Samsung APH289SEF Service Manual page 27

5-3 Troubleshooting by Phenomena
5-3-1 When it is not Power on. (When it is not Displayed.)
1. Causes of Failure
1) Power voltage out of the motion boundary or poor power cord contact.
2) Main PCB fuse cut or poor PCB.
3) Poor panel PCB, poor assembly of tact switch, poor LED display.
2. Inspection Items
1) Power voltage? (AC198V ~ AC264V)
2) Power cord contact?
3) Power fuse(F701) and PCB fuse(F101)?
4) Output voltage of U303(KA7805) (DC4.5V ~ DC5.5V)?
5) Connection harness between Main PCB and panel PCB?
3. Inspection Procedure
Turn power off and on in 5 seconds.
Press OPER key. LED Lights
Power voltage normal (Fuse : AC ↔ AC)?
Check U303 output voltage, 5V?
Check voltage of CN901 #1 ↔ 5 of panel
PCB, 12V? If yes, then Inspect and
exchange panel PCB(Poor panel PCB).
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on and shutter open?
No
AC198V ~ AC264V
Yes
Yes
Yes
Good set operation
Check wire between indoor unit &
No
outdoor unit. Exchange wire.
No
Inspect and exchange Main PCB.
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