IR Remote Control Wearout ?

[MrAl]

Hello there,

Anyone here know what happens to a remove such that some of the buttons dont work as well as when new? This happens with a lot of different remotes.
On inspection of the guts, there is nothing visibly wrong such as worn contacts, oxidized contacts, etc. Buttons top and bottom still look like new.

 

[atferrari]

The little I've seen was mostly corroded traces in ill ttreated controls (yes, maybe too many years ago).

 

[dr pepper]

Take out the rubber key mat chuck it in the sink and scrub it, then clean the contacts on the pcb with contact cleaner and try again.
I used to do this when I repaired consumer electronics.

 

[Nigel Goodwin]

Yes clean it as suggested, but what also happens is that the conductive rubber coating on the keypad wears off, you can buy little bottles of conductive rubber to repair it (but they are quite pricey).

 

[KeepItSimpleStupid]

A good keypad would be a conductive elastomer and a gold contact surface, so the conductive elastomer is homogeneous. A "bad" remote, might have a coating.

Check the key against a "short" and check the resistance of the elastomer.

 

[MrAl]

Hi again,

Thanks to all of you for the ideas. I'll try cleaning it first then redoing the contacts maybe if i can find something good to use for that.
Lasted about 3 years until this started happening recently.

 

[KeepItSimpleStupid]

MrAL:

**broken link removed**

 

[DerStrom8]

This happens to me all the time. Sometimes you get a bit of grime over the contacts in the remote so that the conductive rubber on the underside of the buttons doesn't connect the traces of the switch. If it's just grime, cleaning the rubber keypad with some isopropyl alcohol should do the trick. However, as mentioned, if the rubber itself wears out, you can either buy some conductive paint (which will wear off eventually as well) or just get a universal remote (I have used a bunch of these in the past).

Regards,
Matt

 

[House0Fwax]

A cheaper alternative to the conductive paint, is using contact adhesive to glue small pieces of foil to the worn out part of the rubber buttons.

 

[DerStrom8]

A cheaper alternative to the conductive paint, is using contact adhesive to glue small pieces of foil to the worn out part of the rubber buttons.

I would be concerned that the foil would wear out far more quickly than conductive paint or rubber though.

 

[flat5]

https://www.instructables.com/id/Make-Conductive-Glue-and-Glue-a-Circuit/?ALLSTEPS

 

[DerStrom8]

https://www.instructables.com/id/Make-Conductive-Glue-and-Glue-a-Circuit/?ALLSTEPS

Hmm, the resistance concerns me. It may be too high for some IR remotes. Depends on how the circuit checks the switches I suppose.

 

[flat5]

32 ohms might not be too bad. I would think the designers of a remote would not make the resistance be really low.
They know it will rise in time.
I posted the link also because it's interesting. It might be something to keep in the back of your mind.

 

[DerStrom8]

32 ohms might not be too bad. I would think the designers of a remote would not make the resistance be really low.
They know it will rise in time.
I posted the link also because it's interesting. It might be something to keep in the back of your mind.

Fair enough. I'd be curious to see if it would work on a remote.

 

[Nigel Goodwin]

Fair enough. I'd be curious to see if it would work on a remote.

Should be absolutely fine - 32 ohms is more than close enough to a S/C than you're likely to need. Bear in mind the pull-ups used are likely to be in the 100's of kilo-ohms.

 

[DerStrom8]

Should be absolutely fine - 32 ohms is more than close enough to a S/C than you're likely to need. Bear in mind the pull-ups used are likely to be in the 100's of kilo-ohms.

I'm sure you're right. It also occurred to me, however, that you're not going to have a huge glob of the conductive glue on each contact. It will only be a thin coating, which I expect would mean a higher resistance, so it would entirely depend on the pull-ups.

 

[KeepItSimpleStupid]

I basically used an opto FET at one time to bridge a scanned button (200 ohms min). The whole point for remotes is very low power consumption, so if there are pull-ups they will be huge in resistance compared to 32 ohms.

 

[MrAl]

Hi,

Some interesting ideas again. I like the looks of that conductive stuff.

I tried cleaning with alcohol and the results were mixed. Some buttons work better and some that worked before dont work as good now. Very strange.
Also, i can see the circuit board pattern in the little rubber pad on some of the buttons, which means it made a small indent in the rubber where it makes contact with the board pattern below.

I have used the aluminum foil idea in the past and i can say it works for a while but then has to be repeated. Im not sure why it stops working after a while.

I guess what i could do is try shifting the pad temporarily so different button rubbers hit different trace pads, and see if the more unused rubber button bottoms make the hard to work buttons work again. That would tell me it is definitely the rubber wearing out, because an identical button that is hardly used should be able to get the problem button position to work again. So using say the Channel Down button rubber on the Volume Down trace should get the Volume Down function to work well again. Only problem is it is hard to hold the button membrane in an unusual position with the remote apart. I'll have to see what happens i guess.

Yes i would think 32 ohms would be fine.

 

[KeepItSimpleStupid]

Semiconductor grade methanol left an electrically film on glass. We used acetone, methanol and a dip in trichlorofloroethane (Freon TF) and immedialy blown off with filtered grade 5 nitrogen or Argon.

Freon TF got banned and I'm not sure what replaced it.

The technology of our dryer had to be changed from Freon TF too.

It was two utrasonic tanks with, one with a degreaser, one with a rinse with a weir of water, so the surface was fresh and then into a Freon TF dryer. The vapors continuously condensed on the surface for about 20 minutes and then removed slowly.

 

[flat5]

https://www.theguardian.com/technology/2014/apr/27/electric-paint-bare-conductive-paintable-wire

CONDUCTIVE PAINTS AND INKS
https://www.kobakant.at/DIY/?p=634