820-4924 no video

[MDY]

Board 820-4924 from A1502 2015

This board has no video, but it chime!!

Just now at this moment I have another 100% working A1502 2015 MBP with same board 4924, so I took lcd assembly and lcd cable and tested and it is not screen problem. It is board problem.

L8300 - stable 5V
PP3V3_S0_EDP_SW - 3.3V

Is there anything more I can check? This MBP comes to me with cracked screen.

 

[dukefawks]

If there is 5V on L8300 there is an image, hold flashlight to Apple logo.

 

[MDY]

Allready did that. I did it now again with hdd and without. Wait 3 minutes and nothing. No viode, no backlight. No video at all. I have seen many backlight problems and I know what you mean but this MBP has no video!

 

[dukefawks]

SMC_LID? LCD must do something if there is 5V on L8300......

 

[MDY]

SMC_LID - 3.3V

Any idea what more to check?

 

[dukefawks]

Yes, check better if there is 5V on L8300 something must happen on the LCD.....Check external video?

 

[larossmann]

Boot into an OS using HDMI out with internal display unplugged to rule out destroyed PCH/CPU. Once that is confirmed, check C8320-C8328, people knocking that off with their fingernail is common. Also confirm FL8300-FL8303 are present.

On the 3536 and 3476 this issue could be confirmed by booting into 3S162 ASD EFI and you would get a displayport symbol error. but on 4924, no ASD.

 

[mrjoeham]

No Title

I just got the same issue for the same board 820-4924-A. The board barely had water damage on the corner where LCD connector was located from water bottle in back pack. I cleaned the area up with flux and reflowed the bad looking solder joints. Connector J8300 pin 36,37,38,39,40,41 - 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. Am I on the right track.

 

[arghhh]

Start a new thread but you really need to replace the connector and get a working test screen first before going any further.