remote control repair

[_defaullt]

My TV remote sees a lot of use and last winter the buttons had to be
pressed very firmly to get them to work. As the weather turned cool
this year, some functions were impossible to get working.

Usually I just replace the remote since the cost is relatively minor,
but without a "mute" button I won't even turn on a TV set, so it was a
matter of waiting for the replacement before I'd use the TV...

I pulled the gizmo apart and there's only one surface mount chip, a
few caps and the IR emitter. The board had a film of oil on it
(presumably skin oil migrates through the rubber membrane?)

The oil was clear colorless odorless and very viscous at room
temperature.

To bring the remote back to like new performance (sans the lettering
that wore off long ago) was a simple matter of heating some water very
hot (subjectively) and immersing the whole thing in a strong solution
of dish washing liquid detergent, letting it soak for a few minutes,
brushing the board and keypad with a toothbrush, rinsing under the
tap, patting dry with a paper towel, then drying the parts in a warm
oven for several hours.

I did have to reprogram the TV code since this was a DTV converter box
remote, and while it holds the code long enough to put in fresh
batteries (for hours in fact) apparently dunking in water discharges
the cap across the battery.

 

[Tom Biasi]

On 9/26/2013 10:02 AM, _defaullt wrote:

My TV remote sees a lot of use and last winter the buttons had to be
pressed very firmly to get them to work. As the weather turned cool
this year, some functions were impossible to get working.

Usually I just replace the remote since the cost is relatively minor,
but without a "mute" button I won't even turn on a TV set, so it was a
matter of waiting for the replacement before I'd use the TV...

I pulled the gizmo apart and there's only one surface mount chip, a
few caps and the IR emitter. The board had a film of oil on it
(presumably skin oil migrates through the rubber membrane?)

The oil was clear colorless odorless and very viscous at room
temperature.

To bring the remote back to like new performance (sans the lettering
that wore off long ago) was a simple matter of heating some water very
hot (subjectively) and immersing the whole thing in a strong solution
of dish washing liquid detergent, letting it soak for a few minutes,
brushing the board and keypad with a toothbrush, rinsing under the
tap, patting dry with a paper towel, then drying the parts in a warm
oven for several hours.

I did have to reprogram the TV code since this was a DTV converter box
remote, and while it holds the code long enough to put in fresh
batteries (for hours in fact) apparently dunking in water discharges
the cap across the battery.

You probably only had to clean the keypad contact areas with alcohol or
other contact cleaner and spare your board from any minerals you may
have in your tap water.

 

[_defaullt]

On Thu, 26 Sep 2013 10:48:39 -0400, Tom Biasi <tombiasi@optonline.net>
wrote:

On 9/26/2013 10:02 AM, _defaullt wrote:
My TV remote sees a lot of use and last winter the buttons had to be
pressed very firmly to get them to work. As the weather turned cool
this year, some functions were impossible to get working.

Usually I just replace the remote since the cost is relatively minor,
but without a "mute" button I won't even turn on a TV set, so it was a
matter of waiting for the replacement before I'd use the TV...

I pulled the gizmo apart and there's only one surface mount chip, a
few caps and the IR emitter. The board had a film of oil on it
(presumably skin oil migrates through the rubber membrane?)

The oil was clear colorless odorless and very viscous at room
temperature.

To bring the remote back to like new performance (sans the lettering
that wore off long ago) was a simple matter of heating some water very
hot (subjectively) and immersing the whole thing in a strong solution
of dish washing liquid detergent, letting it soak for a few minutes,
brushing the board and keypad with a toothbrush, rinsing under the
tap, patting dry with a paper towel, then drying the parts in a warm
oven for several hours.

I did have to reprogram the TV code since this was a DTV converter box
remote, and while it holds the code long enough to put in fresh
batteries (for hours in fact) apparently dunking in water discharges
the cap across the battery.

You probably only had to clean the keypad contact areas with alcohol or
other contact cleaner and spare your board from any minerals you may
have in your tap water.

I used to do instrument repairs in a laboratory; if the clumsy
analyst was quick to turn it off or unplug it after spilling stuff
down in the keyboards I could usually fix it by washing in distilled
water and drying it in a vacuum oven.

