Restoring Faulty Silicone Membrane Buttons on TV Remotes

[jonovid]

seeking a second opinion on why the
loss of conductivity of remote controller membrane buttons.
almost every TV or set top box or game remote controller has buttons that stop reacting after a while,
and I or others end up squeezing the remote out of his life while trying to switch or use it.

buttons on those silicone membranes have little black rubber disks or peg on the back that actually make the button-contact
to the pcb. this is some-how losing its conductivity.
 youtube describes many different ways to fix remote controller buttons.
from the use aluminum foil , sandpaper , to solvents like acetone cleaner.
the replacement of the little black disks or pegs in the silicone button membrane.
I do not want to damage the little black rubber disks or pegs or even the pcb tracks.
what is the best way of restoring them to as-new reliability in switching conductivity?
as most solvents do not work 100% of the time. or may do more damage.

[tunk]

I don't know if you've seen this (haven't tried it myself though):

[Buriedcode]

The two methods I've used are:

- Find an old remote, and carefully, with a scalpel, remove the small conductive rubber discs on the bottom of a membrane as a replacement.  Glued in place with B-7000.

- Bought replacement conductive rubber discs in various sizes - from about 1.5 - 4mm diameter, form Ebay for about £3 for 100.

Both work rather well.

[BravoV]

Although I dont know how long it will last, I rubbed gently the pad with a really soft pencil, maybe BBB softer lead (I forgot)  , and it worked at that time. Now the device and the remote alreaady long gone, so I dont know if its still working.

[splin]

Funnily enough I was just about to ask the same question. I've never had any luck cleaning then with isopropyl alcohol; perhaps the HFE contact cleaner he used in that video is more effective.

- Bought replacement conductive rubber discs in various sizes - from about 1.5 - 4mm diameter, form Ebay for about £3 for 100.

Thank you! I found these to be the cheapest at £4.99 for 450 assorted pieces:

https://www.ebay.co.uk/itm/450pcs-2mm-8mm-Conductive-Pads-Keypad-Repair-Kits-For-IR-Remote-Controller/264384351335?hash=item3d8e890c67:g:WaYAAOSwGIJdGwO0

Alll the ones on Aliexpress were quite a bit more expensive because of relatively high shipping costs.

[EDIT] All the 100 piece kits (10 off of 10 sizes) I could find on Ebay were as, or even more, expensive than the above. In any case odds are that you only ever need one size and you end up using all 10 of them on one remote and the rest never get used - just like all those cheap packs of alkaline button cells where you only ever use the AG13 size - after which you end up trying to use cardboard shims, and/or bending contacts, to fit the thinner ones! And who hasn't got a load of CR2016s that they'll never use? 

[PlainName]

My Proline TV remote where I only ever press the power button got bad enough that I determined to fix it properly (I'd already had it apart and cleaned the contacts). To that end I purchased a bag of the little black dot replacement tips, but before I got around to using them I found a brand new remote on Ebay for less than postage cost, which I couldn't resist. Works fine

But wait! That's not my fix. I could have just used this new remote instead, but eventually the issue would crop up again. Hopefully, by that time I would have gotten around to fixing the original with the black dots. However, in the period where it had started going bad I'd set up a one-for-all type remote (actually a RiiMote 2.4GHz keyboard with IR capability). That works a lot better and the power button seems to be much better quality and likely to last forever, so I figured I could keep the new remote in its box for emergencies and carry on using the RiiMote.

Probably not a fix suitable for everyone and somewhat against the grain of the topic, but it works for me 

[madires]

Can be fixed easily with graphite lacquer and a small paint brush.

[RoGeorge]

Brush them with water and soap, both the rubber and the PCB.

[BravoV]

Even though I've suggested to use pencil as it was long time ago, on few cases in the past I used this (attached below), it just works.

[Ian.M]

As long as the silicone button mat isn't torn or split and the contacts on the PCB are in good condition, I've usually had good results from simply cleaning the contacts.

My usual procedure is first to clean the PCB with a low residue contact cleaner.  Its advisable to be very cautious if it has carbon contacts on the PCB as some solvents will soften the carbon ink and make it far too easy to accidentally wipe off, so test whatever you use with a fresh Q tip lightly moistened with the solvent gently on one carbon track, (preferably where its used as a bridge that could be replaced with a soldered fine magnet wire jumper rather than an actual contact pad) to see if any carbon transfers to the Q tip.  I also examine the board for obvious defects like cracked solder joints and repair any I see at this stage.

Next I wash the mat with hot water + a little dish detergent to remove gross oily contamination from handling and plasticiser migration, rinse it thoroughly, then dry it. Depending on condition I may also wash the plastic upper shell. If the remote is in particularly clean condition, with no signs of contamination, I may skip the whole washing step.

To clean the carbon loaded contact pads, I use cartridge paper (or heavy copier paper).  Put the paper on a flat hard surface, and push each button in turn down so its contact pad is flat on the paper while pulling the whole mat sideways for an inch or two.  You are doing it right when the contact pad leaves a dark streak on the paper.   

After all the contact pads on the mat have all been cleaned once, partially reassemble the remote enough to test it, and note if any buttons are making poor contact to investigate further.  Check the board contacts with a known good button pad pressed down at the faulty position to see if the bad button is due to a bad pad or a problem with the board e.g. a loss of contact at a via or cracked carbon at the edge of the copper track.  Printed carbon contact board faults are often fixable by lightly abrading the track and contact then bridging the break with silver conductive ink, which *MUST* be allowed to fully cure.

If its the contact pad that's at fault, inspect it for damage and if none is visible, clean it again on the paper, pressing harder and pulling it further to expose a fresh surface layer with hopefully restored conductivity.  Gluing on any sort of replacement contact is a last resort due to the difficulty of getting good adhesion to the silicone mat.

