Check item(20).
Check the I2C communication line :
Check the CPU.
Is the "
I2C
" waveform of the TP near the [
U2000
] correct (like the
one shown in the diagram) when the power is turned on?
U2000
R2033 I2C(AVSDA)
R2032 I2C(AVSCL)
Check item(21).
Check the I2C communication line :
Check GUI [
U2800
], VIDEO DECODER [
U2000
] and FET [
Q2001
] patterns as well as soldering.
If there is no problem, go to the next step.
Check the I2C communication line again after replacing the FET [
Q2001
].
If there is still a problem, the GUI [
U2800
] is faulty.
Replace with a new device.
Check the I2C communication line.
GUI [
U2800
] is faulty.
Replace with a new device.
YES
*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
NO
YES
Recheck from
check item (1).
If it does not work, replace the PCB.
Before Servicing
This Unit
Electrical
Mechanical
Repair Information
Updating
104
