YES
YES
YES
YES
Checking the reset waveform. (HDMI Switcher1)
Check the I2C communication line. (HDMI Switcher1)
Check item(10). Checking the reset waveform :
Check the waveform.
Is the "RESET" waveform of the TP near the HDMI Switcher1
(U1003) correct (like the one shown in the diagram) when the
power is turned on?
U1003
RESET
Check item(11). Check the I2C communication line :
Check the CPU.
Is the "P_DA, P_CK" waveform of the TP near the HDMI Switch-
er1 (U1003) correct (like the one shown in the diagram) when
the power is turned on?
U1003
P_CK
P_DA
Check the reset circuit between
CPU (U1018) and HDMI Switcher1
(U1003).
If there is no problem, the HDMI
Switcher1 (U1003) is faulty.
Replace with a new device.
Recheck from check item (3).
If it does not work, replace the
PCB.
HDMI Switcher1
(U1003) is faulty.
Replace with a new
device.
HDMI Switcher2
(U1000) is faulty.
Replace with a new
device.
HDMI Tx (U1001) is
faulty.
Replace with a new
device.
The CPU (U1018) is
faulty.
Replace with a new
device.
HDMI Switcher1 (U1003) is faulty.
Replace with a new device.
Recheck from check item (3).
If it does not work, replace the PCB.
Check item(12). Check the I2C com-
munication line :
Check HDMI Switcher1, 2 (U1003 or
U1000), HDMI Tx (U1001) and CPU
(U1018) patterns as well as soldering.
If there is no problem, go to the next
step.
Check the HDMI Switcher2
Remove the damping resistor
(R1061/R1062) of (U1000).
Is the "I2C" waveform correct?
Recheck from check item (3).
If it does not work, replace the PCB.
Check the HDMI Tx.
Remove the damping resistor
(R1974/R1975) of (U1000).
Is the "I2C" waveform correct?
Check the HDMI Switcher1
Remove the damping resistor
R1170/R1169 of U1003.
Is the "I2C" waveform correct?
NO
NO
NO NO
YES YES YES NO
Examples of conrmation waveform
*The diagram shows an example.
(Signal patterns vary depending on the
timing.)
Points for checking waveforms
- Crest value (3.3V normally)
- Signal change
- SCL frequency (400 kHz normally )
87
Caution in
servicing
Electrical Mechanical Repair Information Updating