YES
YES
YES
Check the I2C communication line. (HDMI Rx/TX)
Check item(8).
Check the I2C communication line :
Check the CPU.
Is the "
I2C
" waveform of the TP HDMI Rx/Tx [
U1027
] correct
(like the one shown in the diagram) when the power is turned
on?
U1027
P_CK 114pin
P_DA 116pin
HDMI Rx/Tx [
U1027
] is
faulty. Replace with a
new device.
HDMI SW [
U1024
] is
faulty. Replace with a
new device.
The CPU [
U1013
] is
faulty. Replace with a
new device.
HDMI Rx/Tx [
U1027
] is faulty.
Replace with a new IC.
Recheck from
check item (1).
If it does not work, replace the PCB.
Check item(9).
Check the I2C commu-
nication line :
Check HDMI Rx/Tx [
U1027
], CPU
[
U1013
] patterns as well as soldering.
If there is no problem, go to the next
step.
Check the HDMI SW.
Remove the damping resistor
[
R1974/R1975
] of [
U1024
].
Is the "
I2C
" waveform correct?
Recheck from
check item (1).
If it does not work, replace the PCB.
Check the HDMI Rx/Tx.
Remove the damping resistor
[
R1537/R1538
] of [
U1027
].
Is the "
I2C
" waveform correct?
NO
NO
YES
YES
NO
*The diagram shows an example.
(Signal patterns vary depending on the tim-
ing.)
Points for checking waveforms
- Crest value (3.3V normally)
- Signal change
- SCL frequency (400kHz normally )
Voltage scale：1.0V/div
Time scale：10us/div
Before Servicing
This Unit
Electrical
Mechanical
Repair Information
Updating
85
