Chosen Solution
Hello guys, can anyone help me locate the temperature sensor on this macbook? The issue I’m currently facing is the fans go high each time I turn on the laptop and it’s very very slow, the kernel task is eating whole CPU. I’ve temporary replaced the screen to confirm my thoughts and the issue was gone. So, it must be sitting somewhere on the LCD panel, anyone knows where? My guess it’s somewhere on the LCD plate since I disconnected facetime and LED light flex cables and didn’t reproduce this issue on the new screen.
Here’s what hardware test saying: https://prnt.sc/k9i9n4 Update (07/23/2018) So, basically it should be located somewhere on this LCD plate:
ok guys, just in case someone else reads this. Don’t even try to fix that %#*@ thing, the sensor is located somewhere inside the screen, not on the board I was guessing. We managed to replace that plate, soldered box flex cables without success. The screen works fine however the fans go high. No luck. These screens are impossible to fix.
Lets see if we can get a better view of your sensors. Download this great app: TG Pro. Then paste a snapshot of the main window (you may need to stretch it out a bit to get everything to shot up) Adding images to an existing question so we can see it too. Apples onboard system diagnostics as of late is more fluff than useful. Just aiming people to visit them than telling them what the issue is. Update (07/24/2018) I can’t read this chips info. It could be the sensor.
But it’s more likely within the display its self.
hy Vadim, i saw a video of Luis Rossman a few weeks ago , and he describes an issue with slow macbook and sensor problems. Take a look at it maybee it helps, or you get a clue. It is called: How to repair sensor on Touchbar Macbook when running slow without Apple diagnostic software
So, the sollution is pretty simple. Remove R8556 R8558 for board 820-00840. These are SMBUS_SMC_1_S0_SDA / SCL ALS Lines. since this laptop will fail because of the broken LCD Cable, display replacement makes zero sense.
Hi just to confirm , Had the same issue. History liquid got just right on the lcd internal board. I read the values (voltage) on all I2C datalines from the lcd and compared with a working board/working lcd and found out ALS data lines (SCL and sda) were pulled down like 1,6V instead of 3.3V. Resistance to ground on the ALS scl and sda probe points was low with the faulty lcd compared to another working one. These ALS (Ambient Light Sensor) datalines are sharing the same bus (SMC_S1_S0_SDA/SCL) than other sensors like : Temp sensor near the charger, thunderbolt and wifi, fin stack cpu proximity. So ALS messed all the bus and this is why fans go crazy. Instead of removing R8556 R8558 I just cut the traces to the lcd connector.
