820-00923 No image

[No-Clean]

Clean board no water damage and no more history, I have image on external screen.

EDP_PANEL_PWR_EN and PP3V3_S0SW_LCD and PANEL_P5V_EN and PANEL_P3V3_EN come on for about 1 second then leave
All tests are done with good LCD connected and new LCD flex.

 

[2informaticos]

DP_INT_HPD pulses at least?

 

[No-Clean]

Yes DP_INT_HPD pulses same as the other ones mentioned before.

 

[2informaticos]

Did you test with another LCD assembly?

 

[No-Clean]

Yes, 2 known good ones.

 

[2informaticos]

5V_S0SW_LCD also tries to appear?

 

[No-Clean]

Yes, pulses once same as the other ones mentioned before.

 

[2informaticos]

Seems to be a problem with CPU eDP video output.
It should detect LCD presence and maintain the voltages, once DP_INT_HPD goes high.

 

[No-Clean]

 

[No-Clean]

Thanks either way.

 

[piernov]

Can check diode mode to ground on EDP_INT_AUX_N and EDP_INT_AUX_P to see if the transceiver inside the CPU is completely dead at least.

 

[No-Clean]

Thanks @piernov EDP_INT_AUX_N is OL and EDP_INT_AUX_P is 0.211 measured in diode mode, I dont have another board to compare, any input will be greatly appreciated.

 

[2informaticos]

You must get almost same value on both lines; red probe connected to ground.
The CPU eDP output is damaged...

 

[No-Clean]

Thanks, that is what I figured, yes red probe on gnd.

Thanks again for all the help.