5-2 Trouble shooting Chart
No display on VFD
No display on VFD
Go
Check every supply
voltage on Main board is
normal
Yes
Check+5V,+12V,VCC_D
voltage on the power and
Main board and 38V on
FB Board
Refer to Power supply board part
No
Fix the connection XP4 on Main board
and CON503 on power board, and
24pin FFC cable from FB to Main board
No
Check the U701 pin 31,32,34 arrive the
condition XP504 13,12,11
No
Yes
Yes
Check the front board
signals VDIN,VCLK,
VSTB
1.Check whether bad
solder exists on pins of
VFD,
Correct connection
No
Yes
Replace VFD or FB
