(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)

No

No

No

No

1.check X1, C41, C42

2.check U17,RP25

1.Q2,Q3 ok? (level shift )

2. RP7 ok? ( IIC Pull high)

1.R10,R11ok? ( IIC Pull high)

2.Replace U4

1.check SIL504 1.8V ok?

2.check U2, U3 ok?

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BenQ PE8700 service manual SIL504 trouble shooting U4, U2