Infra-Red Remote Controls: What to Do When they Don't Work

 Editor's Note: I've reproduced this article from a guide I put together recently for my website on what to do if your remote dies on you, or gets damaged or lost. You can download this as a .pdf version - this also contains some useful illustrations. It's available via this link.

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Introduction

One of the most essential, and also potentially annoying, modern inventions is the infra-red remote control. Virtually every electronic device we use nowadays comes with a dedicated remote of some sort, and a lot of the more recent models have been designed so that they won’t work at all without it.

Many of us have already suffered the consequences of this clever move on the part of the manufacturers after we’ve either a) lost the remote for our TV or b) one of the kids has broken it or c) the dog has taken a bite out of it (or the cat's been sick on it - moggies are never blameless!).

The resulting lack of a working remote means that, at best, we can only use our TV or other device in ‘basic’ mode using its external buttons, and we will have lost access to many of the more advanced features many of these devices now offer. At worst, the device may be totally dependent on its remote and has no ‘side buttons’ capable of operating it, whereupon it’s effectively rendered useless.

When challenged, manufacturers assure us that this cleverly-promoted trend towards 'remote dependence' has all been for our own benefit. They insist that removing surplus buttons and other external controls has allowed them to miniaturise their devices and make them cheaper, more powerful and easier for us to use. The real reason, of course, is that they want us to buy their latest product and discard our old one, and would love us to repeat the exercise as often as possible to enhance their sales figures and profit margins. What better way of 'encouraging' us do this for them than by ensuring that their nice new product is totally dependent on a fragile piece of plastic which is easily destroyed or lost ?

Sadly, there’s very little we can do about product design or bad manufacturer behaviour, except vote with our feet (or rather our credit cards) by refusing to buy anything that depends entirely on its remote.

What we can do, though, in most cases, is to find an alternative way of controlling our ‘old’, but still perfectly functional, devices, and thus continue using them…and save ourselves hard earned cash into the bargain. Read on to find out how....

But before you rush off to try and replace your old remote, do check out the Appendix to see if your non-working remote is really dead, or just requires some much-needed tlc to get it going again….

 

Infra-Red Light as a way of controlling devices

Before exploring the practicalities of repairing or replacing Infra-Red (IR) remotes, let's just take a quick look at how they actually work.

The human eye can see only a limited range of wavelengths in the electromagnetic spectrum. This visible range lies between 4000 and 8000 Angstroms (for those who like really small numbers, 1 Angstrom = 10^-10 meters, thus the upper limit of our visible range is light that has a wavelength of 0.0000001 mm!)

The infra-red region of the spectrum lies immediately above the visible range, between 7800A and 10000A, with the most widely used wavelength by IR remotes being around 9300A. This is why you can’t actually see the light your remote emits when it sends a signal to your TV. Interestingly, though, your mobile phone’s camera can detect it, since most of the CMOS displays used in phones are sensitive to light in the near IR region. This gives you an easy way to check whether your remote is really ‘dead’ or just needs a new battery (see Appendix). It also allows you to check out individual keys if any appear to be malfunctioning.

How is information transferred from a remote control to your device ?

The average ‘smart’ digital TV set nowadays is a complex beast – even an old ‘HD ready’ i.e. ‘dumb’ set can have as many as 30 or more different buttons on its remote and will also rely on sub-menus to access some of its functions. Smart TVs are even more complicated and thus require more function controls to use them fully. Some of them have even started to use Bluetooth and Wifi signals to control them as a substitute for IR, which makes them more amenable to smartphone app based control.

To instruct your TV or other device to do something, the remote must send it a message to tell it which function to perform. This must also be specific for that function i.e. each remote key must have a unique code associated with it, which the device’s circuitry can recognise as a specific instruction. There are a number of encoding methods, but all rely on emitting a series of short IR light pulses which vary in length and spacing. The device itself must also have a built-in IR detector capable of receiving the incoming signal and passing it to the device's processor to interpret and act on.

