Service Note - Sony M-98V Service Manual

This set uses the photo reflector PH701 to detect the rotation of the gear. PH701 is on the main board and so removal of the main board does
not allow the set to detect the rotation of the gear. This makes motor control impossible which prevents normal operation.
When repairing the set as energized with the main board removed, proceed as follows:
• Service the Main Board
1. Short the BP701 (SERVICE) on the main board. (see the Fig. 1.)
2. Refer to the "SECTION3 DISASSEMBLY" (page 5) and open the main board.
3. Put a tape in the set.
4. Fixed at S703 (TAPE DET) on mode or connect the jumper wire between TP38 and GND (TP66).
5. Supply 3 V DC to the battery terminals.
6. Rotate the S701 (MODE SELECT) one turn by hand (mode sensor).
7. Press the desired operating switch (9 (, FF, etc.).
8. Check the mode on the liquid crystal panel. Use item 6 repeatedly to switch modes.
9. When finished with the job, disconnect the power and open (remove the short) the BP701 (SERVICE).
SECTION 1

SERVICE NOTE

– MAIN BOARD (SIDE B) –
S701
(TAPE DET)
(MODE SELECT)
BP701
(SERVICE)
TP38
S703
TP66
SHORT
' terminal ' terminal
Fig. 1.
– 3 –