1.3. Power Supply Voltage Abnormalities
1.4. I2C Communication Line Abnormalities
Check the output voltage. POWER PCB to MAIN PCB
[C
N3003 : 1pin
] = +3.3 ± 0.5V, +3.3V_CPU
[C
N3003 : 2pin
] = +3.3 ± 0.5V, +3.3V_D
[C
N3003 : 4, 5pin
] = +5V ± 0.5V, +5V_LEGO
[C
N3003 : 7, 8pin
] = +5 ± 0.5V, +5V_USB
[C
N3003 : 10pin
] = +5 ± 0.5V, +5V_D_A
[C
N3003 : 12pin
] = -5 ± 0.5V, -5V_D_A
Are there large deviations in the output voltage?
The power relay [
RL801
] or relay operation circuit is malfunctioning.
Replace any faulty parts. Or replace the POWER PCB.
Is SMPS [
IC811
] operation stopped while power is being supplied
to the Power PCB unit?
Check the voltage.
The normal value is [
CN3001 : 7, 8pin
]+1V or lower.
Does the power relay operate when the POWER switch is on?
Check conduction in the following area.
RL801
: [3pin] - [4pin]
POWER PCB
Is there an abnormality in any of the power supply ICs?
If the input voltage of all the power supply ICs is 0V, proceed to
"
NO
".
Replace any faulty parts.
Or replace the POWER PCB.
The SMPS circuit is faulty.
Replace any faulty parts.
Or replace the SMPS PCB.
The temperature fuse is blown out in the main transformer, or a
related abnormality has occurred.
Replace the power transformer.
NO
NO
NO
NO
YES
YES
YES
YES
1.4. I2C Communication Line Abnormalities
Check output signal.
MAIN PCB, MCU[
U3001 : 106(SDA), 107(SCL)pin
]
Is there an abnormality in the "
Hi
" (3.3V) or "
Lo
" (0V) level?
Check the communication signal during startup.
MCU [
U3001
:
106(SDA), 107(SCL)pin
] to I2C Device
Is an ACK signal returned from each I2C device?
Check the cable and its connection.
MAIN PCB : [
CN3006
] to AUDIO PCB : [
CN2002
]
NO
Check Soldering or replace for the following parts.
AUDIO PCB [Pull-up :
R2030, R2029
], MCU[
U3001 : 106(SDA), 107(SCL)pin
]
Replace the [
U3001
].
Or replace the AUDIO PCB.
Check that the connection is correct and reconnect FFC.
If conduction does not recover, replace the cable or circuit board.
YES
Check the output voltage.
POWER PCB
[
U1006
] = +5.0V, +5VA
[
U1008
] = +3.3V, +3.3D1
[
U1007
] = +3.3V, +3.3DAC
[
U1009
] = +1.3V, +1V3.DAC
Are there large deviations in the output voltage?
Check each internal connection. If no abnormalities are found, disconnect the AC power supply, allow the internal charge to discharge for around 1 minute and then start the power supply again.
OK
NG
Before Servicing
This Unit
Electrical
Mechanical
Repair Information
Updating
43