MSI GF63 MS-16R61 - Brak obrazu na LCD, HDMI działa

Witam,

Laptop MSI GF63 płyta główna: MS-16R61 - objaw: nie wyświetla obrazu na LCD, na zewnętrznym po HDMI obraz działa prawidłowo. Trafił do mnie po zalaniu, na płycie nie było śladów zalania - klawiatura musiała wszystko zatrzymać albo nie było dużej ilości cieczy.

Sprawdziłem złącze EDP 40 pin, najważniejsze pomiary z tego złącza, chyba że coś przeoczyłem.

3pin = 012V,
5pin = 1.75V,
6 pin = 5V,
7 PIN = 3.3V
32 PIN = 2.2V
33 - 36 PIN = 3.3V
38 - 40PIN - 19V

Pomiar układu PU21 MP2143 przełącznika 3.3V:

1 - 5V
2 - 5V
3 - 3.3V
4 - 0V
5 - 3.3V
6 - 0V
7 - 0.6V
8 - 3.3

Podmieniłem również na inną matrycę LCD - brak obrazu a nawet podświetlenia, co prawda nie miałem wersji 144hz ale FHD ze złączem edp 40PIN.
Nie mogę namierzyć schematu do tego modelu.

Co mogę jeszcze sprawdzić, zmierzyć w tym modelu ?
Będę wdzięczny za wskazówki.

Hello!

- Set your multimeter to the diode test mode and measure the voltage drops to ground on pins 3, 4, 8, 9, 11, 14, 15, 32 of LVDS connector EDP1 with the positive (red) probe connected to ground. Measure with the internal matrix disconnected from the board.

Perform the following measurements, when the machine is turned on with the external monitor disconnected from the board:
- Measure the voltage to ground on pin 32 of LVDS connector EDP1 with the internal matrix connected and disconnected from the board.
- Measure the voltages to ground on pins 14, 15 of LVDS connector EDP1 with the internal matrix connected to the board.

internal matrix disconnected:

EDP PIN voltage drops:
3 - 0,44V
4 - 0V
8 - 0.75V
9 - 0V
11 - 0V
14 - 0V
15 - 0V
32 - 0.42V

matrix connected and disconnected PIN 32 = 0V
matrix connected PIN 14-15 = 0V

I understand that the edp_hdp PIN32 EDP LVDS signal comes from the PCH bridge?

Measure the resistances to ground on pins 3, 4, 8, 9, 11, 14, 15, 32 of LVDS connector EDP1 with the internal matrix disconnected from the board.

matic wrote:Measure the resistances to ground on pins 3, 4, 8, 9, 11, 14, 15, 32 of LVDS connector EDP1 with the internal matrix disconnected from the board.

EDP connector:

PIN3 = 7.6kΩ
PIN4 = 7.6kΩ
PIN8 = 40kΩ
PIN9 = 40kΩ
PIN11= 0.66MΩ
PIN14 = 49.2kΩ
PIN15 = 0.586MΩ
PIN32 = 26.4kΩ

on Pin 32 3.3V appears for a moment and then drops to 0V. with or without the matrix connected.

Please specify the model of the original matrix and the replacement one you tested with.

Oryginal LCD: B156HAN15.1
Test LCD: B156HAN08.4

If you have an option, test the original matrix on any other laptop.

I had no way to test the matrix on another laptop, I ordered a new original one for MSI. The effect is the same, no image. The voltage +3V_LCD appears for a moment and drops to 0V

Something strange is going on with your measurements. You have measured voltage drops to ground of 0V (indicating a short circuit) on some pins of the LVDS connector, but at the same time the resistances on these pins are high:

martiv wrote:EDP PIN voltage drops:
4 - 0V
9 - 0V
11 - 0V
14 - 0V
15 - 0V

martiv wrote:EDP connector:
PIN4 = 7.6kΩ
PIN9 = 40kΩ
PIN11= 0.66MΩ
PIN14 = 49.2kΩ
PIN15 = 0.586MΩ

I don't know how it happened, why did I enter it like that? - I presentthe measurement of the drops on the EDP connector

4 - 0.77V - PDM_CLK_CONN
11 - 0V (empty pin in the diagram )
14 - 0.85V (EDP_BKLTCTL)
15 - 1..4V (BL_ON)

I replaced the PU21 chip and as a precaution I did a PCH reflow - No voltage BL_ON

martiv wrote:11 - 0V (empty pin in the diagram )

According to the BoardView I have, this pin is not empty:

Moreover, if this pin were not used, the voltage drop reading must be OL (Over Load or Out of Range), and not 0V.

the signal is from the KBC kb9548qf2 BGA chip, shouldn't it be 3V?