Philips DVR7100/75 Service Manual page 17

7. Lock Signal Fail : Flow chart
Lock Signal Fail
Check cable input
has right signal
Check U32 pin4.6.11.12
Have correct voltage
Replace Check U32 pin15.23.28
No
U32 Have correct voltage
Send back tozinwell
Yes
No
Chack the signal source
Yes
No
Check J21 pin14 voltage
is correct or not
Yes
Check U31 pin2(5v)
voltage is correct or not
Yes
Check U29 pin2(1.8v)
voltage is correct or not
Check U28 pin2(3.3v)
voltage is correct or not
Send back to zinwell
17
Send back to
No
zinwell
Yes
Check U31 pin2(5v)
No
voltage is correct or not
Yes
Replace U11
No
Check U29 pin2(1.8v)
voltage is correct or not
Yes
Replace U11
No
Check U28 pin2(3.3v)
voltage is correct or not
Yes
Replace U11
Send back
No
To zinwell
Yes
No
Send back
to zinwell
Yes
No
Send back
to zinwell
Yes