Service manual

Buffalo BU1715
38
8.2 Trouble Shooting
8.2.1 Main Board
1.No Screen Appear
Note: 1. If replace “MAIN-BOARD”, Please re-do “DDC-content” programmed & “White-Balance”.
2. If replace “Power Board” only, Please re-do “ White-Balance”
Led Green
Measured CN201 pin5/6 = 12 V?
Measured CN201 pin 9/10= 5V?
Measured U202 pin 2= 3.3V?
Check Correspondent component.
Is there any shortage or cold solder?
Yes. There have OSD show
Yes, all DC level exist
Disconnected the Signal cable (Loose the
Signal cable), Is the screen show “Cable Not
Connected”?
Connected the Signal cable again,
Check LED status.
Replace U601
No, nothing is show
Connected the Signal cable
again
Check Power switch is in Power-on
status, and check if Power switch had
been stuck?
Led Orange
OK, Keyboard no stuck
Led orange
Led Green
Check the Wire-Harness from CN503
Measured RGB (R301, R302, R303) H,
V Input at U401 pin 37,38, was there
have signal?
Check Correspondent
component short/open
(Protection Diode)
NG
OK, Wire tight enough
Check Panel-Power Circuit Block
OK, Panel Power OK
Check U401 Data-output Block
Replace Power board and Check
Inverter control relative circuit
Re-do White balance adjust
OK, input Normal
Measured Crystal X401 (14.318MHz)
OK, clock normal
Replace U401 (TSU16AK)
OK
OK