Harman Kardon HK BDS 270

Trouble shooting Chart
No display on VFD
No display on VFD
Go
Check every supply
voltage on AM board is
normal
Yes
Check+5V,+12V,+5VSTB
voltage on the power and
front board
Refer to Power supply board part
No
Fix the connection XS603 on front board
and CN501 on power board, and 20pin
FFC cable from FB to AM board
No
Replace U721 on AM board, or replace
the AM board
No
Check the U601 pin 31,32,34 arrive the
condition XP808 13,1 0,9
No
Check the pow er key is
working normally
Yes
Yes
Yes
Check the front bo ard
signals VDIN,VCLK,
VSTB
1.Check whether bad
solder exists on pi ns of
VFD,
Correct connection
No
Yes
Replace VFD or FB
harman/kardon
BDS 270 + 570 Service Manual
Page 37 of 90