[Emo]

Hi,

A conductive rubber compound is sold specifically for this purpose. I did successful repairs that still hold after 2 years.
It is still available on eBay

Eric

[NiHaoMike]

What about solder in a SMD snap button if you can find one that fits? Actually, some TV remotes do use snap buttons for the "higher quality" feel.

I wonder if the problems with TV remotes have a lot to do with the users eating oily snacks while watching TV, since cheap PC keyboards are similar but rarely have problems even with lots of use.

[Buriedcode]

Remotes can get awfully dirty.  Grease, dust, dirt, spillages all stay there, and carefully cleaning the board first with soapy water then IPA will do.  I say carefully because the carbon fingers are quite delicate, and even kitchen/paper towel is abrasive enough to take off a fair amount of material with normal usage.

Sometimes the conductive rubber is at fault, and I'm not sure why.  On the remotes I've cleaned/fixed, a few buttons had resistances of >50k, where-as the surrounding buttons were <2k (often 200-500ohm), these were the ones I replaced.  That does seem to happen more often on the cheaper units, so perhaps the conductive rubber layer is much thinner in the mold 

[james_s]

I've repaired many dozens of remotes over the years and I've *never* encountered one that wasn't fixed by a thorough cleaning. Take it apart, wash the board and the membrane with a bit of liquid dish soap and hot tap water. Rinse thoroughly, allow it to dry and then reassemble.

Works every time, no potions, adhesives or coatings required. The thing that happens with these is silicone oil leaches out of the rubber and coats the conductive pads and PCB. Wash that off and it's as good as new.

[rdl]

I've fixed them with a pencil in the past, but I always used the eraser end.

[madires]

I've repaired many dozens of remotes over the years and I've *never* encountered one that wasn't fixed by a thorough cleaning.

Yep, cleaning will fix the remote control in most cases. But sometimes (1 in 20?) a few buttons still don't work after cleaning. And when you check them with a DMM you get very high resistance readings or none at all. Then you need a conductive coating to fix the bad buttons.

[ususos]

Many of the tips above are good, but many components now have steel leads. As I have learned from Sally inundating my workshop, they rust when wet and look ok around the solder joint but are not. Take home is if you use water do bake in 125 F oven to dry things  out (the pc board not the membrane. I locate bad buttons by using cell phone cam to show IR blast, simple go no go. If bad, clean using yor choice of h20 soap or 90% isopropyl. Dry. rub carbon button gently with pencil eraser. apply tiny drop of DeoxIT. Has never failed. No Deoxit ? RailZip2 from hobby shop almost as good.

[james_s]

I have never seen component leads rust from simply washing them in clean water and allowing them to air dry. Are there parts that have plain steel leads that are not plated in anything? How are they soldered?

[jchw4]

I use IPA to clean PCB contacts and wash rubber buttons with warm soapy water.
You usually need a brush for the front side (button sides get very dirty) and just move your soapy hand one or twice over the pads. Don't touch pads with the brush and you will be good.

Dish washing liquid is better because it is designed to be completely washed off. Regular soap has some chemicals that soften your skin and do not want to come off.

Had 100% success with a dozen or so remotes.

The same is true for all keypads of the same type. Including front panels for the bench top tools 

PS: You usually want to wash your keypad annually, because it gets worse when dirty. Just set up a reminder to disassemble your mouse + remotes on January 1st and you will never have any issues with those 

[andy2000]

There are two methods for manufacturing these rubber keypads.  Some used conductive rubber pads, but some just have a coating of conductive paint.  The solid rubber pads respond well to cleaning, but you have to be very careful with the painted pads.  Aggressive cleaning just removes more of the paint, making it worse.  It's a good idea to identify which type you're dealing with before doing anything to it. 

The problem is that nothing seems to stick permanently to the silicone rubber they use.  Not even the paint they used at the factory lasts long under heavy use.  This is made worse if the rubber has absorbed oil from your skin. 

[james_s]

I'll keep that in mind, I guess I've been lucky in that all the remotes I've tried to fix have been the impregnated conductive rubber type.

Silicone is incredibly inert stuff and not much sticks to it. Works well for things like non-stick mats to solder on or that lay in the bottom of an oven to catch food drips. Works less well when you WANT something to stick to it. Products containing silicone oil cause a big challenge when you want to repaint something, I've seen it with pinball playfields where some kind of silicone containing wax or polish got used and then you can't touch up the paint and it's almost impossible to get the silicone out of the wood.

[TerraHertz]

My experience with remotes:
Ones I use never seem to fail. But the ones my (since deceased) wife used, would always quite quickly fail.
Eventually I realized the cause - she would frequently rub oily creams into her hands. And also eat oily finger foods like chips, while handling the remotes. It seems the silicone rubber of the key membrane sheets is permeable to oils, which diffuse through the plain silicone and get into the conductive silicone pads on the inside. With oils soaking into these, they seem to become non-conductive.

A solution I found, was to soak the entire keyboard membrane sheet in solvents for a day or two, to pull out the oils. I didn't make any notes of which solvents I tried, and it's a while ago now. I think at least IPA and metho. It does work. Also of course the PCB had to be cleaned at the same time.

Then she'd handle them with oily fingers some more, and they'd eventually die again. After multiple cycles of this, I tried wrapping the remote controls in glad-wrap, at least two layers. Then they didn't seem to fail.

[james_s]

For removing oils, I haven't found anything that works better than some stuff called Oil Eater, although Simple Green does a decent job as well. Both of those products suck the oil right out of my hands if I don't wear gloves.