Good scan of the original service manual. All schematics and adjustment procedures are there. It helped me to fix a long lasting problem with the tracking circuitry. The manual also includes the supplementals 1,2 and 3. Included are; electrical schematic's , pcb layout's, mechanical drawing's and exploded views, disassembly manual and maintenance procedures. 236 pages.
Very good manual for Technics SL 303. Manuale molto utile.
Text excerpt from page 2 (click to view)
AVR2105/885 / AVC-1890
SAFETY PRECAUTIONS
The following check should be performed for the continued protection of the customer and service technician.
LEAKAGE CURRENT CHECK
Before returning the unit to the customer, make sure you make either (1) a leakage current check or (2) a line to chassis resistance check. If the leakage current exceeds 0.5 milliamps, or if the resistance from chassis to either side of the power cord is less than 460 kohms, the unit is defective.