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 94 (click to view)
3-3. Troubleshooting (BKDS-7015) 3-3-4. Test Procedures
(3) Checking the test result Check the followings on each item of the �AND test�. (a) �1. Fill AND MEMORY with W.� Check that all alphanumeric displays are filled with the letter �W�. (b) �2. Fill AND MEMORY with M.� Check that all alphanumeric displays are filled with the letter �M�. (c) �3. Fill AND MEMORY with BLANK.� Check that all alphanumeric displays light off. (d) �4. Fill AND MEMORY with FULL.� Check that all dots of all alphanumeric displays light up. (e) �5. Lum level = 3� Check that it is possible to adjust the brightness level 3 model (the 1st brightness). (f) �6. Lum level = 2� Check that it is possible to adjust the brightness level 2 model (the 2nd brightness). (g) �7. Lum level = 1� Check that it is possible to adjust the brightness level 1 model (the 2nd darkness). (h) �8. Lum level = 0� Check that it is possible to adjust the brightness level 2 model (the 1st darkness). (4) Ending the �And test� Press your required terminal button to return to the �H/W Tester on CPU-246� menu.