Same technique I'd use on my motorcycle's non-waterproof radar
detector when it rained.

Mp3 players kayaking? ditto. The only thing that seems to matter is
that the power be removed ASAP!

As long as it is dry I don't think minerals matter. I suppose if you
had minerals/salts that are hygroscopic in nature and the humidity is
high...

 

[Shaun]

"Tom Biasi" wrote in message news:3OX0u.76703$ey4.4681@fx02.iad...

On 9/26/2013 10:02 AM, _defaullt wrote:

My TV remote sees a lot of use and last winter the buttons had to be
pressed very firmly to get them to work. As the weather turned cool
this year, some functions were impossible to get working.

Usually I just replace the remote since the cost is relatively minor,
but without a "mute" button I won't even turn on a TV set, so it was a
matter of waiting for the replacement before I'd use the TV...

I pulled the gizmo apart and there's only one surface mount chip, a
few caps and the IR emitter. The board had a film of oil on it
(presumably skin oil migrates through the rubber membrane?)

The oil was clear colorless odorless and very viscous at room
temperature.

To bring the remote back to like new performance (sans the lettering
that wore off long ago) was a simple matter of heating some water very
hot (subjectively) and immersing the whole thing in a strong solution
of dish washing liquid detergent, letting it soak for a few minutes,
brushing the board and keypad with a toothbrush, rinsing under the
tap, patting dry with a paper towel, then drying the parts in a warm
oven for several hours.

I did have to reprogram the TV code since this was a DTV converter box
remote, and while it holds the code long enough to put in fresh
batteries (for hours in fact) apparently dunking in water discharges
the cap across the battery.

You probably only had to clean the keypad contact areas with alcohol or
other contact cleaner and spare your board from any minerals you may have
in your tap water.

If the whole inside of the remote had a film so something inside of it; a
soak on 50% distilled water and 50% high purity alcohol would have done it
with a gentle scrub, then let it all dry. Dish washing chemicals could have
eaten away at the circuit board, bad idea. I use a contact cleaner and a
swab to gentle clean the contacts on the board and the conductive rubber on
the keypad. If you clean the conductive rubber pads too much, you'll remove
the conductive layer. I like to use Super Contact Cleaner by MG Chemicals,
it leaves a thin layer the protects the contacts from oxidation and improves
the conductivity. You can buy kits for replacing the conductive coat on the
rubber keyboard.

 

[_defaullt]

On Thu, 26 Sep 2013 10:28:48 -0500, "Shaun" <stereobuff07@gmail.com>
wrote:

"Tom Biasi" wrote in message news:3OX0u.76703$ey4.4681@fx02.iad...

On 9/26/2013 10:02 AM, _defaullt wrote:
My TV remote sees a lot of use and last winter the buttons had to be
pressed very firmly to get them to work. As the weather turned cool
this year, some functions were impossible to get working.

Usually I just replace the remote since the cost is relatively minor,
but without a "mute" button I won't even turn on a TV set, so it was a
matter of waiting for the replacement before I'd use the TV...

I pulled the gizmo apart and there's only one surface mount chip, a
few caps and the IR emitter. The board had a film of oil on it
(presumably skin oil migrates through the rubber membrane?)

The oil was clear colorless odorless and very viscous at room
temperature.

To bring the remote back to like new performance (sans the lettering
that wore off long ago) was a simple matter of heating some water very
hot (subjectively) and immersing the whole thing in a strong solution
of dish washing liquid detergent, letting it soak for a few minutes,
brushing the board and keypad with a toothbrush, rinsing under the
tap, patting dry with a paper towel, then drying the parts in a warm
oven for several hours.

I did have to reprogram the TV code since this was a DTV converter box
remote, and while it holds the code long enough to put in fresh
batteries (for hours in fact) apparently dunking in water discharges
the cap across the battery.

You probably only had to clean the keypad contact areas with alcohol or
other contact cleaner and spare your board from any minerals you may have
in your tap water.

