Hello everyone, I have a very interesting issue on this M1 i haven't seen on previous gen intel boards.So i'll give the back story on what happened to this mac. I purchased it damaged from a friend so i knew they didn't open it up. They spilled lemonade on the keyboard and it shut off. When i opened it up, there was surprisingly little liquid actually on the motherboard itself. Most of the damage was located in the LCD/Keyboard backlight area but even so, it didn't look that bad. I cleaned it very well but no components had to be replaced as they all tested fine (just checking for shorts/diode readings) so i attempted to boot. When i booted it went straight to the restore screen with the exclamation point. I had no access to any recovery partition at all. The only thing i could do was restore with apple configurator 2. After restoring the computer came back to life but did not detect the wifi chip. I ran apple diagnostics and it also indicated an issue with the wifi chip. Because of this the computer boot loops every minute. I can load into the OS and use the computer for about a minute before it shuts off by itself and boots again. When it boots back up i get a kernel panic message. So i started to investigate the wifi circuitry to see if anything obvious was damaged there, and i practically found nothing. no shorts, all components read to spec, i am getting all of my VDD power rails into the wifi module, as well as .634V on my PMU_CLK32K_WLBT data line, and i also have voltage on my WLBT_PWR_EN. During the boot sequence, the moment i receive WLBT_PWR_EN voltage i get a blip of 1.2V on WLBT_RESET_L indicating it tried to start but immediately shut off. After that i never see any more attempts to bring up the wifi module until the machine reboots again. i never see the 1.8V rails turn on from the wifi chip. With no apparent shorts, and all voltages present i see no reason this module wouldn't work, unless an overvoltage event occurred near the liquid spill and damaged the chip internally. I'm sure others have had this issue and i'm just trying to figure out if someone has a solution, or knows whats going on. Are these wifi/bt modules easy to kill? Are they replaceable? i imagine there is some kind of encryption that would prevent just a simple swap.
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OpenBoardView — https://github.com/OpenBoardView/OpenBoardView -
Re: A2338 M1 Liquid Damage and WiFi dead
Well crud. Looks to be what happened to mine. I also traced it down and found a 500 ohm to ground short to the wifi chip. What a terrible design.Comment
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50 ohms is normal resistance and that's not the problem. There is a via hole under the test point tpl002, there is a corrosion signal "wlbt_pwr_en" does not reach the wifi moduleComment
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