820-01041 no display no backlight.

yair37

Member
hello, there was very small water damage on the screen side connector, i was clean and all look good but no backlight and display.
i was changed screen and flat cable but the same.
on j8500:
PP5V_S0SW_LCD - 5.1V
PP5V_S0_ALSCAM_F 5.1V
PP3V3_S0SW_LCD 3.3V
PPVOUT_S0_LCDBKLT 0V.
 

2informaticos

Administrator
Staff member
Stable 3V3/5V_S0SW_LCD at J8500 means the LCD is detected; DP_INT_HPD should be high.
Probably image is there, but not easy to detect in the new machines.

If really no image for sure, internal eDP video output could be damaged.
Do you get external video?
USB activity confirmed?
 
Last edited:

yair37

Member
i was change U9850 from oder board...
DP_INT_HP still 0.1v but diode mode on DP_INT_HP (j8500) was 700 and now 1450
 

2informaticos

Administrator
Staff member
Very strange to get steady voltages on LCD connector, without DP_INT_HPD signal.
No reason for PCH to maintain EDP_PANEL_PWR_EN signal, if doesn't recognize LCD (missing DP_INT_HPD).
It can only be tricked by U9801, or more probably U9850.
Check DP_INT_IG/EG_HPD levels.
You may need to change U9850.
 
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