If the whole inside of the remote had a film so something inside of it; a
soak on 50% distilled water and 50% high purity alcohol would have done it
with a gentle scrub, then let it all dry. Dish washing chemicals could have
eaten away at the circuit board, bad idea. I use a contact cleaner and a
swab to gentle clean the contacts on the board and the conductive rubber on
the keypad. If you clean the conductive rubber pads too much, you'll remove
the conductive layer. I like to use Super Contact Cleaner by MG Chemicals,
it leaves a thin layer the protects the contacts from oxidation and improves
the conductivity. You can buy kits for replacing the conductive coat on the
rubber keyboard.

I dunno. I think we tend to rope ourselves into the idea that
everything has to be high tech to work properly. Pity there's no
study done.

The conductive coatings? Often cost more than the cost of a remote or
two, don't adhere all that well to the contact buttons so you wind up
with a lot of conductive particles laying around. I tried that route
years ago figuring I could repair remotes indefinitely with the 1/4
ounce in the kit.

Some guy is making a fortune buying up surplus aquadag coating paint
by the gallon and repackaging it in DIY contact repair kits would be
my guess.

One method that works is to just rub the conductive buttons over a
very very fine sandpaper.. but that just exposes a fresh
uncontaminated surface, wears away at the conductive buttons, and does
nothing to address films on the board surface. But it does work for a
time.

Corrosive properties of dishwashing liquid? A surfactant like sodium
laurel sulphate, some thickening agent, coloring, and perfume, and it
all has to be relatively benign and non-toxic because it is intended
for consumer use in hot water and the time it takes to wash dishes.
Some dishwashing liquids are advertised as suitable for hand/body wash
dispensers too.

But then I still use WD-40 for a corrosion protection coating and
there's lots of folks saying it won't work. I first used it on one of
the old turret TV tuners back in the 60's and have been using it on
potentiometers (to cure noisy pots) and contacts ever since, with no
noticeable ill effects. (it's hell on rubber bands though)

 

[Phil Allison]

"_defaullt"

Corrosive properties of dishwashing liquid? A surfactant like sodium
laurel sulphate, some thickening agent, coloring, and perfume, and it
all has to be relatively benign and non-toxic because it is intended
for consumer use in hot water and the time it takes to wash dishes.
Some dishwashing liquids are advertised as suitable for hand/body wash
dispensers too.

** Ordinary liquid dish washing ( not dishwasher) detergent is harmless to
PCBs and the components theron. Rinsing in clean, warm water is all you need
to do and then thoroughly dry - same as factories do now when dealing with
water soluble fluxes.

The one exception is those PCBs that have old style flux all over the
lace - them you have to soak in solvent and get all traces of the flux
off. I use methylated spirits in an old frying pan - it takes two lots of
solvent usually.

Otherwise, water infuses into the flux and makes the PCB conductive - you
can tell this if the flux becomes milky looking.

But then I still use WD-40 for a corrosion protection coating and
there's lots of folks saying it won't work. I first used it on one of
the old turret TV tuners back in the 60's and have been using it on
potentiometers (to cure noisy pots) and contacts ever since, with no
noticeable ill effects.

** The rabid anti WD40 brigade are all lunatics. The various alternatives
they swear by are either damn near useless or damn near the same as WD40 -
but at several times the price.



.... Phil

 

[David Eather]

On Fri, 27 Sep 2013 14:59:48 +1000, Phil Allison <phil_a@tpg.com.au> wrote:

"_defaullt"

Corrosive properties of dishwashing liquid? A surfactant like sodium
laurel sulphate, some thickening agent, coloring, and perfume, and it
all has to be relatively benign and non-toxic because it is intended
for consumer use in hot water and the time it takes to wash dishes.
Some dishwashing liquids are advertised as suitable for hand/body wash
dispensers too.


** Ordinary liquid dish washing ( not dishwasher) detergent is harmless
to
PCBs and the components theron. Rinsing in clean, warm water is all you
need
to do and then thoroughly dry - same as factories do now when dealing
with
water soluble fluxes.

The one exception is those PCBs that have old style flux all over the
lace - them you have to soak in solvent and get all traces of the flux
off. I use methylated spirits in an old frying pan - it takes two lots
of
solvent usually.

