HP Probook 4540S No Display

[stingerchamp]

Re: HP Probook 4540S No Display

Hi,

In old boards there used to be separate lvds switch for display

But in new boards lvds connector is directly interact with PCH

Goal :. To convert everything from GPU to pch and cut connection of GPU with PCH

For this every motherboard has nodes alignment specified

For example in this board mention here (schematic ) although if you type Uma in search bar it will pinpoint location need to be changed


Only crt is connected to GPU and lvds is connected to PCH directly and hdmi is also connected to PCH
Also at lvds connector clock and backlight control and data is interlinked with PCH


In this board we just need to change vram id

Vram id or board id

How ?

First step :Replace position of resistor so PCH gets signal that there is no discrete card present

Second step: remove power from GPU via removing coil

Third step : check lvds connector

Make sure clock and data is feeder to pch only

Make sure backlight control and display on is controlled via PCH

Fourth step : hdmi cable connection is directly interacted with PCH not GPU

Then PCH will switch display on lvds from GPU

Rapid change in technology.