Technics RS-M250

TROUBLESHOOTING
Fault
Probable cause
Microcomputer
terminal to
check
Relevant
mechanism
parts
RS-M250
Relevant
external
parts
Mechanism does not
operate at all.
FL not lighting
FL lighting OK.
(MODE LED not lighting.)
MODE indicator lighting
OK.
Microcomputer not
operating
Power not supplied.
Clock not oscillating.
Reset locked.
Microcomputer normal.
(Scan normal)
Connection to FL Driver.
Half SW. closed.
Motor circuit faulty.
39 (VDD)
40 (OSC)
10 to 13
27 (RST)
10 to 13
31 to 37
14 (Ai3)
24, 25
Half SW.
Motor
connection
C310, R347
C309, D317
D311
Q312 to 315
Mechanism defective.
FF/REW
reverse rotation.
FF/REW motor rotating,
reel not rotating.
CAM continuous rotation
in PLAY.
Motor rotating in PLAY,
but CAM’s not switched.
Motor rotates in revese
and does not stop after
switching to PLAY or
PAUSE.
Reverse connection of
motor.
Brake plunger not being
with drawn.
MODE SW. defective.
Trigger plunger not
operating
PLAY or STOP SW,
defective.
24, 25
22 (EQ)
15 (Aiz)
23 (EO1)
16 (Ai1)
17 (Aid)
Motor
connection
Brake plunger
disconnection,
etc.
MODE SW.
Trigger
plunger
STOP PLAY
Leaf SW.
REC IND. due not light up.
(Operation is normal)
PLAY IND. dues not light
up.
PAUSE IND. duse not light
up.
Not counting.
LED or drive transistor
defective.
-do-
-do-
Hall IC faulty, buffer
circuit faulty.
7 (CO6)
8 (CO5)
9 (CO4)
14 (Ai3)
Reel magnet
Q305, R324
Q304, R323
Q303,. R322
1303 (Hall IC)
Q302, D306
AUTO STOP functioning
soon after operation
begins.
No muting.
No peak-resetting.
Accidental erase
prevention mechanims
not functioning.
Operating during EJECT.
Same as the above.
(Not counting)
Muting output connection
etc.
Connection
Leaf SW
Half detection SW.
6 (CO7)
3 (CO10)
15 (Ai2)
14 (Ai3)
Accidental
erasure
Leaf SW
Half detection
SW.
12