Philips MDV434/55/77 Service Manual page 15

Only DVD disc or only disc except DVD can be played
Only DVD disc, or only disc
except DVD can be Played.
Go
Check the
connection between
24pin and the loader.
Yes
Check laser voltage (2V) output
on Collector of Q8, if pin 22 of U3
is at low level.
Yes
Check whether there
is voltage variance on
pin 22 of U3.
Yes
Check whether pin 1 to pin38
of U3 and
components are
soldered, defected
Yes
Check Q5, Q6, Q8
whether in
condition
Yes
Change U3 or the loader.
FFC
No
No
No
No
peripheral
badly
No
good
4-5
Check the loaded circuit
Check the solder status on U3 and
peripheral components
check if bad solder exist on U3 and
peripheral components
Replace the bad spare parts
Correct connection
Trouble shooting chart