This manual is accurate and of high quality. It is only volume 2 of the service manual. This is schematic, parts lists, and exploded mechanical drawings. The theory of operation and the diss-assembly instructions are in volume 1. The unit can be tricky to dis-assemble portions of so the volume 1 manual can be important. The product description of the manual is accurate but it does not say anything about volume 1 and the image of the front page does clearly say Volume 2.
It has all the information you will need to fix it. The main circuit diagram is only A4 but being a PDF, you can print it to any size - I did it on two sheets of A3 and it didnt lose any detail - just made it readable when pinned up above the bench. I've found the fault, just need to buy some obscure bits to get it going again!
I cant fault the process, I paid for the manual in the morning and it was ready to download by lunch time.
Very good copy in a 54 pages PDF archive. This is my sixth purchase here. :)
Text excerpt from page 8 (click to view)
Filter Block Since the sound signal from the CPU is a stepped waveform, the filter block is added to smooth the waveform.
CPU MSM6567-15
To mute circuit
Mute Circuit The mute circuit removes noise from the sound signal just before the signal fades away. The circuit detects amplitude of the decaying sound signal by amplifing it by 1000 times, and transistor T6 flows the signal into the ground when the amplitude decays almost zero. +0.5V at the minimum amplitude (no sound) -2.7V at the maximum amplitude Sound signal from filter block