MacBook Pro 14-inch M2 Pro
A2779 Board Repair Guide
Board Specifications
| Parameter | Value |
|---|---|
| Model Identifier | MacBook Pro 14-inch 2023 (A2779) |
| Board Number | 820-02841 |
| EMC Number | EMC 4375 |
| SoC | Apple M2 Pro (10-core or 12-core CPU, 16-core or 19-core GPU) |
| Unified Memory | 16GB / 32GB LPDDR5 (soldered to SoC package) |
| Storage | 512GB / 1TB / 2TB / 4TB / 8TB NVMe (NAND chips soldered) |
| Display | 14.2" Liquid Retina XDR, 3024×1964, ProMotion 120Hz, mini-LED backlight |
| Power Architecture | Apple Silicon PMU integrated with T2-like secure enclave in M2 Pro die |
| Charging | MagSafe 3 (140W), USB-C (up to 100W PD) |
| Battery | 70Wh lithium-polymer, 6-cell |
| Schematic Reference | 820-02841 (community-sourced, limited availability) |
Apple Silicon Architecture: The M2 Pro integrates CPU, GPU, Neural Engine, Secure Enclave, and memory controller on a single die. Unlike Intel Macs, there is no discrete PMU chip — power management is integrated into the SoC. Board-level repair focuses on power delivery circuits, USB-C/MagSafe controllers, and peripheral ICs.
Voltage Rails Reference
| Rail Name | Nominal Value | Power State | Regulator / Source | Notes |
|---|---|---|---|---|
| PPBUS_G3H | 8.5–12.6V | G3H | Battery / CD3217 USB-C PD | Main power bus — if absent, check battery connector, CD3217 IC, fuse |
| PP3V3_G3H | 3.3V | G3H | Step-down from PPBUS_G3H | Always-on 3.3V; if absent with PPBUS present, check buck converter enable |
| PP1V8_G3H_AON | 1.8V | G3H | LDO from PP3V3_G3H | Always-on 1.8V for PMU/SoC standby logic |
| PP5V_S5 | 5.0V | S5 | Step-down from PPBUS_G3H | Standby 5V — enables USB-C PD negotiation, SMC equivalent functions |
| PP3V3_S5 | 3.3V | S5 | Buck converter | Standby 3.3V; if absent, PMU section of SoC not initialising |
| PP1V8_S5 | 1.8V | S5 | LDO from PP3V3_S5 | Standby 1.8V for I/O and SoC standby |
| PP5V_S0 | 5.0V | S0 | Buck converter | Active 5V — powers USB ports, audio codec, sensors |
| PP3V3_S0 | 3.3V | S0 | Buck converter | Active 3.3V — SSD, Wi-Fi, Thunderbolt retimers |
| PP1V8_S0 | 1.8V | S0 | LDO from PP3V3_S0 | Active 1.8V for I/O, display timing, audio |
| PPVCORE_SOC | 0.7–1.1V | S0 | Multi-phase buck (integrated PMU) | SoC core voltage — dynamic, load-dependent |
| PPVCORE_GPU | 0.7–1.0V | S0 | Multi-phase buck (integrated PMU) | GPU core voltage — active during graphics load |
| PPVOUT_LCDBKLT | 38–55V | S0 | Boost converter (LP8557↗ or equivalent) | Mini-LED backlight boost — if absent, screen dark but image visible with flashlight |
| PP3V3_LCDVDD | 3.3V | S0 | LDO | Display panel logic power |
| PP5V_USB | 5.0V | S0 | Load switch from PP5V_S0 | USB-A/C VBUS output — current-limited per port |
| PP3V3_AUDIO | 3.3V | S0 | LDO from PP3V3_S0 | Audio codec and amplifier supply |
Power Tree
BATTERY (7.78V nominal, 70Wh) │ ├── PPBUS_G3H (8.5–12.6V) ◀── CD3217 USB-C PD Controller / MagSafe │ │ │ ├── PP3V3_G3H (3.3V) ── Always-on 3.3V rail │ │ └── PP1V8_G3H_AON (1.8V) ── PMU/SoC standby logic │ │ │ ├── PP5V_S5 (5.0V) ── Standby 5V (USB-C PD, PMU alive) │ │ └── PP3V3_S5 (3.3V) ── Standby 3.3V │ │ └── PP1V8_S5 (1.8V) ── Standby 1.8V │ │ │ ├── PP5V_S0 (5.0V) ── Active 5V (USB, sensors, audio) │ │ ├── PP3V3_S0 (3.3V) ── Active 3.3V (SSD, Wi-Fi, TB) │ │ │ └── PP1V8_S0 (1.8V) ── Active 1.8V (I/O, display timing) │ │ └── PP5V_USB (5.0V) ── USB VBUS output │ │ │ ├── PPVCORE_SOC (0.7–1.1V) ── M2 Pro CPU core voltage │ ├── PPVCORE_GPU (0.7–1.0V) ── M2 Pro GPU core voltage │ │ │ ├── PPVOUT_LCDBKLT (38–55V) ── Mini-LED backlight boost │ └── PP3V3_LCDVDD (3.3V) ── Display panel power │ └── PP3V3_AUDIO (3.3V) ── Audio codec supply
Apple Silicon Power States: G3H = always-on (battery connected), S5 = standby (lid closed, PMU alive), S0 = active (system running). Power state transitions are managed by integrated PMU in M2 Pro die.