One of the problems an IR communication system of this type has to overcome is stray light – all objects at normal ambient temperatures will emit some IR radiation, and this environmental ‘noise’ must be filtered out by the circuitry. In practice the light beam is modulated at a relatively high ‘carrier’ frequency (ca 38kHz) to enable the receiving circuit to distinguish it from background (i.e. un-modulated) IR. The coded message for the particular key being pressed is then superimposed on this carrier at a much lower frequency. The built-in IR sensor (normally hidden behind a dark-coloured panel at the front of your TV/other device) can then look specifically for the modulated light beam and then decode the signal superimposed upon it. Having done that, the device’s processor looks for a match within its database of commands, and if it finds one, carries out the appropriate instruction. For anyone interested in more detail on how IR remotes work, follow this link.

The Multiplicity Problem

IR remote technology has been around a long time now, and as you might predict, the number of dedicated remotes still operating out there is huge. Given that each model is unique and has its own set of 20 or more buttons on average, you might feel that trying to duplicate the commands produced by each of these was impossible. Fortunately replacing a lost remote is less difficult than you might think. There is a degree of standardisation in remote encoding, and there are large databases of ‘code sets’ available online for different makes of device. Note that the typical ‘code set’ for a particular device includes individual key codes for the basic range of commands for that device, but may not cover all of the buttons available on the original remote.

‘Universal’ remotes capable of recognising these code sets are widely available, and it’s even possible to ‘teach’ certain types of universal remote specific key functions using your existing dedicated remote if you’ve still got it and it’s still working.

How can I replace the remote for my TV/DVD/BluRay, etc…..?

This depends largely on your circumstances, and what type of solution you're aiming for....

Remote control types

If you’ve lost or broken your remote, the first thing to check is whether replacement dedicated remotes are actually available for your device model. There are a lot of exact replacements and substitutes available, but some of the older remotes may be difficult to source replacements for nowadays. The best place to start your 'quest' is probably eBay.

Dedicated new remotes/substitutes tend to cost upwards of £10. This is probably the easiest method to reinstate control of your device if you don’t mind forking out a bit of extra cash. Do make sure that you get the model number correct and check device compatibility before ordering, though. It’s also best to ensure there’s a favourable returns policy in case the new remote doesn’t actually work when it arrives.

If there’s no obvious guaranteed replacement available online, or you don’t want to risk the cash on something that might not work, consider investing in a good universal remote instead. These are available for a similar price, but beware of cheap Chinese imitations – these are priced temptingly low, usually with free postage, but often either don’t work at all or have a disappointingly small range of compatible models. Instead, I’d recommend the ‘One-For-All’ range of models for ease of operation and comprehensiveness when it comes to device compatibility. These can be had new for £15 upwards, with second hand ones available for as little as £8 on eBay.

Before ‘taking the plunge’ and ordering a universal remote, however, you need to decide whether you’re happy to buy a TV-only model or a multi-device one. The difference is lies in the ability to program the remote to control to operate more than one category of device, and also the facility to switch easily between different devices without selecting a new code set each time you switch. The range of available code sets within the remote's memory also differs – only a multi-device model will have a full range of code sets for DVDs, Blu-Rays, audio systems, etc. (A good compromise model is the URC 7145, which will control up to 4 different categories of device (TV, STB, BluRay or DVD, and Audio) and also has a learning mode - any key changes are confined to the code set in use when the change is made). The real advantage of a universal remote is that provided the device you want to control is branded, you stand a good chance of finding a built-in code set which matches it. Even if you don’t have the original remote, or it’s not working, you’ll still be able to get your device working again, albeit with fewer functions available.

If you do still have an original remote that works, you’re probably in the best position of all. Even if you can’t find an appropriate code set for a device, or some of the functions are missing, you can replace these. Most of the One-For-All range models also have a ‘learning’ mode such that you can teach it new codes to duplicate any functions that don’t appear in the basic code set provided, using your existing remote. It’s worth taking the trouble to locate a suitable code set for your device while the original remote is still working – as discussed above, you never know when it’s going to come to a sticky end….

The worst case scenario is probably when you acquire an unbranded model or one with a retail chain brand e.g. Goodmans, Argos, Matsui, and don’t get a remote with it. These devices are quite easy to come by cheaply second hand, but tend to have been manufactured to order under contract, and it can prove virtually impossible to track down the manufacturer several years down the line to request substitute code sets if they aren’t listed. If you’re in this position, the only option is to try the ‘Search’ option if the universal remote provides one, and hope that it yields a suitable code set. If you've invested in a One-for-All model, you also have the option of 'consulting the oracle' - they will usually be able to tell you whether your URC model has a suitable code set or not.

