Saturday, December 29, 2012


     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.
                                For more about remote control