Envision EN9110, Service Manual

Page: 21 / 58

20
II (a) the screen is abnormal, stuck at white screen, OSD window can’t appear,
but keyboard & LED is normal operation.
At general, this symptom is cause by missing panel data or panel power, so we must
check our wire-harness, which connected to panel or the panel power controller (U203)
Check if the Wire harness from CN201 loose?
Check the wire on both Panel-side and Main board side.
Check the Panel-Power circuit as above (page 20)
U203 pin 5,6,7,8, must be 5V
Yes, tight enough
Yes, Voltage normal
Check the LVDS-Power L904= 3.3V?
Check both U201 & U202 LVDS-Input pin 31= 45mhz
–
65mhz, and pin 28 = Vsyn freq, pin 27 = 45khz- 65 kHz
Yes, Voltage normal
Yes, Frequency normal
Replace both LVDS chip (U601 & U602)
Tighten it.
NG
Check U903, which convert the 5V to
3.3V
Check U600 DATA-OUPUT block as
above (page 20)
NG
Check OSCILLATOR Block as
above (page 20)
NG, no data output
Replace U502 MCU and check it RESET
pin 10, must be turn high to low when first
AC power-on
OK, all clock is normal
Replace U600 GM5020
OK, reset is normal
Check U600 DATA-OUTPUT block again
NG, still no data out
NG