413S PLM. The caps where bad but showed no signs of bulging or spilling out their guts. I don't have a capacitor or RSR meter to test them.

 

The green one second from the left is one of the brands in the PLMs. I can't read the brand of the other ones.

 

Well, well.  I did end up doing a basic test of all the caps without removing them.  I used my trusty Fluke on resistance setting to charge them up, then used voltage setting to see if I got any residual voltage from them.  All gave residual voltage except the green one.  

 

I think I will remove it and see if I can find a spare somewhere in my workshop. Otherwise, off to Radio Shack.   

 

Different view of caps it that helps.

 

[blueman2]

Brian H and Teken, you da' MAN, er, MEN!!!  It was the green capacitor!!!!!  

 

I did not have an exact replacement (it is a 10uF 16V), but I did have a 22uF 35V capacitor laying around and replaced the green one.  Put it back together and BINGO!!!!  It works!!!  

 

Now, even better news.  I did the repair on another switch WITHOUT taking the entire switch apart.  Taking it totally apart (removing the circuit board to get to the bottom side) is a problem because you have to drill out the TRIAC and putting that back on is a pain.  So it would be best to not have to access the back (solder) side of the board.   Here is the procedure:

 

1. Remove the 4 screws that hold the clear plastic jacket on.  They are on the 4 corners on the front of the switch.
2. Remove the clear plastic jacket.  Pull the White,Black,Red wires out or give enough slack to access the green capacitor.  If you can, avoid breaking the small red and black wires to the piezo speaker that is glued to the inside of the clear plastic shell.  I just cut my speaker wires off since I do not care about the sound.    
3. Find the 10uF 16V green capacitor using the picture in post #12 above.  It might not be green.  But it should be the only 16V 10uF cap.  It should also be labled C8 on the circuit board.  Note and write down which side is + and -.  There should be a + on the circuit board, but if not, WRITE IT DOWN so you know polarity.  To remove the capacitor, just rock the green capacitor back and forth until you eventually stress the wires so much they break.  Do it gently at first and it will take anywhere from 10 to 50 pushes back and forth to finally break off the leads. You might also want to try a clockwise-counterclockwise twisting motion back and forth to break the leads.
4. If one of the leads is sticking out from the pad, cut it off level as you can with the circuit board.  Now, use your soldering iron to put a bead of solder on each pad where the capacitor was.  
5. Cut the leads on the new capacitor to be short (about 1/4 inch) and place a small bead of solder on the tip of each wire on the cap. Then place the capacitor at an angle so that you can solder it on.  MAKE SURE TO OBSERVE POLARITY.  I forgot to take a picture while my switch was apart, but here is one from the outside of the switch. 

 

So guys, we now have a method to fix all of those broken KPLs!!!!!   Brian H recommends using Low ESR capacitor with 105 degree rating.  These should last longer.  Lots of them on eBay.  Don't worry about the voltage rating, so long as it is above 16V.  50V will work just fine, for example.  

 

[Brian H]

Your photos didn't show the power supply IC.

The LNK354 switching power supply IC was used in many of the Insteon modules. Including the 2413S/U PLM.

If your module used that IC. The capacitors you use should be of a Low ESR type. If not they will fail in a much shorter time than a low ESR one will.

[blueman2]

Brian H, 

 

I will take apart one of the KPLs and take a picture of all the chips.  Dumb of me not to do that before.  In any case, I guess I can go with low ESR caps by default, since there is not downside (that I know of) other than higher cost.  But then, this is the first time I have ever been made aware of low ESR quality criteria for capacitors.  It has been decades since my EE classes, but a quick wiki read on the subject brings it all back.  I want it to go away again

[Teken]

Note, this repair only addresses the case where the failure point is the capacitor. It won't help anyone if its any of the IC's or surface mounted resistors which are almost impossible to see the values.

 

Regardless, great write up and follow up.

[blueman2]

Good point, Teken.  I do see a lot of posts in forums related to Insteon where people have 2011 era KPLs that have failed with buzzing, clicking and load turning on/off symptoms.  All 5 of my failures are of this type.  And all 5 were fixed with this capacitor replacement.  So at least we appear to have a fix for this one failure mode. 

 

If, however, the KPL was damaged due to shorted load which might kills the triac (see arw01's post above) then this will not help.  Worst case, if you are having these symptoms, give the cap replacement a try.  Cheap and relatively easy if you have soldering skills.  

 

Thanks again for the help and support in getting this fixed.  Especially to Brian, for the lead on the green capacitor.  

[Teken]

Good point, Teken.  I do see a lot of posts in forums related to Insteon where people have 2011 era KPLs that have failed with buzzing, clicking and load turning on/off symptoms.  All 5 of my failures are of this type.  And all 5 were fixed with this capacitor replacement.  So at least we appear to have a fix for this one failure mode. 

 

If, however, the KPL was damaged due to shorted load which might kills the triac (see arw01's post above) then this will not help.  Worst case, if you are having these symptoms, give the cap replacement a try.  Cheap and relatively easy if you have soldering skills.  

 

Thanks again for the help and support in getting this fixed.  Especially to Brian, for the lead on the green capacitor.  

 

I believe the forum has to thank you for taking the time to document and trial this fix. I have surely kept this thread as one of my favorites for future use and possible fix's for others in the same boat.

 

Once again, awesome write up and Merry XMAS!

[Brian H]

If the KPL has a sounder in it. Maybe the flaky power supply was making it pulse and click.

[blueman2]

If the KPL has a sounder in it. Maybe the flaky power supply was making it pulse and click.

 

Duh!!!  I bet you are right.  It seemed odd to me for a non-relay dimmer to make any clicking noise.  It HAD to be coming from the piezo speaker.  Good catch.  

[Xathros]

I have one KPLD that failed in this way.  Does anyone have a Mouser or Digikey PN for the preferred Low ESR cap to replace with?

 

-Xathros

[blueman2]

I would just go to eBay and search for 10uf low esr capacitor.  Most will be 50V or more, but voltage does not matter as long as it is higher than you need.  You should be able to get 5 for $4 or less.  I know you only need 1, but it will probably be cheaper than Mouser or Digikey.

 

Here is a good USA source of quality caps:

 

http://www.ebay.com/itm/5x-Panasonic-FC-Low-ESR-10uf-50V-105C-5x11-mm-USA-seller-/221617353683?pt=LH_DefaultDomain_0&hash=item33996c73d3

[Xathros]

Thank you.  Order placed.

 

-Xathros

[arw01]

+1 on the thank you, just lost another older used KPL to the same buzzy clicky flashy.  Had to shut down power to do some 220 volt wiring and when I came back up it was done for.  I may do a couple more factory resets on it to see if I can get it up for a week while the caps come.  Have one in the house to do to at the front door and another used one in the stash box, so will do all three of them.

 

Alan

[Brian H]

Sounds like the capacitor was poorly filtering the power supply and when you had to start back up. The supply never was able to get enough filtering on a cold start. For a high enough or smooth enough voltage source.