Philips HTB5150D/12, Service Manual

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5-1 Trouble shooting Chart
VFD No display on Front Control Board
VFD No display on
Front Control Board
Go
Yes
Refer to CN504 on Power Board
No
Fix the connection XP6 on Front
Control Board and XP8 on Main Board
No
Replace MCU U36 on Main Board, or
replace the Main Board
No
Check the XP6 on Front Control Board Pin6,
4, 3 arrive the condition IC U135 PIN2,3,4 No
Yes
Yes
Yes
Correct connection
No
Yes
Replace U135 or VFD
Check every supply voltage on Main Board
whether normal or not.
(XP8, PIN2: -24V, PIN3: 12V, PIN4:3.3V
Check voltage -24V,+12V,3.3V on Power
Board at CN504 position and Front Control
Board at XP6 PIN9:-24V PIN8:+12V,
Check the power key SW1, open/closed key
SW3, source key SW2, stop key S606
on Front Board whether work normally
or not
Check Front Control Board signals at XP6
Pin6 VSCLK, Pin4 VSDA,Pin3 VSTB
Check whether bad solder exists on XP6 on
Front Control Board U135 or VFD
and PIN7:3.3V
Yes