Technics SL-1500C Owner's Manual page 40

No sound from LINE OUT Terminal
(Large humming noise)
(from the previous section)
Is the correct voltage
presented at following points?
Normal:
CK2021-CK2022(GND) : +11.5 to +12.5V
CK2023-CK2022(GND) : -11.5 to -12.5V
YES
Is the FFC between
P1002 on MAIN PCB and
P4002 on PHONO OUT PCB
inserted correctly?
YES
What voltage between
CKB2 and CKB4 (GND)?
0V
(LINE)
What voltage between
CKB3 and CKB4 (GND)?
0V
(MUTE OFF)
Replace PHONO OUT PCB.
CK2023:-12V
NO
Disconect Connector P2102.
Is the correct voltage presented at following points?
CK2021-CK2022(GND) : +11.5 to +12.5V
CK2023-CK2022(GND) : -11.5 to -12.5V
NO
Insert correctly.
＋5V (PHONO)
Replace PHONO OUT PCB.
＋5V (MUTE ON)
Replace MAIN PCB.
14
CK2021:+12V
CK2022:GND
MAIN PCB
Normal:
YES
Replace PHONO OUT PCB.
P1002
CKB4
(GND) CKB2
Connector
P2102
NO
Replace MAIN PCB.
P4002
MAIN PCB
CKB3
(PHONO_EQ_MUTE)
(PHONO_H_LINE_L)