When the results of check item (3-14.1.) are "
NO
"
(Detection of 5V is not OK)
When the results of check item (3-14.2.) are "
00 or 04
"
(Detection of DDC is not OK.)
Check item(3-14.3.).
Check the +5V voltage.
Does the test point near HDMI input terminal [
N2400/N2401/N2402
] indicate 5V?
N2400
HDMI 5
[MEDIA PLAYER]
N2401
HDMI 6
[AUX2]
N2402
HDMI 7
[CD]
5V
5V
5V
Check item(3-14.4.).
Check the DDC line :
Are waveforms of "
DDCCL
" and "
DDCDA
" observed at the test point near the HDMI input terminal
[
N2400/N2401/N2402
]?
N2400
HDMI 5
[MEDIA PLAYER]
N2401
HDMI 6
[AUX2]
N2402
HDMI 7
[CD]
DDCSCK
DDCSDA
Check the +5V voltage. (HDMI IN5 - 7)
Check the DDC line. (HDMI IN5 - 7)
HDMI Switcher1 [
U2401
] is faulty.
Replace with a new device.
Recheck from
check item (3.2.)
If it does not work, replace the PCB.
HDMI Switcher1 [
U2401
] is faulty.
Replace with a new device.
Check for a short circuit in the 5V line and the 5V
Switch IC [
U2400
].
If there is no problem, the HDMI Switcher1
(
U2401
) or the 5V Switch IC [
U2400
] is faulty
Replace with a new device.
Check for a short circuit in the DDC line.
If there is no problem, the HDMI Switcher1
[
U2401
] is faulty.
Replace with a new device.
Recheck from
check item (3.2.)
If it does not work, replace the PCB.
YES
NO
YES
NO
less than 100KHz
5V
5V
This diagram shows an example of the DDC commu-
nication waveform.
-The high level voltage is 5V.
-The frequency of the DDC CLK is 100kHz or less.
Check at each test point.
Voltage scale : 2.0V/div
Time scale : 40us/div
Before Servicing
This Unit
Electrical
Mechanical
Repair Information
Updating
119
