Oh dear! This line 6 repair was a bit of a mess – you can see on the right hand side of the pic that the board has been burnt by some over heating rectifier diodes.
Most pedals run from a DC supply, but a lot of line 6 gear uses and AC supply. A popular reason for doing this is to allow the designers to simply create positive and negative DC power rails in the unit. They don’t just do it to confuse guitarists! The AC supply must then be rectified by diodes and filtered with caps to create a DC supply. Its these diodes that were destroyed.
Anyway, I was surprised to see that the diodes on this unit look like 1A packages when the unit is specced for 2A intake. The line 6 repair procedure was therefore to replace these with meaty 3A diodes to prevent further problems. The owner is lucky that none of the sensitive DSP and microcontrollers appeared to have been damaged as these could not have been replaced.
Due to the complex nature of the DSP kit that they use, line 6 repairs can sometimes be uneconomical – whole boards sometimes have to replaced in line 6 repairs. However this line 6 repair was completed in the first hour and was cheap for the customer. If you have a line 6 repair job for me, please get in touch and I’ll try to advise.
Myth avoidance: Pedals made with surface mount technology are not that hard to repair, though very fine pitch SMT can be harder. What is next to impossible is the replacement of DSP and MCU chips. Since I don’t have the code that was loaded onto these I can’t repair them, and so these repairs can only be done by a board replacement.