(347) 552-2258 [email protected]

820-4924 boots to unknown screen

ytesfay80

ytesfay80

Member
I have this board that was liquid damaged. I marked these areas that had the liquid damage before cleaning and replacing components.

d7050/c7050/c7060 area
vias above kbd connector and other side
r4856/r4857/r4858/r4810/c4810 ( These components were all replaced)
isl6259 area c7150 (replaced C7116)
U1900 and C1924 (C1924 was burned so I replaced it as well as U1900)

The machine turns on when I plug in the charger and it takes about 5 seconds before it boots to the apple logo.
It takes a few seconds and loads up to the page you can see in the pictures below. I see the trackpad cursor on the page but it won't move when I use the trackpad.
When I try to turn the machine off with the power button it doesn't turn work. I have to unplug the charger and battery in order to shut it off.

https://www.dropbox.com/sh/vryoho2y7j04zsz/AABUniyEGPepOlIJWe4zjXJya?dl=0
 
ytesfay80

ytesfay80

Member
I disconnected the trackpad cable and turned it on and the same thing happened. I also plugged in another tpad cable and still nothing changed.
The trackpad connector looks perfectly clean on both sides of the board.

I also plugged in a new keyboard and that one didn't work either. I tried plugging in a usb with mac osx and hold option key but nothing happened. I also couldn't turn the machine off with the new keyboard.

Do you know what exactly those images mean? I can't find any information on it
 
Last edited:
ytesfay80

ytesfay80

Member
Okay so now I plugged in a new trackpad and cable together and this time when I booted it took me to the screen where it asks to choose the language for your computer so I think the trackpad may need replacing. When I do try to move my finger around on the trackpad the cursor does not move but I'm not sure if that is because the trackpad is not assembled into the machine.

I also plugged in another keyboard and I still cannot turn the machine off with the power button or use the option key to boot.

I checked voltages on the keyboard connector (J4813)
Pins 1/2/3 - 0v
Pin 4 - 3.42v
Pin 5 - 0v
Pin 6 - saw 1.3v and it goes down.

On the other side of the board I checked for continuity from Pin 2 of R4810 to Probe #816 and there was no beep.
There is continuity though from Pin 5 of J4813 to the via above it.

Update: I ran a wire from Pin 2 of R4810 to Probe #816 and now the power button works to turn off the machine.
I'm still not able to boot my usb stick with the option key pressed even though I see Pin 2 of J4813 jump to 3.4v when I press the left option key.
 
Last edited:
You must log in or register to reply here.
Top