I found the manual to be clear concise and complete. It was of immense assistance when removing the unit as the unit was over 22 years old and the wiring diagram was unobtainable from the manufacturer. The exploded drawings were clear as were the instructions and labels.
This manual was very good & was very helpful with repairs.
Always great & fast service from Owner's manual.
Text excerpt from page 4 (click to view)
Precaution to replace Optical block (KSM-213RSCM) (KSS-213R)
Body or clothes electrostatic potential could ruin laser diode in the optical block. Be sure ground body and workbench, and use care the clothes do not touch the diode. 1) After the connection, remove solder shown in the right figure.