How to open up your faulty Logik IR100 Internet Radio to replace the rotary encoder

 Before we start it must be emphasised that all electronic devices are fragile and more so when they are opened. In particular you must ensure that the radio is unplugged from the mains (doh!) before you start. Inside the radio is a power supply board on this are several capacitors. These are really batteries that hold a charge (of several AMPS) for hours if not days. Many people do not believe this but whilst a shock from a charged capacitor will not be deadly the flash and loud crack when you accidentally short it out can easily cause your screwdriver to slip resulting in serious damage to the radio – or you if you stick it into your thumb! Fortunately you will not be dealing with power supply faults (nor should you if you are inexperienced) so you can heed this advice and move on.

WE DO NOT READ, NOR DO WE EVER FOLLOW INSTRUCTIONS SUCH AS THESE. AFTER ALL WE “KNOW IT ALL”! IF YOU CHOSE TO GO AHEAD WITHOUT HEEDING THESE WARNING THEN WHO ARE WE TO COMPLAIN – BUT DON’T SAY WE DIDN’T WARN YOU!

The Logik IR100 Internet Radio is made to a modular design with five or six different boards screwed together with interconnections using ribbon cables that are plugged in. One end of each ribbon cable is soldered into its circuit board and the other has a plug which fits into a corresponding socket on another board. Once you have the radio open the first thing to do is look carefully where each plug goes – they can look similar if you have not taken a careful look before starting. One idea is to write on each cable with a unique mark try using a pencil or a felt tip. There is also a loudspeaker plug which connects to the main power board. This especially MUST be reconnected before reconnecting the mains or you may blow the 8Watt amplifier.

It will immediately become apparent that the construction of this radio is cheap – very cheap! For example the end of each wire that is soldered into the board should use a special connector which stops strain on the wire when you pull the plug on the other end. On the Logik they have chosen to simply use some glue to “reinforce” the soldered end! Pull too hard, or even flex the wire too much and there is the real chance that you will break a wire inside the plastic covering at the soldered end, so be gentle.

Experienced radio and television engineers are well used to know how much they can pull a wire without it breaking, if this is your first attempt at a repair then use the rule of pulling just as little as you can and BE CAREFUL! IF you break a wire then on no account reconnect the mains supply “to see if it still works” as you run the real risk of damaging your radio. Mend the break first! The micro controller board (which looks different to the others as it is a different colour and well made) is really a small computer so break that and expect a large bill to get it fixed – probably more than the radio is worth!

Right, all the warnings out of the way and if we haven’t put you off you can go ahead with the instructions (or actually really suggestions) as to how you can get at the encoder board to replace the rotary control.

The first job is to remove the large knob on the front that is attached to the encoder that you are later going to remove and then solder its replacement in to place. Some people like to quite literally get the knob out of the way first; others like to leave it until later. Either way this has to come off some time and its removal is probably the hardest part of the whole repair. If yours does not come away with a sharp tug or two perhaps wait a bit until later when we will make some suggestions how to make the job easier.

As you will guess the encoder is right at the front of the radio so as you go in from the back there is a fair amount of stuff to move to get at it! First remove the six screws holding the back on using a medium size cross head screwdriver that is at least 15 cm long. Most screws will come straight out but at least one, and probably more will get stuck in their mounting however much you turn them. This doesn’t really matter and can be sorted out later. One suggestion is to get a small pot to put all the screws in, you will probably end up with up to 20 screws of different sizes before you start to reassemble so it might be as well to mark them to make sure that you put the right screw back into the right socket.

To help removing the back you can put two fingers into the acoustic dome on the back to get some purchase – do NOT pull on the mains lead, however much you want to, as it is not well held - inside some sets it’s just glued in place! Don’t pull too hard on the back either as there are three wires connected between the modules fixed to the back cover and the rest of the set – pull these too hard and you’ll break the wires! Also beware that some people have bought “faulty” radios on eBay and found a collection of parts inside that are not even plugged together – this has happened at least twice to our knowledge! If you find any of the plugs out of their sockets then be very suspicious of proceeding as if they are that deceitful the seller will obviously blame you for the radio not working!

If you do decide to continue then make sure that you have a full set of boards and not two the same somewhere! The Barracuda computer boards are getting harder to find and there will be a temptation to sell a non-working radio with this missing.

Right back to your “honest” radio. Having pulled the back perhaps an inch or so away carefully look inside the radio and you will see two ribbon cables and one loudspeaker cable stopping your pulling any further. Before proceeding follow our earlier recommendation to look carefully at which plug goes into which socket and write it down somewhere. Two of the cables plug into sockets on boards attached to the back, and one cable has its plug end inside the set. All we can suggest is that you carefully try to separate these plugs starting with the two on the back of the radio. There is some “nail varnish” type stuff which is meant to hold the plugs together – it doesn’t – but it does help show you which way round to reassemble the cables later. To separate try putting your nail under the plastic lip of each plug and socket combination but try not to pull on the cable itself.  Do make sure you’re careful or you’ll not have a working radio after all your trouble! Once you have the three connectors separate you are now able to move the back away from the set.

Next look underneath the set at the front and you will see a single screw – this is the only countersunk screw in the radio so don’t lose it as you can’t swap it with anything else when you put it back together. Remove this screw and you may see a red spacer underneath, if so pull that out and store both safely in your pot.

