49
VC-MH705HM/LM
VC-MH815HM/LM,MH85HM
VC-MH715HM,MH835HM
YES
YES
NO
NO
FLOW CHART NO.22 Hi-Fi SOUND MODE TROUBLESHOOTING(2)
NO
YES
Replace IC651.
Is there a REC FM signal outputted
at the IC651 pins(29) to (24) (CH-1)
/pins (21) to (22)(CH-2).
Check PC 5V lines.
Check the AGC setting resistor R678
and pin (39) of IC651.
YES
No HI-FI sound recording(E-E mode is posible).
Check peripheral circuit of IC651 as
shown in table.
L-ch pins (16),(17),(18),(19)
R-ch pins (32),(33),(34),(35)
Check AH-MZ harness.
Check or replace the cylinder.
Is the supply voltage of 5V fed to pin
(25) of IC651?
Is there "L" level at pin (36) of IC651?
NO
NO
YES
NO
FLOW CHART NO.23 Hi-Fi SOUND MODE TROUBLESHOOTING(3)
NO
YES
Replace IC651.
Is there playback envelope signal out
putted at pins(29) to (30) of IC651?
Check PC 5V lines.
Is there A-H.SW.P. signal at
pin (27) of IC651?
YES
No HI-FI sound playback(E-E mode is possible).
Check peripheral circuit of IC651 as
shown in table.
L-ch pins (16),(17),(18),(19)
R-ch pins (32),(33),(34),(35)
Is the supply voltage of 5V fed to pin
(25) of IC651?
NO
Check the A-H.SW.P. line between pin
(27) of IC651 and pin (28) of IC701.
YES
FLOW CHART NO.24 LINEAR SOUND MODE TROUBLESHOOTING(1)
No linear sound recording (E-E mode is possible)
Check the AUDIO MUTE (H) line
between pin (99) of IC201 and pin
(81) of IC701.
YES
YES
YES
YES
YES
NO
NO
NO
NO
NO
Is there signal at pin (4) of IC201?
Replace IC201.
Is the supply voltage of 12V fed to
pin (2) of T601?
Check M 12V line.
Is there signal (Bias) at pin (5) of T601?
Check the Bias oscillation circuit (T601,
Q602,Q603) and A-ERASE CTL line.
Is "L" level applied at pin(99) of
IC201?
Check peripheral circuits of T601.
Check the MH-AA harness and A/C
head.
Is there signal (Bias + Audio sig)
at pin (6) of T601?
www.freeservicemanuals.info
6/17/2019
Digitized in Heiloo the Netherlands
Not for sale!
