MacBook Pro A2251 no Display 820-01919-A

[mferna14]

Hi Dears, working on this MacBook Pro A2251 no Display (Logic Board 820-01949-A). The problem was liquid spill inside the screen, other than this the laptop was working fine. I replaced with a Brand new known good LCD Screen. After I turned on, no display. I have been replacing screens for a long time & without errors. I rechecked the LCD screen with another laptop & it was working. Now in this laptop no display at all. I checked the backlight voltage coil, on 1~2 volts out here. Caps volts even the same, out out I believe it should be around 47~55 volts. Can some help me & guide me, what going wrong with the logic board? Appreciate your help. Thanks

[Stephen]

Re: MacBook Pro A2251 no Display 820-01919-A

Did the screen previously that was water damage at least turn on with a backlight?

[Stephen]

Re: MacBook Pro A2251 no Display 820-01919-A

Also if the lcd is what got damaged I would suggest replacing the LVDS cable connector on the board with a new connector and start there, before checking for bad caps etc, start off small and easy with the LVDS connector for the lcd. Those are known to fail.

[mferna14]

Re: MacBook Pro A2251 no Display 820-01919-A

Thanks Stephen for the reply. First thing what I did was replaced the LVDS cable when I removed the logic board, & before I replacing the LCD, there was 100% Backlight & I could see & read all on the screen, only there was liquid smugs all over the LCD. This is why I was replacing the LCD Screen. & there after when no display I started to check the volatges on the coil & the caps. Any other tips pls. will be greatly appreciated. Thanks

[Stephen]

Re: MacBook Pro A2251 no Display 820-01919-A

Have you put the bad display back on to verify it is turning on still? If so this means the new display is faulty and you need a replacement.

[mferna14]

Re: MacBook Pro A2251 no Display 820-01919-A

I will do this., but I am sure the new LCD screen is fine too. I will do it tomorrow & let you know. Thanks

[mferna14]

Re: MacBook Pro A2251 no Display 820-01919-A

Today I checked throughly as I was tied up with work. 100% its the main logic board problem. The Old screen is working on another similar logic board of A1706. & today, I plugged in the power adaptor & guess what, I got the display on the one I am having display problems, I turned it off & on 2 times, I did get the display again & booted well in OS. But on the 3 time on/off, the display got blank again, & thereafter nothing on the screen. Any tips regarding the main logic board 820-01949-A. Any known problem component which is causing the display to disappear, the AMPS are perfect .49 ~ .60 without the battery??? Thanks