Remote control: Repairing broken traces/connections

This guide applies generally to all remote controls and is therefore kept in general, fundamental terms.

It is not uncommon for several buttons on a remote control to stop working because the conductive traces on its PCB leading to the remote control's IC are interrupted, or breaks have occurred at its solder connection.

For your understanding: as a rule, the buttons of a remote control are connected in a matrix pattern to the terminals of the IC. This means that typically not just one button fails, but a group of buttons; especially if adjacent or vertically aligned buttons fail, this points to such a defect.

First, you must open the remote control. The housings are usually clipped together, and there is often a screw in the battery compartment. Release the screws and carefully pry at the seams with a knife, screwdriver, or similar tool until you have unclipped the housing halves. How this works is an individual case.

Then, analyze the conductive traces of the affected buttons. The crucial part is the conductive trace that supplies all or a group of the affected buttons. If the defect is here, you can recognize it by the fact that these traces have no connection to any terminal of the IC, while this is the case for other traces.

Typically, the traces are covered with a mostly greenish protective layer (solder mask). You must, of course, carefully scrape this off before measuring with an ohmmeter (remove the batteries from the remote control first). Less is more here, as you must not break the conductive trace under any circumstances.

Once you have identified interrupted traces, the question arises as to which pin of the IC they must be connected to. First, you must check all terminals of the IC to see if they are conductively connected to another component or a group of buttons. For the remaining terminals that are not clearly connected, you have to guess.

Sometimes you can plausibly guess the correct connections based on the position of the traces and terminals; this is a matter of experience. If not, you just have to guess and try it out. As a rule, however, you cannot break anything.

The electrical connection is made using very thin insulated wire, such as thin enameled copper wire from 0.1 to 0.5 mm. Standard plastic-insulated stranded wire is usually too thick. Since the conductive traces are very fine, you must have some experience in electronics soldering; I cannot explain this here. The appropriate tool is required.

I also cannot explain how to perform the soldering here; anyone who is not already able to perform fine electronics soldering should keep their hands off these repairs, as they will destroy the PCB in the process. You do not necessarily need experience in SMD soldering—but it helps, also because of the required tool.