820-00239-A no display

[Soji]

it’s a water damage
The screen connector is burnt in the screen clip side. So I decided to chang the screen connector flex and the screen. , still no display.
I check the voltages on j8500
Pp3v3_s0 is not present
I2c_bklt_sis is 5v is present on pin 24 and 26
Smbus_smc_0_s0_sda is 3v3 is present on pin 28 and 30
I2ca_als_sda/scl 3v3 is present on pin 34 and 36
I2c_cam_scl/sda 1.7 is present on pin 38 and 40.
PP5v_so-alscam_f is present
Pp5v_s0sw_lcd is not present
Pls help me out.
No enable signal on both u8500 and 8501

 

[2informaticos]

Very likely CPU's eDP output was burnt.
Do you get external video at least?

Post diode mode to ground on all EDP_INT data lines (J8500).

 

[Soji]

Ok. Edp_panel_pwr_en not present on u8501 357
aux_n 365
aux_p 350
ml_n<o>356
ml_n<1> 337
ml_p<1> 338
ml_n<2> 357
ml_p_<2>374
ml_n_<3>339
ml_p_<3>347
mipi_data_conn_n 1342
Mipi_data_conn_p 1305
Mipi_clk_conn_n 1269
Mipi_clk_conn_p 1267
Am suspecting U8510 not creating enable signals
Pp3v3_g3h is present
Pm_slp_s3_l is present
Smc_reset_l is present
Edp_panel_pwr_en is missing

 

[2informaticos]

"Do you get external video at least?"

Check diode mode to ground at 3V3/5V_S0SW_LCD, w/ and w/o LCD connected.

 

[Soji]

3v3 W/o- 572
3v3 w - 336
5v w/0- 571
5v w -515

 

[2informaticos]

How can we get correct replies from you?
Should I write 3-4 times in the same post, to avoid more posts???
"Do you get external video at least?"

Did you even check for USB activity???

 

[Soji]

No external video to external display, but cpu is getting warm.

 

[2informaticos]

Disconnect internal LCD and check again external video.
Also let us know if you get USB activity.
PLEASE, do all test we recommend.
There is no reason to expect video, if no USB activity is detected.

 

[Soji]

Pls how will I know if there is usb activities. How will I check
I thought is just to check if there is display on the usd. Pls what will I do to check

 

[2informaticos]

HOW TO collection

I hope this "How to" collection will help our members. I will possibly modify this post in time, if updates available. Trigger SMC_ONOFF_L (PMU_ONOFF_L): It reffers to simulate power button function, when the keyboard is not connected. We need to do this when we work with the board...

boards.rossmanngroup.com

Take notes, when you find interesant information in the forum...