Key Components
| Reference | Designation | Function | Power Rails | Common Failure Modes |
|---|---|---|---|---|
| U3100 | CD3217 (or equivalent) | USB-C Power Delivery Controller | PPBUS_G3H, PP3V3_G3H | Liquid damage, no USB-C charge, no power negotiation |
| U3200 | CD3217 (secondary port) | USB-C PD Controller (port 2) | PPBUS_G3H, PP3V3_G3H | Single port not charging while others work |
| U7000 | ISL9240 (or equivalent) | Battery Charger IC | PPBUS_G3H, PP_BATT | Not charging, battery not detected, no PPBUS |
| U8000 | M2 Pro SoC | System-on-Chip (CPU/GPU/PMU) | All rails | BGA failure rare; usually peripheral circuit fault |
| U9100 | LP8557 (or equivalent) | Backlight Boost Controller | PP5V_S0, PPVOUT_LCDBKLT | No backlight, screen dark, boost circuit failure |
| U5500 | Thunderbolt Retimer | TB4/USB4 Signal Conditioning | PP3V3_S0, PP1V8_S0 | External displays not detected, TB devices fail |
| U4000 | Audio Codec (CS42L83 or equiv) | Audio Input/Output Processing | PP3V3_AUDIO, PP1V8_S0 | No sound, headphone jack not detecting |
| U6000 | Wi-Fi/Bluetooth Module | Wireless Communications | PP3V3_S0, PP1V8_S0 | No Wi-Fi, Bluetooth dropout |
| F7030 | Main Input Fuse | Overcurrent Protection | PPBUS_G3H input | Open fuse = no power from adapter, battery only |
| Q7200 | PPBUS Gate MOSFET | Power Path Control | PPBUS_G3H | Shorted = adapter/battery conflict, no charge |
Liquid Damage Hotspots: The A2779 most commonly suffers liquid ingress near the audio jack, speaker connectors, and USB-C ports. Corrosion appears as white/green deposits on connectors and passive components. Always inspect these areas first on liquid-damaged units.
