Kawai K3m
The repair of this module was quite simple, but very time-consuming. I had to replace all the switches on the control panel – 61 pieces. This would not be difficult if the solder holes for the microswitch pins were not so small. The panel board is double-sided, so even with a desoldering station it was very hard to remove them.
Luckily, I always have special low-melting Wood’s alloy (ChipQuik), which makes this kind of difficult desoldering possible. Also, the original microswitches had square heads with a size of 2.6 × 2.6 mm, while the new ones made today have 2.4 × 2.4 mm. This 0.2 mm difference caused the plastic buttons on the control panel to fit too loosely and not hold well.
I had to use a small amount of flexible glue on each of them. Why flexible? So it can be easily removed if the switches need to be replaced again. In other words, the repair was simple in theory, but very labor-intensive.
