[SOLVED]820-3476-A Chimes but no Image

[BCConnection]

This one is odd
Computer chimes, backlight turns on after a few seconds then keyboard backlight turns on.
Screen is blank.
New screen same results.


LCD SW is 5v
BL is 32v
EDP,SMBUS,I2C BKL all are 3.3v
LCD_HDP_CONN is 2.6v

Data lines all are OL in Diode mode.

No display on external monitor either.
SMC Reset no change
PRAM Reset no change
SMC Bypass no change


Happened after customer disconnected Thunderbolt monitor and HDMI monitor from the laptop and went home.

 

[BCConnection]

Data lines for LCD all read 0.9 Mohms

 

[BCConnection]

no BL with SSD removed

 

[dukefawks]

Data lines to LCD have caps in the line so measuring there will only show the 1M termination resistor. Measure diode mode before the cap and check continuity from caps to LCD connector.
You did test with a 2013/14 assembly?

 

[BCConnection]

Yes and I found out the issue. LVDS Connector looked perfect but something was messed up with it. I read an older post you had suggested LVDS even though they had 49v on backlight where in my case the backlight was working but no image. I guess they damaged something on the LVDS even though under the scope I cannot see anything inside or on the pins that would cause it.

Thank you Duke from the past and Duke of now

 

[BCConnection]

Diode readings were fine for the lines but only thing i can think is the connector was screwing with a data line?

 

[smiba]

Sometimes the pins of the connector inside (very hard to see) are messy, corroded or bent. I've had bad LVDS connectors do weird stuff before even through they looked pristine.