Samsung SC148BE Troubleshooting
18
Troubleshooting
+5V, +12V of CN701 is normally inputted
after connection of power cable?
X201, X301, X401 oscillate ?
Check power short and power supply cable
connection state
①
IC201 75pin, IC301 12pin, 54pin IC401 87pin for power input
➁
Check C303, C304, C207, C208, R210, C402, C401soldering
➂
If normal replace X201, X301, X401
IC301 19pin change from 0V to 5V ?
Inputted Voltage of IC301 5pin is 1.5V~2.0V ?
Check R401, R402, R333 Rsoldering
Y
Y
N
N
N
N
N
Input / output IC301 57pi n~80pin,
1pin~4pin
pulse waveform ?
Check IC301 pin soldering
Y
Y
Y
N
In case FLASH ROM Memory of IC301 16pin
0V, and Rom memory inputted 5V ?
Check R320, R321 soldering
Check R301, R302 soldering
Equipments required at repair
1. Oscilloscope(100MHz or more ) 2. PROBE for Oscilloscope(10:1)
3. PC(486 ormore)
Verify the circuit of power unit and the first status(Plug-in the power cable without I/F cable and verify.)
A
19
N
N
N
N
N
Disk insert
Tray in / out ? Refer to Tray open / close
Y
Y
Laser diode on ? Refer to No laser diode on
Y
Laser diode on ? Refer to No focus lock
Y
Focuse up / down ?
Y
Disc rotates ? Refer to No disc rotation
Y
Pause state
❋ Pause state : LED off as disc rotation state and continue 1 track jump
Y
Spindle lock ?
Y
Input Voltage of IC201 9pin, 21pin 3.6V ?
Pick up moves in at power on after moving
out ?
Check after SET assembly
1TRACK JUMP TE
A
20
No tray open/close
FPC is normally inserted in CN702? Retest after inserting FPC in CN702 properly
Start
N
Check SW702 pattern and soldering
❋ FPC : Flexible Printed Circuit
Replace SW702
After FPC short check, no error, check SW soldering of deck
FPC of CN702 is normally inserted?
Retest after inserting FPC in CN702 normally
After FPC short check, no error, check SW soldering of deck
FPC of CN702 is normally inserted?
Retest after inserting FPC in CN702 normally
N
N
N
IC301 44pin is 0V at pressing SW702?
Y
IC301 29pin is 0V with tray in?
CN702 4pin
becomes 0V?
CN702 2pin
becomes 0V?
N
N
N
N
IC301 28pin is 0V with tray open?
Check R502,R503,R509 soldering.
CheckIC301,33pin, 34pin soldering.
Check R502,R503, soldering.
CheckIC301,33pin, 34pin soldering.
Replace IC501Replace IC501
Y
Y
Y
Y
IC501 11pin change from 1.75V to +0V at pressing SW702?
N
N N
N
N
IC301 33pin changes from 1.75V to 5V at pressing SW702?
IC501 13pin changes from +2.4V to +0.7V, and 15pin
from +2.4V to +3.9V, at pressing SW702?
IC501 14pin chages from 2.4V to 3.9V
and 15pin from 2.4V to 0.7V at pressing SW702?
Output Voltage of IC501 13Pin is impressed into
LOADING (-) and IC501 14Pin(+)?
Check pattern and soldering
between CN702 and IC501
Replace loading Motor.
Y
YY
YY
Y
OPEN tary repair
CLOSE operation repair
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