View Single Post
  #10   Report Post  
Posted to sci.electronics.repair
Three Jeeps Three Jeeps is offline
external usenet poster
 
Posts: 18
Default What is this stuff?

On Monday, May 31, 2021 at 7:28:48 AM UTC-4, Miguel Giménez wrote:
El 29/05/2021 a las 23:55, micky escribió:
Someone on Freecycle gave me a nice tv, pretty old, but comelete with
owners manual and remote control.

The remote works fine except for the buttons used the most, volume up
and down, channel up and down, power, and muting.

I took it apart and expected to find oxidized contact points, but no.
Instead those buttons, on the circuit board and on the buttons, are
shiny and a little bit sticky. I forced myself to taste it, but I don't
taste anything.

3 other buttons have a little of those, but no more than 4% of any
button.

What is this, how does it get in there, and [what do I do about it}?

I have DeoxitIT, what I've read is the best, but I guess I've never used
it before, and it didn't remove the stickiness. Not only that, these
contacts aren't copper-colored, and as the name impplied, it's really to
remove and prevent oxidization, so I switched to isopropyl alcohol and
that did a good job.

So I know what to do about it, but what is that stuff? Finger oil?

It's silicon grease, exudated by the silicone keys due to a bad
fabrication process. Pressure on the keys make this grease flow, then
the contact begins to fail needing more pressure, more grease flows...
That's why the keys used more often fail more than those seldom used.

You can clean it with ethanol, it will work for some months before
needing another cleaning.

--
Saludos
Miguel Giménez

Exactly. I've services quite few of these and used 80% isopropal or ethel alcohol. Just wash the entire silicon keypad in the solvent. I've found it usually last about a year before it needs to be done again.
I had a small panasonic TV that sat on our kitchen table that had its remote control sit next to it. Had to wash the key pad about every 9 months...it was usually in the sunlight from the skylight which I think the UV light accelerated the release of the grease.
Good luck
J