HOW TO TEST AND CLEAN A REMOTE CONTROL
Remote
control handsets of most of the electronic devices will get damaged after some
time. Some of them can be set right by cleaning the remote control. Remote
handsets of some devices will be not available to get from the open market or
even from the service centers of the producers. In such cases, cleaning them
may get it to work.
Normally,
all infrared type remote controls are made up of silicon rubber touch pads.
Each touch button in it will have a small carbon button inside it, which comes
in contact with the carbon track on the internal circuit board. These carbon
tracks are connected to various pins of an IC [Integrated Circuit] on the
remote's circuit board. For each button touch, generates signals of different
frequency, which in turn activates the infrared LED [Light Emitting Diode],
which emits infrared light waves of the same frequency. This infrared light
waves are received at the device to which controlled [whether it is a TV, DVD,
VCR, DVR etc:]. There is an infrared receiver inside the device, usually called
"remote sensor", which receives this signals, convert it to
corresponding frequency signals, and processed by the main system control IC
inside the device and controls it.
Generally,
the remote handset can be called a neglected device. The customer will give no
extra care to it. The batteries in the remote control will get damaged after
one to two years. It will finally get leaked and the electrolyte in the battery
will get in contact with the battery contacts at the battery compartment. This
electrolyte will react with metal contacts at the battery compartment that in
turn supplies the battery voltage to internal circuits of the remote control
handset. If these contacts get rusted due to this electrolyte contact, supply
line to the remote control will be interrupted and the remote control will be
dead, even after replacing it with new batteries. First thing to check with for
a dead remote is this battery contacts. If there is rust or dirt accumulated,
clean them using anything like a razor blade, very small file [seen with some
nail cutters]. If the fault was due to battery contact, this process of
cleaning will rectify the problem.
To
clean the inner circuits of the remote control, you have to open the remote
control. Most of the remote controls' case is 'press fitted' with lower and
upper case parts. There may be 4 to 6 of such locks. Some remotes will have
screws also. Detach the lower and upper case, by using any sharp tool. A guitar
pick will be efficient to do this work. Just look for the locks at one side,
press the lock position inwards and try to lift up or pull out the case part.
Do this work with caution and patience. Never try to get it apart quickly. Get
the case open without breaking it.
Inside
the remote control, you can see a printed circuit board, with carbon tracks,
and IC two or three other components, and an infrared LED. Check the soldering
terminals of the infrared LED [two soldering] for any loose solder. If loose
solder is detected, re-solder that points by applying a little more solder.
Cleaning
should be done very carefully. Never use strong solvents like petrol. Rectified
spirit is most preferable. Medical quality turpentine can also be used. This
can be bought from most of the medical shops. Just dip a piece of soft cloth in
these solvents, and wipe out the carbon track and inside of the touch pad. If
you use petrol for this purpose, the rubber part of the touch pad will get
damaged and will turn sticky. After clean up, let it dry under a fan for some
time. Reset the unit as it was before. If no other damage to IC or other
components, the remote control should work properly
