820-4924-A no image , no backlight

[mrjoeham]

MacBook Pro no image, no backlight 820-4924-A. The board barely had water damage on the corner where LCD connector was located from a water bottle in back pack. I cleaned the area up with flux and reflowed the bad looking solder joints. Connector J8300 pin 38,39,40,41 - Connector J4915 pin 4, U8300 and on the reverse side of board the only thing I saw that had corrosion was C7778, check for short here and none.. I cleaned it all up and reflow with new solder. It boots up and chimes and also with the external screen via with HDMI output I got image and can use the laptop. The LCD male connector on the display looks clean and solid. I took measurements at the board connector and only have 5.1v at pin 3 and 5.1v on pin 4 and all other pin is 0v. I check C8320- C8328 all is present ... I don't have extra display to test. I verified no image with flashlight on backside thru apple logo. Am I on the right track.

 

[larossmann]

Connector J8300 has 30 pins. Also you need a known good LCD with something like this. What voltage do you have on both sides of R8319? What voltage on pins 28/29/30 of the LCD connector?

 

[mrjoeham]

Luis, I was able to find another good screen. With good known screen, it works so the old LCD assembly is bad. The LCD assembly is a straightforward circuit, have you ever had to fix the LCD assembly itself? What's your recommendation, I am going to try to fix the LCD assembly with already confirming with the customer that he will also need New assembly. Where can I buy a new one in case this one isn't repairable. Thanks for your help.

 

[dukefawks]

Swap the LCD, besides that there is nothing you can do.

 

[mrjoeham]

ok, thanks Duke, going to go ahead and get new LCD, but im going to see if I can tinker with the other one anyway, will post what I find out. thanks you