Boot Sequence
| # | Signal / Rail | Expected Value | Condition | If Absent |
|---|---|---|---|---|
| 1 | PPBUS_G3H | 8.5–12.6V | Battery connected or adapter plugged in | Check battery connector seating; verify CD3217 USB-C PD IC; test fuse F7030 continuity (0Ω); measure PPBUS_G3H to GND resistance (norm >50Ω) |
| 2 | PP3V3_G3H | 3.3V | PPBUS_G3H present | Check buck converter enable; measure PP3V3_G3H to GND resistance (<5Ω = short); inspect for liquid damage near 3.3V regulator |
| 3 | PP1V8_G3H_AON | 1.8V | PP3V3_G3H present | Check LDO input/output; verify enable signal from PMU section; measure to GND (<3Ω = short on AON rail) |
| 4 | PMU_AWAKE | 3.3V | AON rails stable | PMU section of M2 Pro not initialising; check PP1V8_G3H_AON; verify SoC power delivery; if rails present but no PMU_AWAKE, suspect SoC or damaged PMU passives |
| 5 | PP5V_S5 | 5.0V | PMU_AWAKE asserted | Standby 5V missing — check buck converter enable; measure PP5V_S5 to GND (norm >30Ω); suspect shorted USB-C port or load switch |
| 6 | PP3V3_S5 | 3.3V | PP5V_S5 present | Standby 3.3V missing — check regulator enable; measure to GND (<10Ω = short); remove peripherals and retest |
| 7 | Power Button Pressed | Momentary LOW | User action | Touch ID / power button flex damaged; verify connector seated at board; test continuity of power button flex |
| 8 | PM_SLP_S5_L | HIGH (3.3V) | Power button release | PMU not transitioning to S0; check PP3V3_S5; verify PMU_AWAKE signal; if S5 rails present, suspect SoC or power button flex |
| 9 | PP5V_S0 | 5.0V | PM_SLP_S5_L HIGH | Active 5V missing — check S0 buck converter; measure PP5V_S0 to GND (norm >20Ω); USB peripherals or NVMe can short this rail |
| 10 | PP3V3_S0 | 3.3V | PP5V_S0 present | Active 3.3V missing — check regulator enable; measure to GND (<10Ω = short); SSD or Wi-Fi module can short this bus |
| 11 | PP1V8_S0 | 1.8V | PP3V3_S0 present | Active 1.8V missing — check LDO; measure to GND; display timing circuits often load this rail |
| 12 | PPVCORE_SOC | 0.7–1.1V | SoC requesting power | CPU core voltage absent — integrated VRM not switching; check enable signals from PMU; measure PPVCORE to GND (<0.5Ω = shorted VRM stage) |
| 13 | PPVCORE_GPU | 0.7–1.0V | GPU active | GPU core voltage absent — check GPU VRM enable; measure to GND; if CPU boots but no GPU voltage, suspect GPU power stage |
| 14 | PPVOUT_LCDBKLT | 38–55V | Display enabled | Backlight boost absent — check LP8557 enable pin; verify boost inductor and output caps; measure boost output to GND (norm >1kΩ) |
| 15 | Display Image | macOS login | All rails stable | If backlight present but no image: check eDP connector, display flex, T-CON; verify PP3V3_LCDVDD; inspect for flex cable damage |
Progressive Diagnostic Engine
Work through stages in order. Complete each stage before unlocking the next. Measure at specified test points with multimeter in DC voltage mode.
1
Always-On Rails (G3H / Power Source)
Expand ▼
2
Standby Rails (S5 / PMU Alive)
🔒 Complete Stage 1 first
3
Active Rails (S0 / System Running)
🔒 Complete Stage 2 first
4
Core Voltages (SoC / GPU VCore)
🔒 Complete Stage 3 first
5
I/O & Display (Backlight / eDP)
🔒 Complete Stage 4 first
6
Peripheral / USB (Audio · Thunderbolt · Camera)
🔒 Complete Stage 5 first
No Power Diagnostic
A2779 No Power — Initial Assessment
The MacBook Pro A2779 (M2 Pro) exhibits "no power" when pressing the power button produces no response: no fan spin, no display, no charging LED on MagSafe. This symptom has several root causes, from simple connector issues to board-level failures.
Important: On Apple Silicon Macs, the system may wake automatically when the lid is opened or when power is connected. "No power" means none of these triggers produce any response.
Step 1: Verify Power Source
- Test with known-good 96W or 140W USB-C/MagSafe adapter
- Inspect MagSafe connector for debris — the magnetic interface attracts metal particles
- Try different USB-C ports on the Mac — each port has independent PD controller
- If using MagSafe: LED should illuminate (amber = charging, green = charged). No LED = no power negotiation
Step 2: Battery Isolation Test
The A2779 has a dual-connector battery (main power + data/gas gauge). Both must be properly seated.