The front of the set will now come away quite easily (the glue holding it will have dried up) and you will be left with the empty wooden case in one hand and the front panel in the other. If you decided to leave levering off the large knob earlier then you can put it off no longer, so put something onto the plastic to reinforce and act as a fulcrum as well as saving too much damage to the plastic, then with your flat bladed screwdriver lever the large knob off. You are aiming for the screwdriver to engage with the centre of the knob, not the edge which is very thin and will crack with too much pressure. The knob WILL come, but may take a lot of persuasion and some ingenuity to remove. Just keep trying, it’s only plastic! Perhaps try putting something slim and strong to lever against? Sometimes these knobs just drop off (quite literally) as they are only held with a bit of double sided tape, others are held like they have been held on with epoxy resin. There is unfortunately no way out of it, if you want to replace the encoder then to get inside the knob MUST come off - by fair means or foul! Next pull off the volume knob (usually much easier) and you can start to breathe again.

Put the front face down on something to save it getting scratched (a pillow or some foam perhaps?) and start disassembly. Fortunately you do not need to remove all the screws that you can see! There are six to take the bracket that holds the display and other boards off, two are located at the very bottom where they screw through the grey plastic, one is on the edge beside the “dogleg”, and another three at the top. Yes three! In the very corner at the edge is what looks like an ordinary screw but it is about 4 times the length of all the others so keep twiddling! There is one other normal length screw in the other corner and then one more that is hidden under the cable at the top. You don’t need to unplug this cable (at all) just push it gently over and remove the screw. The whole module will now come away in your hand.

Turn it over and you will see the boards with the buttons, controls, and the display – be very careful and do not be tempted to clean the display as it is not made of normal plastic. It is quite soft and marks easily and permanently, leave it well alone! If you MUST remove a bad mark try alcohol and don’t rub too hard.

All you need do now is remove the four short screws that hold the control board in place. You will see two ribbon cables coming from the control board. One goes through the slot and leads right to the back of the set – you must replace the wire through the slot, and the other just goes under the wire leading to the micro control board. This plug needs removing – gently – and make sure than when you come to reassemble you put the wire back under the other. If you don’t keep the cable dressing the same there is a chance that one will get snagged by the case when you come to reassembly. I have done this and broke the cable.

So after two pages of notes you finally have the board that you need in your hand – time to warm up your soldering iron!

There are (at least) two different styles of control board – one original and one modified. Look at the photos to see if your board is the modified variety as some people have found that their replacement encoder works better when the modification is removed. It’s up to you but you might choose to check both ways.

If you do want the modification removed then you will need to take away two resistors (cylindrical components with colour code) and then BRIDGE where they were with pieces of wire. You are replacing the resistors with wire NOT joining where the components were together – hope that’s 100% clear! Also remove the extra capacitor (small brown flat round component) that is next to them. There is a further component in the mod which is a capacitor near where the wire leaves the board. This can stay as it’s difficult to remove but if you wish to by all means do have a go at removing it, entirely at YOUR risk!

Next you need to “simply” unsolder the old rotary encoder using a solder sucker or desoldering braid. Clean the position and replace with the new encoder. Do be aware that the circuit board is of rubbish quality and it is extremely easy to break one or more of the tracks (often invisibly) when you apply heat so get your test meter out and check now, then check again! We have broken tracks even after knowing all this and the breaks are often at the edge of the etching where the modifications have been soldered over. That’s a break underneath the soldering which is not connected - really, really nasty!

If your original encoder did work after a fashion then it might be an idea to desolder it carefully and put is aside safely so if something goes wrong you at least have something to replace to test and see where the problem lies. You could even try opening up the encoder by bending the clips, clean the four contacts with some alcohol, clean the track and reassemble. Until we obtained the replacement encoders that was all that you could do!

After resoldering and checking it’s time to put your radio back together. Now it’s not for us to suggest this but you might prefer to leave the knobs off for now and put the parts back together with the minimum number of screws to check that your radio works before tightening everything together. Up to you and WE did not suggest this – be careful if cutting corners. Be especially careful not to trap the ribbon cables. Break these internally and expect many hours of checking and frustration!

Replace the plugs into their respective sockets making sure you put each in the right way round. It is hard but not impossible to put them in backwards! This is where marking the plugs before disassembly will have helped, if unsure better to wait and ask someone (even us) than ruining your radio at this stage. If after reassembly you find the small black buttons on the front either don’t work at all or need pressing much harder than before to click, you will need to reopen the set and look at the rubber mat which should sit neatly in its place between the buttons and the electrical switches. You will find the mat has moved or perhaps even dropped on the floor without your noticing!

The large knob will next require your attention. If you have been sent an encoder with a round metal spindle then the knob will need very slightly enlarging before it will fit. We use a 6mm drill bit held in a pair of pliers and give a couple of twiddles - in a drill would be too much and would remove too much plastic. The plastic is very, very cheap (so what else is new) and you will only need a couple of turns of your drill to make the knob fit. If you drill too much away don’t worry, a little hot melt glue, or even a piece of sellotape will hold it fine and you will know that next time you fix your radio (as if) you will not have so much difficulty getting it off!

It was discovered early on that the encoder was not really up to the job so some radios were modified in production to stop the encoder causing clicking on the audio when turned and to possibly also make the cheap component last longer. This obviously did not work! If you wish you can try removing the modifications which had a down side effect of making selection slower and less accurate because they "rounded the edges" of the pulses generated by the encoder.

DO NOT REMOVE THE MODIFICATION IF YOUR NEW ENCODER IS WORKING OK