Author Topic: best method to restore conductive keypads?  (Read 13392 times)

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Offline elecdonia

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Re: best method to restore conductive keypads?
« Reply #25 on: February 27, 2023, 03:44:43 am »
I use these:
 
                 ButtonWorx Rubber Keypad Repair Kit

Sold on Amazon. Copy and paste the line above into Amazon search.

These are self-adhesive conductive pads which you stick onto the PC board. The original rubber button presses on the new self-adhesive pad. These are easy to apply. The adhesive is strong enough. Performance is excellent.

I’m learning to be a leading-edge designer of trailing-edge technology.
 

Online CatalinaWOW

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Re: best method to restore conductive keypads?
« Reply #26 on: February 27, 2023, 04:36:08 am »
There seem to be lots of slightly different but similar processes in these buttons.  In some I have found there is a large volume of conductive material on the back of the button.  The failure mode on these seems to be degradation of the surface layer (oxidation, lost of softener, who knows) and removal of the surface layer is an effective and long lasting cure.  One others the problem is too much material transferred from the button to the PC board, lowering the resistance between the traces constantly.  How high it needs to be varies depending on their readout strategy and the deposits causing the problem may be a long ways from the contact point.   

Some of these buttons allow very little travel so adding a new pad on top of the existing ones is problematic.

Another suggestion that can sometimes work is installing a carefully placed and insulated snap disk from that style of switch.  I like the idea of electrons flowing through continuous metal instead of depending on the contact between thousands of tiny particles, but the geometry on this approach is fiddly and doesn't often work.

For those putting foil or other toppers on contact cement (used to install laminate countertops) is strong and remains pliable.  I can't speak to its adhesion to the "rubber" used in these buttons, but with proper cleaning it probably works.  Surface prep is everything with any adhesive.
 

Offline Greybeard

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Re: best method to restore conductive keypads?
« Reply #27 on: February 27, 2023, 12:03:30 pm »
I used a repair kit containing thin conductible  rubber pads, that must glued on the rubber foil with CA glue. Sometimes you have to grind off (Dremel) the old rubber pad to make place for the new one. Found on AliExpress or similar source.
« Last Edit: February 27, 2023, 12:05:31 pm by Greybeard »
 

Offline artag

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Re: best method to restore conductive keypads?
« Reply #28 on: February 27, 2023, 12:22:01 pm »
I got some kits from {amazon, ebay, can't remember} - https://termopasty.pl/en/kategorie/electroconductive-materials/
Haven't tried them yet but the company looks like they're knowledgable and they come with a tube of silicone glue which should be better than CA

 

Online coppercone2Topic starter

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Re: best method to restore conductive keypads?
« Reply #29 on: March 01, 2023, 02:49:53 am »
I got and applied the keypad repair kit, It works wonderfully now.

My process was to
1) file all the keys down with a 400 grit sanding stick
2) spray wash with alcohol
3) q-tip with alcohol clean
4) paint on conductive coating with fine paintbrush
5) after 1 hour room temp cure, bake at 80C for 1 hour.

Other then being tedious to apply, and also slightly expensive, since the kit is 1 use, it seems to work great. Only time will tell I guess.
 

Offline DarkAngel

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Re: best method to restore conductive keypads?
« Reply #30 on: October 13, 2024, 09:17:47 am »
.
FAILURE IS THAT IN MANY REMOTES, OVER TIME THE CONDUCTIVE RUBBER MATERIAL UNDER THE KEYPAD BUTTON, ALWAYS TURNS INTO MIX OF CLEAR "GOOP" AND BLACK CARBON MATERIAL. One must "mash down" very hard and slide the button around with your finger to make a connection...which is unreliable. I've seen the degradation of the switch take anywhere from less than 1 year to over 10 years, depending on the brand. I have to replace my Cox remote every few years because of this repeating failure.

The "rubber" keypad failures I run into are that over time the buttons degrade in some way and create some sort of clear GOOP on the entire contact interface consisting of the conductive rubber pad and the metal "interlocked fingers" kind of pattern on a metal side of the PCB board.
I can usually clean off the "goop" and it MAY work again for some time, but this method usually also removes quite a lot of the black (assumed carbon) material that had been partially disolved and mixed into the "grown" goop, so this repair can't be performed more than a few times before there's ZERO carbon left to form any electrical connection.

Is there a repair kit for this specific type of remote's keypad button's failure?
 

Offline BILLPOD

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Re: best method to restore conductive keypads?
« Reply #31 on: October 13, 2024, 01:41:42 pm »
Good Morning DarkAngel, What works best for me, is the conductive paint.   I clean the rubber contacts and the corresponding traces on the PCB with IPA and then dab some of the paint on the rubber pads.  This paint is super fast drying and by the time I reassemble the remote it's ready to go. ^-^
 

Online TERRA Operative

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Re: best method to restore conductive keypads?
« Reply #32 on: October 13, 2024, 04:38:46 pm »
You can buy kits of conductive pads from ebay/aliexpress/etc.

https://www.ebay.com/sch/i.html?_nkw=conductive+pad+keypad+repair+kit
Where does all this test equipment keep coming from?!?

https://www.youtube.com/NearFarMedia/
 

Offline Dave Wise

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Re: best method to restore conductive keypads?
« Reply #33 on: October 15, 2024, 12:51:11 am »
My old stereo remote slowly became unusable.  Pen-applied nickel worked at first but quickly flaked off.  Then I cut little disks of brass foil and attached them to the rubber pads with contact cement.  I only did worn out pads like Mute, Volume+, Volume-, Power.  Couple months of heavy use and still fine.
 


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