Hi. I’ve got the K4004b, with k4006 power supply. Problem: no sound from the right channel. The left channel works fine. Weird is that there is an output (VDC) on both channels (nearly equal), but I’ve got only sound from the left channel.
Changing the output (left/right speaker) or the input (left/right) doesn’t give any difference (the output is from the other channel, or the other speaker doesn’t make any sound.