hello everyone,

this laptop came with broken chassis on the left side with ripped off lvds cable, repaired the chassis and replaced lvds cable, now it's turning on but with no display on screen nor vga port..

i don't have a post card, using a USB flash drive with a led indicator shows activity started after 25 seconds from switching on..

all voltages are there:

+3VPCU PL11 = 3.38V
+5VPCU PL8 = 5.09V
+VCORE PL9 & PL10 = 1.05 / 1.18V after 25 seconds
+VGACORE_IGPU PL13 = 1.04v
+1.05V_VTT PL3 = 1.05v
+1.5VSUS PL4 = 1.55v
+1.05V PL14 = 1.04v
+1.8V PQ37 = 1.79v
+0.75V_DDR_VTT = 0.77v
DDR_VTTREF = 0.77v

On CN2 connector (without screen):

pin1&2 +3VLCD_CON = appeared after 25 seconds, 3.33v
pin2&3 EDIDCLK & EDIDDATA = 3.33v with activity after 25 seconds
pin5 +3V = 3.33v
LVDS lines resistance = 126kohm
pin29 +5V = 5.08v
pin36 DPST_PWM = 0v (with and without screen) ?!
pin37 BLON_CON = 3.17v
pin39&40 +VIN_BLIGHT = 19.50v

tried replacing the screen, lvds cable, CPU, RAM... no difference

tried multiple BIOS & EC's with no avail, it's now on a BIOS cut from official website..

measured PCH_DPST_PWM voltage at R267 and it's not there, the resistance can't be measured it's like it's floating/not connected to anything

is it the PCH to blame ?
i've tried to blow on the PCH but still nothing...

can i remove R267 and give a supply +3v to DPST_PWM, from +3VLCD_CON for example ?

why is it taking that long to initialize ?

Check pu18 maybe

pu18 is for DSC only, not installed on UMA boards..

I've removed R267 and injected 3v in DPST_PWM, the screen switched on but still no image..

replaced U15, still nothing..

surprisingly LVDS_VBG = 0v and LVDS_IBG = 0.37v, reflowing the PCH doesn't help

the board gives image through HDMI only, no VGA/LVDS so PCH is my only suspect.. any suggestions ?

this one need pch replacement and i don't have the tools, given without repair..

thank you..