820-3115 not booting

arnonabuurs

New member
Hi Guys, I have a liquid damaged board in front of me. The damage seems very local. Attached pic 1 showing the affected IC (after ultrasonic!). We have replaced them. The board has an orange light fan is spinning happily. I did some test on the replaced IC, C3990 has 3.3v now. Then on the replaced Q9706 I have 12.55v on pin 4 and 12.22v on pin 3. I testedall small r as in the attached pic 2 and the lines they seem fine. I wanted to test LCD_BKLT_EN but cannot find where it is coming from in the schematics and also wander what its voltage should be. Any suggestions?

Right now the system is running but no chime, I guess cause the backlight enable signla doesnt come through.
 

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aprendiz

Moderator
If not chime, do not expect image shows up.....
Does it beeps without memory??
CPU Vcore present???
Mouse light up???

LCD_BKLT_EN cames from PCH with the name of LVDS_IG_BKLT_ON, but PCH needs to be running ok first!!
 
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