The service manual is really great - thanks to it I was able to install the laser unit and thus "save" my CD-player, which seemed to be impossible before I had the manual.
Complete service manual in very good scanning quality with all schematic and PWB graphics as well as assembly & maintenance instructions. A slight drawback is that the rastering of the PWB graphics sometimes makes it a bit difficult to follow fine traces, but no showstopper.
Text excerpt from page 43 (click to view)
TROUBLESHOOTING
2. SYSTEM CIRCUIT
A. LED DISPLAY
No LED display.
Is 5V obtained at IC701 pin # 9, 25? YES
NO Check L703, pin#6 of PJ701
NO Oscillation at IC701 pin #1? Exchange IC701.
YES NO
Is there KEY/SEG signal?
Check PCB
YES NO KEY output at PORT of IC701? Check IC 701 pin #6, 7, 8
YES NO SEG output at PORT of IC701? Check IC 701 pin # 10-12,14,15