Otherwise, water infuses into the flux and makes the PCB conductive -
you
can tell this if the flux becomes milky looking.


But then I still use WD-40 for a corrosion protection coating and
there's lots of folks saying it won't work. I first used it on one of
the old turret TV tuners back in the 60's and have been using it on
potentiometers (to cure noisy pots) and contacts ever since, with no
noticeable ill effects.

** The rabid anti WD40 brigade are all lunatics. The various alternatives
they swear by are either damn near useless or damn near the same as
WD40 -
but at several times the price.



... Phil



A question - I don't have an answer but would like to know - how does
that phenolic PCB crap recover after soaking? I'm guessing it's OK but
takes longer drying if your circuit is high impedance?

 

[Shaun]

"Phil Allison" wrote in message news:bakhmaFo5hsU1@mid.individual.net...


"_defaullt"

Corrosive properties of dishwashing liquid? A surfactant like sodium
laurel sulphate, some thickening agent, coloring, and perfume, and it
all has to be relatively benign and non-toxic because it is intended
for consumer use in hot water and the time it takes to wash dishes.
Some dishwashing liquids are advertised as suitable for hand/body wash
dispensers too.

** Ordinary liquid dish washing ( not dishwasher) detergent is harmless to
PCBs and the components theron. Rinsing in clean, warm water is all you need
to do and then thoroughly dry - same as factories do now when dealing with
water soluble fluxes.

The one exception is those PCBs that have old style flux all over the
lace - them you have to soak in solvent and get all traces of the flux
off. I use methylated spirits in an old frying pan - it takes two lots of
solvent usually.

Otherwise, water infuses into the flux and makes the PCB conductive - you
can tell this if the flux becomes milky looking.

But then I still use WD-40 for a corrosion protection coating and
there's lots of folks saying it won't work. I first used it on one of
the old turret TV tuners back in the 60's and have been using it on
potentiometers (to cure noisy pots) and contacts ever since, with no
noticeable ill effects.

** The rabid anti WD40 brigade are all lunatics. The various alternatives
they swear by are either damn near useless or damn near the same as WD40 -
but at several times the price.



.... Phil

Regular warm water on a PCB when it dries may leave behind contaminates that
were dissolved in the water, not a good idea. You'll want to rinse the
board before it dries with distilled water, a good flush of distilled
water - then let it dry. You may want to use a gentle heat source under the
whole thing too because the water can get trapped under some components and
it won't evaporate at the same rate as the rest of the board. I have seen
damage to pcbs from water getting into the electronics and I would have to
scrub away the contaminates left from the water using distilled water and
iso-propyl alcohol and a few cotton swabs. I have also seen water trapped
under components after the board sat in open air for at least 24 hrs.

Shaun

 

[Phil Allison]

"Shaun"

"Phil Allison" "_defaullt"

Corrosive properties of dishwashing liquid? A surfactant like sodium
laurel sulphate, some thickening agent, coloring, and perfume, and it
all has to be relatively benign and non-toxic because it is intended
for consumer use in hot water and the time it takes to wash dishes.
Some dishwashing liquids are advertised as suitable for hand/body wash
dispensers too.


** Ordinary liquid dish washing ( not dishwasher) detergent is harmless to
PCBs and the components theron. Rinsing in clean, warm water is all you
need
to do and then thoroughly dry - same as factories do now when dealing
with
water soluble fluxes.

The one exception is those PCBs that have old style flux all over the
lace - them you have to soak in solvent and get all traces of the flux
off. I use methylated spirits in an old frying pan - it takes two lots
of
solvent usually.

Otherwise, water infuses into the flux and makes the PCB conductive - you
can tell this if the flux becomes milky looking.


Regular warm water on a PCB when it dries may leave behind contaminates
that were dissolved in the water,

** Dunno what shit water you drink - but Sydney's tap water leaves no
residue.

> not a good idea.

** Says who ?


> You may want to use a gentle heat source under the whole thing too ...

** When I said "dry thoroughly " I meant it.




..... Phil