BenQ PE8700 Service Manual page 42

(2) SIL504 trouble shooting: (U4, U2)
X1, 20Mhz?
RESET
successful?
YES
System IIC ok?
(U4 pin 15,14)
YES
SIL504 IIC ok?
(U4 pin 2, 3)
YES
DEINTDONE
Signal ok? (U4
pin21)
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1. check X1, C41, C42
2.
check U17,RP25
No
1.Q2,Q3 ok? (level shift )
2. RP7 ok? ( IIC Pull high)
No
1. R10,R11ok? ( IIC Pull
high)
No
2. Replace U4
1. check SIL504 1.8V ok?
2. check U2, U3 ok?
No
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