LG KG920 - Page 120

4. TROUBLE SHOOTING
- 121 -
Figure 4-81.
CHECKING FLOW
Play MIDI
Check the voltage level
of U200.9 = 2.8V?,
U200.10 = 1.8V?
No
Re-Place
U200
Play MP3
MIDI Trouble
MP3 Trouble
Yes
Check the Signal of
U203.G5 = 26MHz?
No
Re-solder
C209
Yes
Check the Signal,
U203.B5 and U203.A4,
U203.B7, U203.B8.
Yes
No
Re-Place
U203
Check the Level of
U404.C2 = Low ?
No
Re-solder
R429
Check the Signal,
U404.A2 and U404.C2
No
Re-Place
U404
Check the Connection,
CN102(Key)
Yes
No
Re-
Assemble or
Re-place
Speaker
Check the voltage level
of U602.4 = 2.8V?,
No
Re-Place U602
or Re-solder
FB603
Check the solder
condition of R710 ~
R715
No
Re-solder
R710 ~
R715
Yes
Yes
Check the Signal,
U700.11 and U700.12
Yes
No
Re-Place
U700
Check the Level of
U400.A1 = High ?
No
Re-solder
R420
Check the solder
condition of R414, R415,
R417, R418, C410, C411,
C420, C421, L400, L401
No
Re-solder
The
components
Yes
Check the Signal,
U400.A4 and U400.D4
Yes
No
Re-Place
U400
Yes
Check the Level of
U404.C2 = High ?
No
Re-solder
R429
Try again
or Change the Board
Yes
Yes
Check the condition of
Main FPCB.
Replace
Main FPCB
Check the connection
and Solder condition
of CN700 and CN101
Re-solder or
Reassemble
CN700 or CN101
Yes
Yes
No
Yes
No