TMDS Signal
3.3V
TMDS
Example of waveform in check ① Example of waveform in check ②
Voltage scale：1.0V/div Voltage scale：1.0V/div
Time scale：20ms/div Time scale：1s/div
When the results of check item (30) are "
22
"
(Detection of DDC is OK.)
Check item(33).
Checking register of the TMDS CLK detection status
register :
Send the following command from Termite.exe.
HDMI Rx/Tx
Send the command "
i 0006 00FF 0001
".
When the following value is returned, go to Yes.
HDMI In4 "
22
" HDMI In5 "
11
"
When the following value is returned, go to No.
HDMI In4 "
20
" HDMI In5 "
10
"
Check item(35).
Checking the audio signal output :
Check the audio signal waveform at the following test point.
Is the waveform like the sample?
129/131/132/133/134/135/136pin
U1027
Check item (34).
Checking the TMDS input waveform. :
Check the TMDS waveform at the following test point.
Is the waveform like the sample?
HDMI In4
80/81/83/84/86/87/89/90pin
HDMI In5
93/94/96/97/99/100/102/103pin
U1027
Checking the TMDS status register.
Example
i 0006 00FF 0001
Check for a short circuit in the pattern of the
TMDS line of the HDMI Rx/Tx [
U1027
] from the
HDMI input terminal.
If there is no problem, the HDMI Rx/Tx [
U1027
] is
faulty. Replace with a new device.
HDMI Rx/Tx[
U1027
] is faulty.
Replace with a new device.
Recheck from
check item (2).
If it does not work, replace the PCB.
The digital audio block is faulty.
Check the digital audio device.
Check "
AUDIO" in troubleshooting.
If it does not work, replace the PCB.
HDMI Rx/Tx[
U1027
] is faulty.
Replace with a new device.
YES
YES
NO
NO
NO
YES
3.3V
The diagram shows an example of the wave-
form of pin 129. (I2S0 Data)
Waveform check points
- Crest value (3.3 V normally)
- Signal change
Check the waveform of each pin.
Voltage scale：1.0V/div
Time scale：20ms/div
93
Caution in
servicing
Electrical
Mechanical
Repair Information
Updating
