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u7700 replaced and short is now gone. l2C_BKLT_SCL = 5V I2C_BKLT_SDA = 5V (was 3.3v) R7752/53 are not 2.4K they are 1.59k R7750/01 are 0.3 ohm still no backlight

So the short was bothering me. Backtracked it to U7700. Removed U7700 and the short was gone. Gonna order a replacement.

Well, I went back to check my work and as I was checking continuity on the lcd connector pins, it looks like i have a short to ground on I2C_BKLT_SCL. Going to have to backtrack and try to find it. I'll try to tomorrow as it isn't my work as I removed the lcd connector and jumper wires and the...

But I'm also not getting any internal DP because the 2 displayports on the side are not exporting any image. Only the HDMI on the other side of the laptop is working. I will get you the other measurements this evening. Thanks again for all your help

I thought you wanted voltage on SCL what is SCKA? I posted SCL and SDA like 2-3 comments up. You said they had to be the same. I2C_BKLT_SCL = 5V I2C_BKLT_SDA = 3.3V I don't see SCKA...

Okay Im done editing the last reply. sorry

R7752 measures 69 ohms when the power is off, but then when voltage is running it drops to OL. And with no LCD connected: I2C_BKLT_SCL = 1.9 I2C_BKLT_SDA = 1.65 Both of those pads were of the 3 damaged and needed jumper wires. and l2c-tcon_scl = 3.3v and 1.77 l2c-tcon_sca = 3.3v and 1.77

I do not have output via the displayports on the side. I still have output via hdmi. I have also put it through the ultrasonic and no change. I'm going to try and image the machine and see what happens

Yeah the 5V is steady at 28-30. DP_INT_HPD is at 3.3V I2C_TCON_SCL or SDA - couldn't be found in boardview I2C_BKLT_SCL = 5V and 1.84 I2C_BKLT_SDA = 3.3V and 1.82 EDP_BKLT_PSR_EN = 3.3V

I have 3.3v at PP3V3_S0_EDP_R and I have 5V at 28-30 of J8300. I started looking at the current sense and looking at boardview vs the schematic, which I can't read very well, but I think boardview and the schematic shows there should be a U5450. On my board, I don't have a U5450, I only have 6...

Remember I never had an image on the internal lcd. All I saw before on the cracked screen was the backlight working when I still had the good board. I was never able to see the image because the screen was cracked too much. I did have an image before, but I only had an image only on the hdmi...

After getting a non-cracked lcd I have redone the measurement on BKLT_SD and I'm getting 12.4V now.

I've gone ahead and ordered a replacement lcd just so that I can have that ruled out by default since I no longer have the good board to use. I'll let you know once it arrives and ready to test again.

I've replaced the lcd connector, but had issues due to the corrosion and ended up with 3 damaged pads. Ran wire and have continuity but still no backlight. :(

That is awesome. I'll order some. I always read the most reliable boards were somewhere around 2015, but not sure. I think they said non-retina too, but any one I see on ebay always are retina. By the way, I'm pretty positive that one of the issues, if not the main issue is the LCD connector...

Wow, that is cool. Didn't know you could get spare boards for macbooks. I get donor boards for my game consoles so I guess that makes sense. Only problem is not knowing what is good and bad on the boards...

Okay. Gonna have to place an order for the connector. Any other ic's or other components that could be an issue that I should order just to be safe?

Is it possible the LCD connector is bad because that is where the water damage was?

If that is the case then yes it has 3.3v on each pin.

Sorry about that. I thought I was making contact with the pins but it turns out I wasn't. Thought my probes were small enough as they are tiny but not tiny enough to fit underneath after all. Yes all the components around it are getting power. Need to find smaller probes.