| No green/orange light on charger | - PP3V42_G3H missing due to short to ground, bad D7012, bad U7090, R7080 corroding away.
- DC in cable(821-1721) corroded, and connector traces for SYS_ONEWIRE, SMC_BC_ACOK, and PP
- DC in board has corroded traces around TC7SZ08AFEAPE or MAX9940 for onewire circuit (check onewire circuit diagram on older boards like 820-2530 — this is present on the DC in board now of the *A1466/A1465/A1369/A1370 Macbook Air)
- SMC_RESET_L low due to corroded R5115 pull-up resistor, bad U5110, or bad U5000
- SMC_RESET_L low due to bad SMC
- Buck convertor that produces PP3V42_G3H has a corroded resistor on FB voltage divider line. Chip produces higher PP3V42_G3H voltage (around 8 V) kills every chip on the rail. SMC looks like shorted but replaced SMC will get killed immediately.
REMEMBER: SMC is not on if PPBUS_G3H is 8.15 V instead of 8.55 V (SMC needs to communicate with U7100 to tell it over SMBUS line to raise PPBUS_G3H from 8.15 V to 8.55 V). |
| No power, PM_SLP_S4_L is missing, draws 23–24 mA of current | - U1950 is corroded and you can't see it.
- Corrosion on probe points for SPI ROM U6100 area
- Bad clock chip U1900
- Corrosion on RTC pull-up resistors R1300 to R1303 (or C1300/C1303 shorted to ground)
- If you remove R8111 and PM_SLP_S4_L comes back, it's most likely dead CPU, check for corrosion around RAM area and if none then most likely dead CPU.
If PM_SLP_S4_L missing, we need to check these - 1. PPVRTC_G3H
- 2. RTC_RESET_L
- 3. PCH_SRTCRST_L
- 4. PCH_INTVRMEN_L
- 5. PCH_DSWVRMEN_L
- 6. SYSCLK_CLK32K_RTCX1
- 7. PP3V3_S5
- 8. PM_DSW_PWRGD
- 9. PP3V3_SUS
- 10. PM_BATLOW_L
- 11. PM_RSMRST_L
- +1. PM_PWRBTN_L
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| No power, 0 mA draw or 250 mA draw, PPBUS_G3H missing | Short to ground on PPBUS_G3H. Blown fuse F7140 for PPBUS_G3H (if it's taking 0 mA), or good fuse (250 mA), bad tantalum capacitor on PPBUS_G3H. |
| No backlight | - 0 V — bad backlight fuse, short to ground inside connector/inside screen
- 8 V — feedback trace to LP8550 burned out, or BKL_EN missing.
- 19–20 V — BKL_PWM low, or SMC_LID low due to bad DC in board. SMC_LID also comes from the trackpad, so a bad trackpad can cause this.
- 39–50 V — screen backlight cable disconnected inside screen after DIY repair, bad connector, bad screen
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No image/no backlight (external Display working) | Can both be caused by a damaged screen connector also check if L8304 is ok (low ohms), if not EDP_PANEL_PWR pulses one time (3.3V), and goes off again, as no display is detected Example: https://www.youtube.com/watch?v=62lnfgMqmQU (also a lot of corrosion on other parts of the board that needed fixing) |
| No power, PPBUS_G3H 4 V instead of 8.55 V | Bad U7100, blown R7021/R7022 |
| Any board level issue at all. | Look at J6100, and feel guilt-free in killing it. |
| Keyboard and trackpad not working | Bad trackpad cable or bad trackpad. |
| SMC_RESET_L low, but board works outside of case | Bad trackpad. Trackpad controls SMC_LID and SMC_RESET_L, so trackpad can mess with backlight. |
| Battery not recognized with X | Firstly, try a known good battery before assuming it is the board! If PPBUS_G3H is 8.15 V, SMC is not communicating properly with anything because its data line is blown. Check pull-up resistors on data line, see what may be pulling it down, most likely bad SMC (U5000). |
| Braindead | - Corrosion under U1930 on pin 6
- Bad SMC
- Some random issue you will never figure out; cry
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| USB Issues | - For left side USB, try new DC in board/DC in cable
- For right side USB issues, check L4600/U4650 area. L4600 can be open, or U4650 shorted.
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| You think PPBUS_G3H is 8.55 V | You measured the right side of the fuse, not the left side of the fuse, because you are right handed and keep the red probe of your multimeter in your right hand. Had you measured the left side of the fuse, you'd realize the fuse is blown, likely due to a short circuit. You are probably off in the wilderness, hunting why your PP3V3_S5 and PP5V_S5 are missing, before you even have PPBUS_G3H... we've all been there. |
| No audio devices found in MacOS. No chime. Volume buttons have greyed out audio adjustment. System profiler shows no speakers. | If you have ruled out the I/O Board and I/O Cable (these components are what carry the audio circuit in the A1465/6 Airs), check for PP1V5_S0SW_AUDIO. Usually, it will be lower than 1.5 volts (anywhere from 0 to 1.4 volts). It is very common on the 11" model for the 1v5 Audio Switch IC (U8040) to get crushed/damaged from the board being removed from the case, liquid damage, ultrasonic cleaner, or installing the board improperly in the housing. It usually gets cracked/chipped. Replacing it should bring PP1V5_S0SW_AUDIO to exactly 1.5 volts and restore audio devices/audio output. You can pull this chip (TPS22924) from pretty much any Air donor board (there are multiple different glass switches used across the device that will work). Make sure to use one that is not damaged. |
| No Camera (Please do not fix unless required) | Different issues - Corrosion near U1900. The capacitors above U1900 go to the camera and U1900 regulates a signal going to the webcam. Corrosion on either can cause no camera. You should replace anyways if it's corroded so this can fix your issue.
- Corrupt BIOS/bad ME region. If the ME is not cleaned properly or the BIOS dump is not proper, webcam can stop working. Flashing BIOS with a clean ME region can fix the issue.
- Bad U3900 or Camera RAM. Usually this happens from liquid, but it can happen randomly too. First step is to check for a short on the coils next to U3900 (1v2 CAM, 1.8 CAM etc.). If you have a short on any of these coils, 99% of the time U3900 is the cause and replacing it with a GOOD chip will fix the issue. If no short, you are in rabbit hole territory. You can replace U3900 or the camera RAM IC to fix the issue, but it is not always successful. There is the chance a board trace is broken internally. I would say success rate is around 80% but it's not a fun repair. You can use the Camera IC from any donor board that matches it (same chip on 2017 13" Pro board, all Air boards and some Retina boards). As long as it's the same chip, it will work (no programming). Would HIGHLY advise using the ceramic (black) version NOT the flip chip (green) version. Way too easy to kill the chip when reballing green version.
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