- Disconnect both battery connectors (requires opening case — see disassembly section)
- Connect adapter without battery — system should power from adapter alone
- If system works on adapter only: battery or battery connector fault
- If still no power: board-level fault
820-02841 PPBUS_G3H Missing — Diagnostic Flow
Step 3: PPBUS_G3H Verification
PPBUS_G3H is the main power bus. Without it, nothing else functions.
| Measurement | Expected | If Absent |
|---|---|---|
| PPBUS_G3H voltage (battery connected) | 7.5–8.4V | Check battery connector, measure battery cells directly |
| PPBUS_G3H voltage (adapter only) | 12.6–20V (depends on PD negotiation) | CD3217 USB-C PD controller failure; check fuse F7030 |
| PPBUS_G3H to GND resistance (unpowered) | >50Ω | <10Ω = short circuit on main bus |
Step 4: Fuse and PD Controller Check
- Locate fuse F7030 near battery connector
- Measure continuity across fuse (should read 0Ω)
- If open: fuse has blown from overcurrent event — do NOT replace without finding root cause
- Inspect CD3217 USB-C PD controllers (one per USB-C port + MagSafe)
- Look for corrosion, missing components, or burn marks near CD3217
Step 5: Known Issue — Small PMU Component
Per repair community reports (820-02841 boards), some A2779 units exhibit 5V 0.95A draw with no boot due to a failed small PMU-related component. Symptoms:
- Connects to adapter, draws ~0.95A at 5V, does not negotiate higher voltage
- No fan spin, no display, no further boot progress
- Often caused by liquid damage or thermal stress
Solution: Identify and replace the failed PMU support component (typically a small inductor or capacitor in the PMU power path). This requires schematic reference and microsoldering skills.
Apple Silicon Limitation: Unlike Intel Macs, the M2 Pro integrates power management into the SoC die. There is no separate "PMU chip" to replace. Board-level repair focuses on peripheral power circuits, not the SoC itself.
No Backlight Diagnostic
A2779 No Backlight — Backlight Boost and Mini-LED Driver
The A2779 uses a mini-LED backlight system with multiple LED zones. "No backlight" means the screen appears completely black, but a faint image may be visible under bright flashlight illumination.
Symptom Verification
- Boot the Mac in a dark room
- Shine a bright flashlight directly at the screen at a shallow angle
- If you can see a faint login screen or Apple logo: backlight circuit failure (display panel itself is working)
- If no image visible even with flashlight: display panel or eDP signal failure
Backlight Boost Circuit
The backlight boost converter (likely LP8557 or Apple custom equivalent) steps up PP5V_S0 to PPVOUT_LCDBKLT (38–55V) to drive the mini-LED array.
| Test Point | Expected Value | If Absent |
|---|---|---|
| PPVOUT_LCDBKLT | 38–55V DC | Boost converter not switching — check enable pin, inductor, output caps |
| Backlight IC EN pin | 3.3V when display enabled | Enable signal missing from SoC/display controller |
| Boost inductor continuity | <1Ω | Open inductor = no switching possible |
| PPVOUT_LCDBKLT to GND | >1kΩ unpowered | <100Ω = shorted boost output or LED string |
Common A2779 Backlight Failures
- Display flex cable damage: The flex cable routes through the hinge. Repeated opening/closing can cause fatigue fractures. Inspect for visible damage near hinge.
- Liquid damage to backlight IC: Liquid ingress near the display connector can corrode the backlight controller.
- Shorted LED string: If one mini-LED zone shorts, it can pull down the entire boost output. Measure boost output to GND resistance.
- Display connector not seated: The eDP/backlight connector can work loose during transport. Reseat both display connectors.
Display Connector Locations (A2779)
The A2779 has two display-related connectors on the logic board, both located near the hinge area:
- eDP connector: Carries video signal to display panel
- Backlight/camera connector: Carries backlight enable, brightness PWM, camera data
Both must be properly seated for display to function. Use T3 Torx to remove the connector brackets, then reseat the flex cables.
Flex Cable Routing: The display flex cables tuck into a groove between the logic board and case. When reassembling, ensure cables are not pinched or folded sharply.
Liquid Damage Procedure
A2779 Liquid Damage — Assessment and Recovery
The MacBook Pro A2779 is particularly vulnerable to liquid damage due to its speaker grilles, keyboard deck, and port locations. Liquid commonly enters through:
- Keyboard (travels down to logic board)
- Speaker grilles (direct path to speakers and nearby circuits)
- USB-C ports (liquid wicks into port, contacts CD3217 PD controller)
- Headphone jack (common entry point — directly contacts audio codec area)
Critical: Do NOT attempt to power on a liquid-damaged Mac until thorough inspection and cleaning is complete. Powering on with liquid present can cause additional short circuits and component damage.
