Apple MacBook Air A1466
| Problem Description | Symptoms | Solution | Source |
|---|---|---|---|
| No power. | - Draws ~266mA | Likely shorted tantalum capacitor on PPBUS_G3H or one of its sub-rail | Source |
| No power. | - Draws 6-19mA - May or may not be water damaged. | Check R7245 and clean contact pa | Source |
| No power. | - Draws 20-25mA - Possibly PM_SLP_S4_L missing. | Check R7245 and clean contact p | Source |
| Battery doesn’t hold a charge | Before you replace the battery, try simply disconnecting and reconnecting the battery. “No knowledge as to why this works, yet action restores functiona | Source | |
| No backlight. | Check diode readings around U7701, if the values are between 0.543 and 0.511 then U7701 is likely the pr | Source | |
| No light on charger. | - SMC_RESET_L voltage is pulled low. | Possible corrosion or debris on JTAG con | Source |
| No backlight. | - Reset PRAM. - Check CPU_VCore, if not present check R7550 and L7550 on the PPVCORE_S0_CPU_REG rail - If both good, check Q7550 for voltage on input VIN. If present, but nothing on TB and BG, check U7400 for resistor CPUIMPV_TON, tends to be commonly blown. - Check backlight circuit in Diode Mode, should measure around 0.530 Ω, if it does, check fuse F9700, if blown replace it. - Reflash MX25L6406E. Dump | Source Example Example | |
| 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 & PP5V_S5 are missing, before you even have PPBUS_G3H… we’ve all been there. | Source | |
| No display. | - U7400 resistor CPUIMPV_TON is blown | Caused by damaged backlight resistor and fuse | Source |
| No display. | - Fuse F9700 is blown. | Caused by damaged backlight resistor and fuse | Source |
| Random shutdown | - Corrosion at U7090 (makes PP3V42_G3H), BIOS chip, several probe points, and capacitors. | Visual inspection and repair of corrosion areas. Example: U7090 replaced, several capacitors replaced, and probe points revived. | Source |
| Boot Loop | - 10 mA to 550 mA repeatedly before settling at ≈350 mA. | Thermal camera revealed U4500 was damaged due to liquid exposure. Replace U4500. | Source |
| No green/orange light on charger | - Check for PP3V42_G3H missing due to shorted D7012, bad U7090, or corroded R7080. - Corrosion on DC in cable traces or DC in board (one-wire circuit components damaged). - SMC_RESET_L low due to corroded R5115 pull-up, bad U5110, or bad U5000. - If PPBUS_G3H reads 8.15 V instead of 8.55 V, SMC communication issue. | Source | |
| No power, PM_SLP_S4_L missing | - Draws 23–24 mA current. | - Corrosion on U1950 or SPI ROM U6100 probe points. - Bad RTC chip U1900 or pull-up resistors (R1300–R1303). - For PM_SLP_S4_L issues, check RTC_RESET_L, SYSCLK_CLK32K_RTCX1, PP3V3_S5, PM_DSW_PWRGD, and related rails. - If R8111 removal restores PM_SLP_S4_L, suspect dead CPU. | Source |
| No power, PPBUS_G3H missing | - 0 mA or 250 mA draw. | - Short to ground on PPBUS_G3H. - Blown F7140 (0 mA draw) or bad capacitor on PPBUS_G3H. | Source |
| No backlight | - For 0 V: Check backlight fuse or short to ground in the connector/screen. - For 8–12 V: Inspect feedback trace to LP8550. - For 19–20 V: Verify BKL_PWM or SMC_LID signals. - For 39–50 V: Screen backlight cable may be disconnected or damaged. - Inspect cracked L7701 pin and continuity. | Source | |
| No power, PPBUS_G3H at 4 V | - Replace bad U7100 or blown resistors R7021/R7022. - If U7000 is bad, check and replace R7120–R7122 or R7150–R7152. | Source | |
| Keyboard and trackpad not working | - Test with known good keyboard/trackpad. - Inspect and replace bad R4830 (0 Ω resistor). | Source | |
| Not powering on but charging | - Replace clock chip. - If fan continuously spins, inspect clock-related circuits. | Source | |
| Smoke coming from SSD connector | - Replace SSD connector. - Insulate shorted PP3V3_S0 pin to ground at SSD. | Source |