Samsung SC-148B Service Manual page 27

No tray open/close
Start
FPC is normally inserted in CN702?
Y
IC301 44pin is 0V at pressing SW702?
Y
IC301 29pin is 0V with tray in?
Y
IC301 28pin is 0V with tray open?
Y
OPEN tary repair
IC301 33pin changes from 1.75V to 5V at pressing SW702?
Y
IC501 14pin chages from 2.4V to 3.9V
and 15pin from 2.4V to 0.7V at pressing SW702?
Y
Output Voltage of IC501 13Pin is impressed into
LOADING (-) and IC501 14Pin(+)?
Y
Replace loading Motor.
N
N
N
N
N
Check R502,R503,R509 soldering.
CheckIC301,33pin, 34pin soldering.
N
Replace IC501
N
Check pattern and soldering
between CN702 and IC501
20
FPC : Flexible Printed Circuit
Retest after inserting FPC in CN702 properly
Check SW702 pattern and soldering
Replace SW702
After FPC short check, no error, check SW soldering of deck
N
CN702 4pin
FPC of CN702 is normally inserted?
becomes 0V?
Retest after inserting FPC in CN702 normally
N
CN702 2pin
After FPC short check, no error, check SW soldering of deck
becomes 0V?
FPC of CN702 is normally inserted?
Retest after inserting FPC in CN702 normally
CLOSE operation repair
IC501 11pin change from 1.75V to +0V at pressing SW702?
IC501 13pin changes from +2.4V to +0.7V, and 15pin
from +2.4V to +3.9V, at pressing SW702?
Y
N
Y
N
Y N
Check R502,R503, soldering.
CheckIC301,33pin, 34pin soldering.
N
Y
Replace IC501