Step 1: Immediate Actions
- Disconnect all power sources (adapter, battery)
- Remove bottom case (P5 Pentalobe 1.2mm screws)
- Disconnect battery immediately (both connectors)
- Press and hold power button 15+ seconds to drain residual charge
- Do NOT use rice — it does not help and introduces debris
Step 2: Visual Inspection
Look for liquid residue and corrosion. Key areas on A2779:
| Area | Visual Signs | Common Damage |
|---|---|---|
| Battery connector | White/green residue on pins | Battery not detected, no power |
| Audio jack / microphone | Corrosion on connector pins | No sound, headphones not detected |
| Speaker connectors | White residue, green oxidation | No audio, distorted sound |
| USB-C ports | Residue inside port, corrosion on flex | Port not working, no charge from specific port |
| Keyboard connector | Liquid residue on flex cable | Keyboard malfunction, keys not responding |
| Trackpad connector | Corrosion on ribbon cable | Trackpad not clicking, cursor jumping |
Step 3: Cleaning Procedure
- Remove corrosion: Use soft toothbrush with 99% isopropyl alcohol to scrub corroded areas. Work in small sections.
- Flush connectors: For enclosed areas like headphone jack, apply isopropyl alcohol into the jack and use compressed air to flush out.
- Ultrasonic cleaning: For heavily contaminated boards, ultrasonic bath with specialized cleaning solution is most effective.
- Dry thoroughly: Use compressed air, allow 24-48 hours in low-humidity environment, or use desiccant chamber.
- Inspect under magnification: After cleaning, check for remaining corrosion, lifted traces, or damaged components.
Step 4: Post-Cleaning Test
- Reconnect battery and adapter
- Check for PPBUS_G3H voltage first
- Progress through diagnostic engine stages
- Test all ports, speakers, keyboard, trackpad systematically
Prognosis: Liquid damage recovery rate depends on time elapsed before cleaning and whether the device was powered on while wet. Quick response (within hours) and no power-on attempts = best prognosis. Powered on while wet = significant component damage likely.
Short Circuit Detection Methods
820-02841 Short to Ground — Detection Methods
When a power rail measures low resistance to ground (typically <10Ω for 3.3V/5V rails, <1Ω for VCore rails), a short circuit is present. The shorted component must be identified and replaced before the board will function.
Method A: DC Injection
Apply controlled DC voltage directly to the shorted rail and use thermal imaging or finger touch to locate the heat source.
| Rail | Injection Voltage | Current Limit | Max Duration |
|---|---|---|---|
| PPBUS_G3H | 3.0V | 3A | 30 seconds |
| PP5V_S5 / PP5V_S0 | 1.5V | 2A | 30 seconds |
| PP3V3_G3H / PP3V3_S5 / PP3V3_S0 | 1.0V | 2A | 30 seconds |
| PP1V8_* | 0.8V | 1.5A | 20 seconds |
| PPVCORE_SOC / PPVCORE_GPU | 0.5V | 1A | 15 seconds |
Caution: Apply voltage lower than rail's nominal value to avoid damaging good components. Start at low current and increase gradually while monitoring temperature.
Procedure:
- Disconnect battery completely
- Set bench PSU to specified voltage and current limit
- Connect PSU positive to shorted rail test point, negative to ground
- Enable PSU output — current should draw immediately
- Use thermal camera, thermal probe, or finger to identify hot component
- If no heat detected, increase current limit gradually (do not exceed rail's normal operating current)
- The component getting hottest is likely the short — verify by removing and re-measuring rail resistance
Method B: Thermal Camera
A thermal camera (FLIR, Seek, or similar) provides non-contact heat visualization. Apply DC injection and observe which component heats fastest. Resolution of 160×120 or better recommended for SMD component identification.
