TROUBLE SHOOTING
1. POWER
0.6V
1.1. The unit does not power on
YES
YES
NO
YES
NO
YES
NO
NO
Does the power indicator on the front panel flash
in green when the power is turned on?
Is a fuse blown?
Does the power display on the front panel lights
green after approximately 10 seconds?
Check the voltage of [CN712 : 6, 8, 9pin] on the
DIGITAL PCB while the power display is flashing in
green.
Remove the connector [BN502] of the MAIN PCB.
3-4. Protection History Display Mode
The unit does not power on
Is a fuse blown?
Does the power shut down after several
seconds?
Is DC 5 V being supplied from the SMPS PCB
[BN601] to the DIGITAL PCB?
See "
"
Check the circuits around the Microprocessor on
the DIGITAL PCB and replace any faulty parts.
TO "
"
Are there any parts not fully connected into the
connectors that connect the PCBs?
Is DC5V output even when the connector
[CN751] supplying power from the SMPS PCB to
the DIGITAL PCB is removed?
Check the circuits around the Microproces-
sor on the DIGITAL PCB and replace any faulty
parts.
Check for breakages and short circuits in the
circuits and parts between [CN751] on the
DIGITAL PCB and the microprocessor power
supply and replace any faulty parts.
Connect the connectors correctly.
YES
Check for leaks and short circuits
in the parts on the primary side.
Replace any faulty parts.
Blown fuse
Check the rectifier diode in the
rectifier circuit on the secondary
side, and check for short circuits.
Replace any faulty parts.
Replace the fuse after repair.
Check for short circuits between the
regulator output terminal and GND
in the power supply stabilization
circuit. Replace faulty parts if there
is a short circuit.
1.2. Fuse is blown
NO
NO
NO
YES
YES
0V
3.3V
NO
YES
Check the voltage of [CN712 : 7pin] on the
DIGITAL PCB while the power display is flashing
in green.
Before Servicing
This Unit
Electrical
Mechanical
Repair Information
Updating
58
