Reece

I have 2 A1706's at the moment, both suffered very minor liquid damage in different places, but both have the same issue....

I own an A1708 which needed a battery and keyboard replacement, which I got around to looking at a couple of weeks ago....

I have the opportunity to get hold of some A1706/A1707/A1708 keyboards, and was wondering if anyone has replaced the...

Got a Mac Mini in for the fan connector replacement which has been replaced, however the wires going into the power button...

Been getting a lot of these recently with F7140 and/or F7141 being blown, so I have pretty much used all fuses from donor...

Got an 820-00045 in for repair at the moment (liquid damaged). Ultrasonic cleaned it and there is damage to Q7430, a...

Just wondering if the 2012 hard drive cables work fine in 2009/2010 Macbook Pro 13" models? 2009/2010 cables seem like...

Got a MacBook Retina 13" 2015 which needs a battery replacement. I ordered a 3rd party battery which was claiming it was...

Wonder if anyone has a good source for SSDs on the MacBook Air/Retina 2013+ in the UK? There doesn't seem to be a...

Was water damaged, has been cleaned in an ultrasonic cleaner, but the left USB is not working and it is showing a dim...

The 2011 and 2012 Airs can run very slowly if there is an issue with the battery, for example, if the wrong one is used or if there is a fault with the battery. This will cause the cursor to lag too, and is only an issue which can occur on the 2011/2012 Airs, it doesn’t happen when there is a battery fault on the newer models. I would also suggest checking the whole logic board for liquid damage, since it likely has some damage on the backside. Check the trackpad PCB and cable, in case there is corrosion (although this is unlikely to be the cause, since the cursor lagging will usually be battery or sensor related). Check the board and hopefully you will find some corrosion to point you in the right direction

Check the logic board thoroughly for damage; blown components or damaged sensor circuits can cause this issue. Test it will just the charging port, fans, SSD and trackpad connected; if the fans still go full speed it will be logic board related. If it is logic board related, I would suggest taking it to a repair centre to check out; a decent repairer will know areas to check and will determine what is causing the fault.

@honzo I assume you resoldered U8900 before attempting all this, since this is a common fault on early 2013 models? If not, I hope you didn't mess up U9100 by reballing... Haven't got a schematic in front of me at the moment but I believe U8900 sends a GPU good signal to U9100 which will allow U9100 to produce the required signals for backlight and image. If U8900 is not sending the PGOOD signal to U9100 (which happens due to bad solder joints on the chip), there will be no image or backlight on the screen whatsoever.

I had one with this issue a while back, a 13" 2015 model. IIRC, it would only show the diagonal stripes when in an OS, or intermittently (holding option key on boot would show picture fine I think). The issue was related to the logic board, I believe it was related in some way to the CPU integrated graphics. I didn't spend too much time on it though, since there was no physical or liquid damage present to suggest a cause, but it was definitely logic board related. Not a very common issue, but seems to be a rare fault on these and have seen 1 or 2 A1278 models with the same problem. Try outputting video to an external screen to be sure and if you are still having the same issue, try a replacement logic board.

Will be a hardware issue; I would order and try a trackpad and cable to test it with. Inspect both sides of the logic board for liquid damage first, and also the battery PCB, before ordering the parts. If you have a multimeter to hand, I would suggest first measuring PP3V3_S4 (get a schematic and board view for 820-4924), since this is the voltage going to the trackpad enabling haptic feedback to work. This is also a power rail present in hibernation, and may be low/missing, causing the MacBook to completely turn off when it goes into a deep sleep (asleep for over a minute), causing the other issue you mention. I would inspect, measure the voltage, then order the parts. No way of determining the cause without trying test parts unfortunately

Does the screen randomly go to a lit up black screen? There is a common CPU issue on these where it will usually do that and restart, sometimes showing some pixel width slightly diagonal lines going down the screen. To replace the LCD cable (not guaranteed to fix your issue), follow the below guide. Step 28 shows the LCD cable (unscrew the PCB and it unplugs from the other side), you can ignore a lot of the steps before this (removing the audio board, etc) since you don't have to remove the whole assembly. Retina MacBook 2015 Display Assembly Replacement

LCD cable issue, reconnecting logic board side and/or screen side 99% of the time fixes the issue (remove screen, hinge cover, WiFi antenna screws and LCD PCB screws). If it doesn't, try a new cable

Yes it's separate, you can reuse the old one

Removable, same as the older models. 2016/2017 Airs are the same as the 2015's; only difference being the updated processor.

Try disconnecting the battery indicator; this can interfere with the battery data lines if liquid damaged, preventing the battery from being recognised. This is unlikely to resolve the issue though I’m afraid. Sounds like your colleague disconnected the battery with a metal tool, or shorted it another way, which can send battery voltage to the SMC through the data line, killing it. Common issue and hear this happen a lot on the forums. Only solution is replacing the logic board or solder a SMC from a donor board.

Curious what the shielded port is for. I am skeptical that it is for reading the SSD, since the SSD usually needs communication with the SMC, CPU and requires 3.42v and 3.3v S0 voltages to power it (among other circuits/signals). Unless the reader tool which plugs in independently powers the SSD ICs, I think it will be unlikely.

I think there is a high chance it is just a shielded diagnostic port, to better protect it from liquid damage. On older models (Macbook Air is a good example) if the diagnostic port gets liquid damaged, Apple can no longer use the port to read important voltages. It can also prevent the Macbook from working correctly, which is why a lot of diagnostic ports get removed by 3rd party repair centres.

In time, we will see I guess...