Haier HL42B-B, Service Manual

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First
，
check cables which connect with PSU
，
then check as follows
1) Check input voltage as NO picture
2) Check speaker output
First, check speaker anode (+) and cathode (-),confirm speaker short or not. If short , replace speaker.
Second, check CN2, CN3 with oscillograph, confirm wave output or not.
Connector: CN2, CN3
10.2 PSU failure check
State: No power
First, check cables which connect with PSU, then check as follows
1) Check PSU input voltage
（
AC input
）
voltage :
～
120V
connector:CON1
（
P1,P5
）
2
）
Check PSU output voltage orderly
：
voltage :+5V(Stand-By) → ON
（
5.0V
）
→ +24V ,+12V
connector:CON4
（
3
）
→ CON4
（
1
）
→ CON4
（
6,7
）
,CON2
（
1-4
）
State
：
No sound