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.
Text excerpt from page 12 (click to view)
6. PRECAUTIONS FOR REPAIR: MODULE QW-1569/1578 6-1. AC (ALL CLEAR)
1. Perform AC (ALL CLEAR) when inserting a new battery, or else the memories and/ or counters may give erratic displays. Touch the AC contact and the positive (+) side of the battery or main plate with the metallic tweezers. The contact should be made for about two seconds. 2. On removing of the module from the case, please insert the precision screw driver between the module and the case pointed by an arrow. QW-1569