I don't know where to ask this question, so I will ask it here... Please tell me to take it somewhere else if it is not a simple question.
A friend of mine at the office has been using my QFR with blues. Today he showed me that some of the key presses are not registering. The ones that are really noticeable are: 5, t, b and left alt. I noticed right away that 5, t, b are probably on the same matrix line. Left alt is another story, but that key gets used a lot because he is using the keyboard on a mac (so its his command key).
So to the question. How do I troubleshoot the problem? I am guessing there is a problem with a couple solder joints are something like that. It works a lot of the time, but periodically it misses a key press. Some of those keys are worse than others. Should I unsolder those switches and then resolder them and see if that fixes the problem? Anything I can test with a multimeter which would help diagnose where the problem stems from?