4-4
Disc cannot be read
.
No
Yes
No
Yes
No
Yes
Yes
No
No
Yes
Disc cannot be read.
Check the loaded circuit
1.Check voltage on pin 100 of U1 varies
between 0 and 3.3V:
Æ
3.3V for CD
Æ
0V for DVD
2.Check whether peripheral components
are eroded or defect
Check the FFC connection
between 24P and the loader.
Check U1 and peripheral components
Re-solder or replace the defective parts
Check the connection
between U1
Correct connection
Replace U1 or loader.
Yes
Check whether there is
laser voltage (2.3V for DVD
and 1.9V for CD) on
Collector of Q2 &Q3
Check if there is RFO signal on
pin10 of CN2. (The normal
RFO signal is a clear
reticulated wave)
Check U1, U7, and peripheral
components are eroded or
badly soldered.
Trouble shooting chart