Method C: Divide and Conquer
When multiple components share a rail, systematically isolate sections:
- Identify all major loads on the shorted rail from schematic
- Remove or disconnect suspect components one at a time
- Re-measure rail resistance after each removal
- When resistance returns to normal, the last removed component is the short
Common short circuit culprits on A2779:
- PPBUS_G3H short: Q7200 gate MOSFET, CD3217 USB-C PD controller, charger IC
- PP3V3_S0 short: SSD NAND chips, Wi-Fi module, Thunderbolt retimer
- PP5V_S0 short: USB load switch, audio codec, sensor hub
- PPVCORE short: SoC power stage (board likely non-repairable if SoC VRM shorted)
Normal Resistance Values (A2779, unpowered, no battery)
| Rail | Normal Resistance to GND | Shorted Threshold |
|---|---|---|
| PPBUS_G3H | 50–500Ω | <10Ω |
| PP5V_S5 / PP5V_S0 | 30–200Ω | <15Ω |
| PP3V3_G3H / PP3V3_S5 / PP3V3_S0 | 20–100Ω | <10Ω |
| PP1V8_* | 10–50Ω | <5Ω |
| PPVCORE_SOC / PPVCORE_GPU | 1–5Ω | <0.5Ω |
Measurement Points
| Rail / Signal | Test Point Location | Expected Value | Notes |
|---|---|---|---|
| PPBUS_G3H | Large filter capacitor near battery connector (top side) | 8.5–12.6V | Main power bus — measure with battery or adapter |
| PP3V3_G3H | 3.3V capacitor near CD3217 (marked 3G3H on some boards) | 3.3V | Always-on 3.3V |
| PP1V8_G3H_AON | Small capacitor near PMU area | 1.8V | Always-on 1.8V for standby logic |
| PP5V_S5 | 5V capacitor cluster (center-board) | 5.0V | Present when PMU alive |
| PP3V3_S5 | Capacitor near S5 regulator | 3.3V | Standby 3.3V |
| PP5V_S0 | Capacitor near USB controller area | 5.0V | Active state 5V |
| PP3V3_S0 | Capacitor near SSD/Wi-Fi area | 3.3V | Active 3.3V — SSD, Wi-Fi, TB |
| PPVCORE_SOC | Output side of SoC VCore inductor | 0.7–1.1V | Dynamic voltage, load-dependent |
| PPVCORE_GPU | Output side of GPU VCore inductor | 0.7–1.0V | Present during GPU activity |
| PPVOUT_LCDBKLT | Backlight boost inductor output | 38–55V | Caution: high voltage |
| Battery Voltage (direct) | Battery connector pins (without flex) | 7.5–8.4V | Measure across battery cell terminals |
| MagSafe VBUS | MagSafe connector center pins | 20V (with 140W adapter) | Verify PD negotiation |
Measurement Tips: Use multimeter probes with fine tips for SMD work. Set meter to DC voltage, 20V range for most rails. For VCore measurements, use 2V range for better resolution. Always measure with reference to board ground (any exposed ground pad or screw hole).
Required Tools
P5 Pentalobe 1.2mm
Bottom case screws (8 screws)
T3 Torx
Connector brackets, small board screws
T5 Torx
Logic board screws, port mounting screws
T6 Torx
Heat sink mounting screws (4 screws)
T8 Torx
Display hinge screws (6 screws)
T2 Torx
MagSafe connector screws (rare)
P2 Pentalobe 0.8mm
Wireless antenna mounting (9 screws)
Suction Cup
Bottom case removal
Spudger / Plastic Pry Tools
Connector disconnection, flex cable handling
Tweezers (non-magnetic)
Screw handling, small component manipulation
Multimeter
Voltage measurement, continuity testing
Bench Power Supply
DC injection for short circuit detection (0–30V, 0–5A)
Thermal Camera
Heat signature detection (FLIR, Seek Thermal)
Microscope (10–40x)
Component inspection, solder joint analysis
Soldering Station
Component replacement (fine tip, temp-controlled)
Hot Air Rework Station
BGA and SMD component removal/replacement
Isopropyl Alcohol 99%
Cleaning, liquid damage recovery
Soft Toothbrush
Corrosion removal, flux cleaning
Ultrasonic Cleaner
Deep cleaning for liquid-damaged boards
Magnetic Project Mat
Screw organization (essential for A2779's many screw types)
Frequently Asked Questions
What is the most common failure on the MacBook Pro A2779?
Liquid damage is the most common failure, particularly affecting the audio jack area, speaker connectors, and USB-C ports. The A2779's speaker grilles and keyboard provide easy entry points for liquids. Second most common is no-power conditions related to the USB-C PD controller (CD3217) or power path components.
