NotTaR of Television Sets : Revival of dead or tired remote control ..  
 Copyright © 1994-2007, Samuel M. Goldwasser. All Rights Reserved. Reproduction of this document in whole or in part is permitted if both of the following conditions are satisfied: 1. This notice is included in its entirety at the beginning. 2. There is no charge except to cover the costs of copying. I may be contacted via the Sci.Electronics.Repair FAQ (www.repairfaq.org) Email Links Page.

     << Static discharge noise an.. |  Index  | Problems with the IR remo.. >>

Revival of dead or tired remote control units

There are two types of problems with hand held remote controls: they have legs of their own and they get abused or forgotten. I cannot help you with walking remotes.

Where response is intermittent or the reliable operating distance is reduced, first check the batteries and battery contacts. If some buttons are intermittent or dead, than the most likely cause is dirty or worn contacts under the rubber buttons or on the circuit board.

If there is no response to any functions by the TV or VCR, verify that any mode switches are set correctly (on both the remote and the TV or VCR). Unplug the TV or VCR for 30 seconds (not just power off, unplug). This sometimes resets a microcontroller that may have been confused by a power surge. Confirm that the remote has not accidentally been set to an incorrect mode (VCR instead of TV, for example). If it a universal type, it may have lost its programming - reset it. Make sure you are using the proper remote if have multiple similar models.

Test the remote with an IR detector. An IR detector card can be purchased for about $6. Alternatively, build the circuit at the end of this document. If the remote is putting out an IR signal, then the remote or the TV or VCR may have forgotten its settings or the problem may be in the TV or VCR and not the hand unit. The following is just a summary - more detailed information is available in the companion document: Notes on the Troubleshooting and Repair of Hand Held Remote Controls.

Problems with remote hand units:

All except (1) and (2) require disassembly - there may be a screw or two and then the case will simply 'crack' in half by gently prying with a knife or screwdriver. Look for hidden snap interlocks.

  1. Dead batteries - solution obvious.

  2. Corroded battery contacts, Thoroughly remove chemical deposits. Clean contacts with pencil eraser and/or sandpaper or nailfile.

  3. Broken connections often between battery contacts and circuit board, possibly on the circuit board - resolder.

  4. Bad resonator or crystal - replace, but diagnosing this without an oscilloscope may be tough. Broken connections on resonator legs are common.

  5. Dirt/spills/gunk preventing keys from operating reliably. Disassemble and wash rubber membrane and circuit board with water and mild detergent and/or then alcohol - dry completely.

  6. Worn or corroded contact pads on circuit board. Clean and then use conductive Epoxy or paint or metal foil to restore.

  7. Worn or dirty pads on rubber keypad. Clean. If worn, use conductive paint or metal foil to restore.

  8. Cracked circuit board - can usually be repaired as these are usually single sided with big traces. Scrape off insulating coating and jumper breaks with fine wire and solder.

  9. Bad LED. If IR tester shows no output, remove LED and power it from a 9 V battery in series with a 500 ohm resistor. If still no output, replace with readily available high power IR LED. Otherwise, check driver circuits.

  10. Bad IC - if it is a custom chip, forget it! Failure of the IC is usually quite unlikely.

    (The following is from Duane P Mantick:)

    An awful lot of IR remotes use IC's from the same or similar series. A common series comes from NEC and is the uPD1986C which, incidentally is called out in the NTE replacements book as an NTE1758. A lot of these chips are cheap and not too difficult to find, and are made in easy-to-work-with 14 or 16 pin DIP packages. Unless you have no soldering or desoldering skills, replacement isn't difficult.

There are a large variety of universal remotes available from $10-$100. For general TV/VCR/cable use, the $10 variety are fine. However, the preprogrammed variety will not provide special functions like programming of a TV or VCR. Don't even think about going to the original manufacturer - they will charge an arm and a leg (or more). However, places like MCM Electronics do stock a variety of original remotes - prices range from $9 - $143 (Wow $143, for just a stupid remote! It doesn't even have high definition sound or anything exotic). The average price is around $40.

 <<Static discharge noise an.. | ToC | Problems with the IR remo..>>