But found a strange phenomenon, no matter which connected a/b channel, boot it unless you press one, can not decode the selected way. Feel free to click on the a/b, decode mode can be selected. See circuit diagram, 3817 RL were given due credits should 68/70 feet of various signal outputs, and RL signal is sent to 4588 3817 31/32 output to the foot of 51/52 feet. Output measuring 31/32 feet and 68/70 feet, the road outside mute transistor Q307/Q308, whose base is 3.5 volt, has been working for silent mode, disconnect there is no output. Suspect chip circuit, signal the player after receiving the 68/70 pin, the signal disappears. Try replacing 3817, commissioning normal.XNKservice manual download site