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Yeah, not worth it I don’t think, always the risk of a dead CPU too. Thanks for your help.

First one is this problematic board. The other two are from two known good boards I double checked against.

Testing with diode mode, reading vs known-good(s) PP5V_S5 0.445V 0.45V PP5V_S4 0.160V 0.163V PP5V_S0 0.576V 0.576V PP3V3_S5 0.382V 0.380V PP3V3_SUS 0.366V 0.367V PP3V3_S4 0.443V 0.442V PP3V3_S0 0.370V 0.371V PP1V8_SUS 0.425V 0.422V PP1V8_S3 0.424V 0.454V PP1V5_S0 0.444V 0.446V PP1V2_S3 0.160V...

PP5V_S5 0V, pulses to 4/5V, drops and settles at 1.1V PP3V3_S5 0V, pulses to 1/2V, back to 0V PP5V_S4 0V S5_PWRGD 0V PM_SLP_S5_L 0V, pulses to 0.2V, returns to 0V ALL_SYS_PWRGD 0V, pulses to 0.2V, slow drop to 0V With battery connected PPBUS_G3H behaviour is mostly the same but somewhat more...

No change in SMC bypass mode, still draws no current when it changes from 5V to 20V on the USB meter after releasing SMC_ONOFF_L.

Checking some of the power rails connected to U7000. PPVIN_G3H_P3V3G3H starts at 8.2V then jumps to 20V after 1-2 seconds. This is meant to stay at 8.6V? PPDCIN_G3H starts at 5.2V then jumps to 20V, as expected, after 1-2 seconds.

I just re-checked PPVRTC_G3H and it does actually start at 3V then drop to ~0.5V after 1-2 seconds. Hmm. I wonder then if U7000 is detecting something wrong.

Measured them all at the same moments after turning power on. And that's my bad, I typo'd that, PMIC_SHUTDOWN_L starts at 3.3V then drops to 0V after 1-2 seconds at around the same time as PP3V3_PMICLDO does.

D'oh! PPVRTC_G3H diode mode 0.445V, good: 0.452V PP5V_G3H diode mode 0.458V, good: 0.457V PP3V3_PMICLDO diode mode 0.417V, good: 0.417V And good point re. checking those whilst PPBUS_G3H is still high, only had a couple seconds to do it but useful find: PP5V_G3H 5V then drops to 0V after 1-2...

PPVRTC_G3H diode mode OL, good: OL. PP5V_G3H diode mode 1.94V, good: 1.93V SMC_PM_G2_EN is 3.3V. PP3V3_PMICLDO 0V, should be 3.3V. No history known, no sign of corrosion but there was a thin layer of dust/fibres on the board when it was first received.

820-00244 here, doesn't boot. 20V from USB-C charger but no current. No S5 through S0 power rails. PPVBUS_LIO, PPDCIN_G3H, PP3V3_G3H and PP3V3R3V0_AON all present and correct. PPVIN_G3H_P3V3G3H 20V but should be 8.6V according to schematic? PPBUS_G3H should be 8.6V but starts at around 8.2V...

Unable to boot from USB drive. Kernel panics. Managed to capture a kernel panic whilst in verbose mode though so got some logs: panic(cpu 2 caller 0x…): Kernel trap at 0x…, type 13=general protection Wondering if this is perhaps bad RAM.

Got further with verbose mode, looks like an incomplete macOS installation. It began installation process again, ETA 24 mins, after ~30 seconds logs appeared on-screen noting launchd assertion failure and all processes would be killed. Rebooted to Apple logo & progress bar, reached end of...

Disconnecting the top case seems to have resolved the issue with it not booting consistently. Reach the FileVault login screen however there are graphical glitches (as attached). Logging in kernel panics. Recovery mode kernel panics. Internet recovery mode kernel panics. Booting from an...

Upon further testing its looks like the amount of the it needs to 'recover' and boot successfully is related to how long it was left powered 'on' before. Wondering if this perhaps could be a sensor issue.

Got an 820-00244 in that the customer explained boots to the login screen, or occasionally to the prohibitory symbol, but then very quickly slows down until it freezes and stops responding. Customer mentioned getting the "the computer restarted because of a problem" alert if they're able to log...

I see SPI activity for around about 3 seconds on this board and then the lines stay at 0V. On a known good board though I see those initial 3 seconds of activity, then activity for around about a further 5 seconds. Worth flashing a known good BIOS potentially? Otherwise I don't think I'm going...

Yeah. This one actually came in from someone I know, wouldn’t normally take a 820-00244 unless it was an obvious issue like a screen replacement. Before I throw in the towel on this. Is there a good way to verify whether this is a bad CPU or something else, say bad SPI/BIOS?

Thank you! No USB activity, tested with an optical USB mouse, no red light. One interesting behaviour I did observe when I first received this laptop was that if booted with USB-C connected to another laptop (e.g. for target disk mode) the trackpad would not even become clickable when power...

Got a MacBook 12" A1534 2017 (820-00244) here which at first glance draws power, trackpad becomes clickable, however caps lock key does not light and it doesn't output to an external display. Noticeably it gets very hot compared to a good board/laptop when left alone. Nothing visible on the...