Philips DVP520/00 Service Manual page 15

No display on VFD, and buttons do not work
No display on VFD, and
buttons do not work
Check whether there is
correct
CN303 and CN5
check the -24V
VCC(+5v) voltage on the
power and front board
Check
VSDA0 and VSCK signals
on CN303 on the front board.
1.Check whether bad solder exists on
U301 and pins of VFD,
2.Check whether the circuit connected to
K302, K303, K304 and K301 is broken,
3.Check whether R300, R301 and R302
are open-circuit.
Replace U301 or VFD
Yes
contact between
Yes
F+ F-
Yes
there are VSTB,
Yes
Yes
4-6
No
Fix connection
Fix relative electric circuit in
No
power supply board
No
Check connection between the pin62,
pin63 & pin64 of U3 to CN5
CN5 (PIN 4 V.SCK) CN5 (PIN 3 VSDA0)
No
Fix connection
Trouble shooting chart