Troubleshooting Charts - Harman Kardon BDP 20/230 Service Manual

harman/kardon
No display on VFD, and buttons do not work
No disp lay on VF D, and
buttons do not work
Check ever
voltage on main board is
normal
1.Check whether bad so lder exists
on U721 and pins of VFD,
2.Check w
connected to K7, K2, K3, K4, K5,
K6 is broken.
Yes
y suppl y
Yes
Check38V,5V,+12V
voltage on th e po wer
and front board
Yes
Check th e front bo ard
signal VDIN,VCLK,
VSTB，
Yes
hether the circuit
Yes
Replace U721
5-1
No
Refer to Power supply board part
No
Fix the c onnection XS603 on front
board and ZD602
No
Check the U721's pin 61,60,59singal
No
Correct connection
BDT 2 / BDT 20 Service Manual
Trouble shooting chart
Page 9 of 37