Smartphone-Based Solutions

If you’re not keen on Universal remotes or aren’t sure which type to go for, there is an alternative solution.

Some older types of smartphone have what’s called a built-in ‘IR Blaster’. This is effectively an IR emitting LED of a similar type to that used in remote controls, and is capable of sending out coded pulses superimposed on a carrier, in a similar way, as discussed above. If you’re lucky enough to have one of these devices already, you’ll have access to a range of apps designed to duplicate universal IR remotes. For comprehensive coverage of a large range of devices and brands, I’d recommend the ‘IRPlus’ app, earlier versions of which are compatible with android smartphones with OS versions as early as v4.1. The app will also allow multi-device control with easy switching between different devices. 

The one thing the apps can't do with your smartphone unfortunately is to replicate the 'learning' function available with some universal remotes. This is because additional circuitry is required to detect, and then demodulate, the 38KHz carrier signal, and this isn't normally available within your phone.

There are a wide range of smartphone models which offer IR blasters, though many of these are older models and may only be available second hand nowadays. Follow the link to see whether you already have one. The best places to start looking for a second hand model are probably eBay or Vinted.

Final Thoughts

 I hope this short article on the trials and tribulations of replacing lost or broken remotes may help anyone thus afflicted. The take home message is…don’t despair, there are remedies at hand to enable you to continue using your favourite device even if it’s remote really is dead. Above all, don’t just take it to the nearest skip and shell out for a new one……you’ll be falling into the manufacturer/retailer’s ‘trap’ if you do.

And don’t forget to protect your remotes while they’re still alive and kicking.…dogs and kids love destroying these tempting little electronic morsels, so be warned…..either hide them or lock them up (the remotes, not the kids, that is!)

First published 23.7.25; Updated 2.8.25

Appendix: Simple Fault Diagnostics for Your Original Remote

Remote controls are dependent on a reliable source of power, and like many other electrical appliances, suffer the same problems with intermittent and corroded contacts and internal circuitry. This can lead you to presume your remote is dead when it isn’t…..

Here is a list of things to check before you declare ‘time of death’ on your existing remote:

1)      *Turn on your smartphone and activate its camera app. Point the LED end of your remote at the camera lens and press several of the remote’s keys in succession. If you see a brief violet-coloured flicker each time in the phone’s display, the remote is still working, and the fault may lie elsewhere. (NB some remotes also have a visible LED indicator – always check the actual IR LED before assuming all is well.)

2)      *If you see no flickering light at all, open the remote’s battery compartment and remove the batteries. If you have a multimeter, it’s useful at this stage to check each battery’s output voltage – for AA and AAA single-use types it should be around 1.5v; for rechargeables it should be around 1.2v. If any of the cells are low, or you don’t have a meter, replace them with a set you know are good, or recharge them.

3)      *Before you replace the batteries, check the contacts within the battery compartment. These often get corroded, particularly in damp environments, and this can prevent current flow. (This is quite normal, and can occur wherever 2 different metals make contact in the presence of liquid water). Take a screwdriver or nail-file and gently scrape the contacts, wipe them to ensure they are clear of debris, then replace the batteries. Now repeat the Camera test described in point 1).

4)      *If you still see no response from the LED in this test, and this occurs with a range of different keys, you’ve probably got a dead remote on your hands. If only some of the keys appear dead, you may benefit from a keyboard contact clean – see next heading.

5)      *Keyboard contact clean: Although some remotes are sealed shut with adhesive, most of them aren't, and instead have small internal lugs to keep the case closed. This should allow you to get them open. I’d recommend using a plastic tool of some sort to prise open one side and work round the case, taking care not to cut yourself. Once you have the remote open, make a note of where everything goes before you disassemble it (take a photo if necessary!).

6)    Note the carbon composite contact buttons behind the keyboard and the matching contacts for each key on the circuit bar.

7)      *Clean each of the black buttons (rubbing alcohol is a useful solvent for this) and each of the corresponding circuit board contacts. Take care not to damage any of the connecting strips on the board, as these are virtually impossible to repair). Reassemble the remote, re-insert the batteries and test each key.

With any luck, you’ll now have a fully functioning remote again.....