Sankyo STD-1700 - Electrical Parts Troubleshooting

8.2
Electrical parts
1. No playback sound.
1-1.
Touching the head terminals produces-sound.
Head out of alignment.
Head terminals incorrectly soldered.
Recording sound can be heard (LINE IN input)
Q501, 502 defective.
R110/210 contact failure.
Sound heard from headphones, but no sound at
LINE OUT.
LINE OUT terminals defective.
Sound at LINE OUT terminals, but no sound
from headphones.
Headphones jack defective.
Headphones jack disconnected or lead wires
broken.
During
playback,
sound
at
pins
3
and
5
of
the
DIN
jack,
but
no
sound
from
LINE
OUT
terminals
and
headphones.
Q103/203, 0104/204 defective.
No sound.
S5-1/5-2 contact failure.
Lead wires to S5-1/5-2 broken or disconnected.
Dolby-NR_ IC (NE545B) defective.
Q103/203, 0104/204 defective.
Only noise is produced.
Open in the Dolby circuit board.
Lead wires of OUTPUT VOLUME broken
(only STD-1800). .
Lead wires of OUTPUT VOLUME defective
(only STD-1800).
2 Recording impossible.
2-1,
°
e
e
2-2.
2-3.
yg
P~eee
Erasure impossible.
Bias oscillator inoperative.
Erase head out of alignment.
Lead wires of erase head broken or disconnected.
Erasure possible.
Q101/201, Q102/202 defective.
R143/243 contact failure.
Lead wires to LINE IN terminals broken.
LINE IN terminals defective.
Lead wires to R111/211 broken.
Recording impossible from MIC jacks.
MIC jacks defective.
Lead wires to MIC jacks broken.
LINE IN terminals defective.
Recording impossible from DIN jack.
Lead wires to DIN jack broken.
DIN jack defective.
MIC jacks defective.
Lead wires to MIC jacks broken.
LINE IN terminals defective.
3. Playback sound weak.
3-1. Abnormal signal noise ratio.
@ Dirty head.
3-2. Both sound and signal are weak.
@ R110/210 improperly adjusted.
@ R139/239 defective, lead wires broken
(only STD-1800).
@ Q1 defective.
@ D7 defective.
4. Meter lamp does not light.
@ Lamp burnt out.
@ Lead wires to lamp broken or disconnected.
5. Recording indicator does not light.
@ D1 defective.
@ Lead wires to D1 broken or disconnected.
6. Dolby indicator does not light (only STD-1800).
@ D2 defective.
@ Lead wires to D2 broken or disconnected.
7. Abnormal signal noise ratio.
@ (Q1 defective.
8. No power.
@ Power switch defective.
@ Blown fuse.
@ Q1, D3-D6, D7 defective.
17
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