[SOLVED] 820-2796 - No Backlight

[menatwork]

Yes. I replaced bc the screen is cracked.
I can't figure the problem.

 

[menatwork]

U9000

Pin 1 - LCD_IG_PWR_EN - 0v
Pin 2 - PP3V3_S5 - 3.30V
Pin 3 - PP3V3_S5 - 3.30v
Pin 4 - PP3V3_SW_LCD_UF - 0V
Pin 5 - PP3V3_SW_LCD_UF - 0V
Pin 6 - GND

 

[menatwork]

F8000:
8.38V


J9000:

Pin 01 - 0.16V
Pin 02 - 0
Pin 03 - 0
Pin 04 - 0
Pin 05 - 0
Pin 06 - 0.13V
Pin 07 - 0.11V
Pin 08 - 0.11V
Pin 09 - 0.11V
Pin 10 - 0.12V
Pin 11 - 0.12V
Pin 12 - 0
Pin 13 - 0
Pin 14 - 0
Pin 15 - 0
Pin 16 - 0
Pin 17 - 0
Pin 18 - 0
Pin 19 - 0
Pin 20 - 0
Pin 21 - 0
Pin 22 - 0
Pin 23 - 0
Pin 24 - 0
Pin 25 - 0
Pin 26 - 0
Pin 27 - 0
Pin 28 - 0
Pin 29 - 0
Pin 30 - 0.17V

Q9807

Pin 1 - GND
Pin 2 - BKLT_PLT_RST_L - 0V
Pin 3 - LCDBKLT_EN_L - - 8.03V
Pin 4 - LCDBKLT_DISABLE - 0.20V
Pin 5 - LCDBKLT_EN - 0V
Pin 6 - LCDBKLT_DISABLE - 0.22

Q9806:

Pin 1 - PPBUS_SW_LCDBKLT_PWR - 0V
Pin 2 - PPBUS_SW_LCDBKLT_PWR - 0V
Pin 3 - LCDBKLT_EN_DIV - 8.14V
Pin 4 - PPBUS_S0_LCDBKLT_FUSED - 8.38V
Pin 5 - PPBUS_SW_LCDBKLT_PWR - 0V
Pin 6 - PPBUS_SW_LCDBKLT_PWR - 0V

R9808:
300K

R9809
147K


U9000

Pin 1 - LCD_IG_PWR_EN - 0v
Pin 2 - PP3V3_S5 - 3.30V
Pin 3 - PP3V3_S5 - 3.30v
Pin 4 - PP3V3_SW_LCD_UF - 0V
Pin 5 - PP3V3_SW_LCD_UF - 0V

 

[dukefawks]

Right, was the old assembly working and just cracked? What is the old if you connect it now?

 

[menatwork]

The same problem - no video/back light

 

[menatwork]

I just order a new assembly.
i cant believe the problem is the board .

 

[menatwork]

both assembly I installed earlier were bad , I installed New Assembly again and everything works fine now .
Thank you Guys for all advice.

 

[bjf]

Im not an engineer and I undestand 1.003 MΩ ( 1MΩ)

Just want to make a request that we try to understand what we don't understand before we make comments like this. Not a huge deal, but let's be good students here. I'm gonna go ahead and posit that if dukefawks says it doesn't make sense, it probably doesn't make sense. Diode mode doesn't measure resistance, it measures voltage drop to ground if the positive lead is on ground.