820-00840 no image

Hi , ive got an 820-00840 which had a liquid spill , U7420 was shorted to ground , replaced U7420 and laptop switching on but no display , i did get a display once but when i turnt it off it didnt come back again . I have 3.3v on PP3V_S5_LCD @ U8501 , PP3V3_SOSW_LCD_R is missing, LCD_PWR_SLEW_3V3 is also missing, PANEL_P3V3_EN is also missing but im struggling to see where this rail is created in diode mode this rail reads .546 so it shouldnt be shorted, any pointers in the right direction would be great


Staff member
Resolder all components in liquid affected area.
Heat CPU with quality flux; there may be accumulated crap underneath.
little update , i did reflow all the components and flux the cpu and put it through the ultra sonic again which made no difference however ive just realised the board turns on everytime if i leave it disconnected until it goes stone cold