Harman Kardon BDP 20/230, Руководство по обслуживанию

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No display on VFD, and buttons do not work
No
No
No
Yes
Yes
No disp lay on VF D, and
buttons do not work
Check ever y suppl y
voltage on main board is
normal
Refer to Power supply board part
Check the U
721
’s pin
61
,
60
,
59
singal
Correct connection
Replace
U721
Yes
Yes
Yes
No
Check
3
8V,5V,+12V
voltage on th e po wer
and front board
Check th e front bo ard
signal VDIN,VCLK,
VSTB
，
1.Check whether bad solder exists
on U
721
and pins of VFD,
2.Check w hether the circuit
connected to K7, K2, K3, K4, K5,
K6 is broken.
Fix the c onnection
XS603
on front
board and
ZD602
Trouble shooting chart
5-1
harman/kardon BDT 2 / BDT 20 Service Manual
Page 9 of 37