This isn't actually a repair, but instead is a modification of a new device so that it can be used as a replacement for an existing broken one.
A normal dimmer switch is modified to provide two outputs, one dimmed and the other not dimmed. This is for a particular application in a kitchen, where the dimmer output is used for three 50W halogen lamps on the ceiling, and the undimmed output is for a set of fluorescent tubes fixed the wall units to illuminate the worktop.
WARNING: This involves mains voltage. The dimmer shown is just one of many types available, others are likely to be different inside, and if unsure in any way, do NOT attempt such modifications yourself. This is a record of how this particular item was modified, it is NOT a guide or instructional.