HBD-N590/N790W/N890W/N990W/N995W/T79
2
TROUBLESHOOTING
1. Power check
fl
ow
The power is turned on.
Check that a sound is
outputted normally.
Check that [Audio Settings] -
[Audio output] in the menu
screen is “Speaker”.
Check that the output voltages of the
SWITCHING REGULATOR are the following
value.
CN301 pin 1: 12 V (A+12V)
CN301 pin 2: 12 V (UNSW12V)
CN301 pin 3: 12 V (FEUNSW12V)
CN301 pin 8: 6 V (UNSW6V)
Check that the following fuses are not damaged.
F5303/F5305/F5306/F5307/F1301/F501
Check the following power control signal in the
power on state. (Normally voltage: +3.3 V)
MB-149 board
IC6301 pin 36 to 38 (PCONT1 to PCONT3)
NG
OK
OK
OK
Check the related IC on the MB-149 board.
OK
OK
Check each voltage with reference to the
schematic diagrams, and check that there is
no problem in them.
OK
Check that a picture is outputted normally.
NG
Optimize the speaker settings.
NG
Check that the drive is
operating normally.
– Continued on next page –
OK
Refer to the “2-1. Flow of drive section check”
on page 6 on original service manual.
NG
OK
Check that harness is
inserted normally.
When harness is inserted
normally, exchange the
SWITCHING REGULATOR.
Exchange the damaged fuse.
Exchange the complete
MB-149 board, when the
power is not turned on,
even if you exchange fuses.
NG
NG
Power supply IC is damaged.
Exchange the power supply IC.
NG
Refer to the “2. Video check flow” on
page 4.
NG
Exchange the IC6301.
Part No.
Description
A-1857-997-A IC R5F3650KCDFB
(for
SERVICE)
NG
