HP PL4260N Service Manual page 69

Failure type
Source: HDMI
Description: There is no sound when video/audio signal
input and the volume over the 20 level.
Inspection items
1 Check the connections of speaker cable with terminal
on CB, and ensure the signal is not DVI format and
have audio signal.
2 Check that the volume is over the 20 level.
3 Open the back cover.
4 Check the connections of XP601 on TB and XPC91
on CB.
5 Check the connections of XP003 and check whether
+24V power has been supplied to pins of L600/L601
on TB.
6 Check whether the voltage of R604 on TB is +5V.
7 Check whether there is correct sound signal on pin
#1(HDMI_SD0)/#2(HDMI_SCK)/#3(HDMI_WS)/
#4(HDMI_MCLK) of U85 on MB, and +5V has been
supplied to pin #8 of U85.
8 Check whether there is correct sound signal on pin
#4/#11 /#16/#17 of U67 on MB.
9 Check whether there is correct sound signal on pin
#34(L)/#35®/#20/#21 of NP01 on TB.
10 Check whether there is correct sound signal on pin
#2/#4 of XP601 on TB.
Picture
U67 switches HDMI, PC, COMP1, COMP2 source
audio signal and is controlled by PCA9555BD I/O pins.
U67:74LV4052D for audio
Remarks
HP High-Definition Plasma TV Service Manual PL4260N, PL5060N
U85:CS4334 for HDMI audio D/A
63