820-02020 no display

[tipoti]

hello, I hope you are well

There is a startup sound and I can receive images via HDMI. There is no image on its own screen. up701 had exploded. I removed it. I don't have up701 as a spare at the moment, so I couldn't replace it. Can't I temporarily short circuit pins 3 and 5 on up701?

I changed the qp800 and the result is the same
PPVOUT_LCDBKLT : no voltage
LCDBKLT_EN_L :12.4 volt
PPVIN_LCDBKLT_R : 12.4volt

 

[tipoti]

UP701
pin1:3,2 volt
pin2:3,2 volt

 

[2informaticos]

You can try to bypass UP701; nothing to lose.

 

[tipoti]

I bypassed and I get 3.2v

PPVOUT_LCDBKLT_SW still no voltage

PPVOUT_LCDBKLT : no voltage
LCDBKLT_EN_L :12.4 volt
PPVIN_LCDBKLT_R : 12.4volt

 

[2informaticos]

Check voltage at JP600, pins 4, 6, 44, 45; LCD connected.

 

[tipoti]

EDP_PANEL_1V8_EN PIN4 : 0.2 Volt 0,5,07, again 0,2
LPDP_INT_HPD PIN6: No voltage
PP3V3_SW_LCD_CONN PIN 44: 3.2 VOLT
PP5V_SW_LCD_CONN PIN 45 : No voltage

 

[2informaticos]

"PP5V_SW_LCD_CONN PIN 45 : No voltage"
You must fix this, if you want to get backlight.

UP700 is the first suspect.
Does it get enable signal?

 

[tipoti]

I changed it to up700. but still the same
PP5V_SW_LCD : 5v
EDP_PANEL_1V8_EN : 1.7 volt

 

[tipoti]

I removed the RP842 resistor and connected it to pin 5 via UP900. I read PPVOUT_LCDBKLT 50v. Is this voltage normal or excessive? but still no image

 

[2informaticos]

Is to high, like open LEDs strip.
Sometime can be solved with DFU...

 

[tipoti]

By the way, I can't see any images in the background.

 

[2informaticos]

Bypassing UP701 may not be a good idea.
CPU's eDP output may need to respect some timing diagram.

Just in case, you can try DFU...