YES
YES
YES
Check the I2C communication line. (HDMI Tx)
Check item(3-1.4.). Check the I2C communication line :
Check the CPU.
Is the "I2C" waveform of the TP near the HDMI SW1 [U1003]
correct (like the one shown in the diagram) when the power is
turned on?
U1003
I2C(HSCL)
I2C(HSDA)
HDMI Tx [U1001] is
faulty.
Replace with a new
device.
HDMI SW1 [U1003] is
faulty.
Replace with a new
device.
HDMI SW2 [U1000] is
faulty.
Replace with a new
device.
The CPU [U1018] is
faulty.
Replace with a new
device.
HDMI Tx [U1001] is faulty.
Replace with a new device.
Recheck from check item (3.1.)
If it does not work, replace the PCB.
Check item(3-1.5.). Check the I2C com-
munication line :
Check HDMI SW [U1000 or U1003],
HDMI Tx [U1001] and CPU [U1018]
patterns as well as soldering.
If there is no problem, go to the next
step.
Check the HDMI SW1.
Remove the damping resistor
[R1169/R1170] of [U1003].
Is the "I2C" waveform correct?
Recheck from check item (3.1.)
If it does not work, replace the PCB.
Check the HDMI SW2.
Remove the damping resistor
[R1061/R1062] of [U1000].
Is the "I2C" waveform correct?
Check the HDMI Tx.
Remove the damping resistor
[R1974/R1975] of [U1000].
Is the "I2C" waveform correct?
NO
NO NO
YES 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
98