Can the SSD or RAM be upgraded on the A2779?
No. The A2779 uses Apple's M2 Pro SoC with unified memory architecture. Both RAM (LPDDR5) and storage (NAND flash) are soldered directly to the logic board and integrated with the SoC package. There are no user-upgradeable components. Storage and memory configuration must be selected at time of purchase.
Why does my A2779 show no power after liquid damage, even after drying?
Liquid damage causes corrosion and short circuits that persist after the liquid evaporates. Mineral deposits from the liquid create conductive paths between components that should be isolated. Professional cleaning with isopropyl alcohol or ultrasonic bath is required. Additionally, if the device was powered on while wet, components may have been permanently damaged by the resulting short circuits.
How difficult is board-level repair on the A2779 compared to Intel MacBooks?
The A2779 is significantly more difficult due to Apple Silicon architecture. The M2 Pro integrates power management into the SoC — there is no separate PMU chip to replace. Repair focuses on peripheral circuits (USB-C controllers, backlight, power delivery). SoC-level failures are generally non-repairable. The board also has more layers and smaller components than older Intel models.
What tools are absolutely essential for A2779 repair?
At minimum: P5 and P2 Pentalobe drivers, T3/T5/T6/T8 Torx drivers, plastic spudgers, multimeter, and isopropyl alcohol. For board-level diagnosis: bench power supply, thermal camera or thermal probe. For component-level repair: microscope, soldering station with fine tip, hot air rework station. The variety of screw types requires a comprehensive driver set.
Can Touch ID be repaired or replaced on the A2779?
The Touch ID sensor is cryptographically paired to the Secure Enclave within the M2 Pro SoC. If the Touch ID button or flex cable is damaged, Touch ID functionality cannot be restored by replacement — it will only work as a power button. Apple can re-pair a new Touch ID module using proprietary tools, but this service is not available to independent repair shops.
What causes the 5V 0.95A no-boot condition on 820-02841 boards?
This symptom indicates the USB-C PD controller is communicating but the system is not progressing past initial power negotiation. Common causes include failed small PMU support components (inductors, capacitors in the power path), liquid damage to the charger IC, or failed power path MOSFETs. The board draws baseline power but cannot transition to higher voltage power delivery required for boot.
Disassembly Guide
Before Starting: Power down the Mac completely. Disconnect all cables and accessories. Work on a clean, static-safe surface. Keep screws organized — the A2779 uses many different screw types and lengths.
Bottom Case Removal
- Flip MacBook upside down, display hinge facing away from you
- Remove 8 P5 Pentalobe 1.2mm screws (shorter screws at front edge near trackpad)
- Use suction cup near air vent to lift rear edge
- Slide spudger along sides to release clips
- Lift bottom case off — be careful of sharp aluminum edges
Battery Disconnection
- Locate trackpad cable connector (T3 screws)
- Remove trackpad connector bracket to access battery cable
- Peel up adhesive covering battery connector
- Flip the latch and disconnect the small data connector
- Remove T5 screw holding battery disconnect tab
- Lift metal tab and slide out main battery connector
- Open lid and hold power button 15+ seconds to drain charge
Logic Board Removal
Warning: Logic board removal is complex. Multiple cable types route through narrow gaps. Take photos before disconnecting anything.
- Disconnect both speaker cables (flip latches, pull connectors back)
- Disconnect both fan cables (peel adhesive, flip latches)
- Disconnect keyboard and keyboard backlight cables
- Remove T3 connector brackets covering USB-C, audio jack, microphone connectors
- Disconnect all port connectors
- Remove wireless antenna bar (P2 Pentalobe screws — 9 screws in sets of 3)
- Disconnect antenna cables (lift straight up from connectors)
- Remove display cable brackets and disconnect display cables
- Remove T5 and T6 logic board screws (including hidden screws under adhesive pads)
- Carefully lift board while ensuring cables route through their gaps
Key Reassembly Notes
- Fan cables and keyboard cables must route through specific gaps — use tape tabs to hold them up during reassembly
- Rubber gaskets around board edges must be positioned correctly
- Display cables tuck into groove between board and case frame
- MagSafe connector screws are T2 (rare size)
- Trackpad alignment requires taping in position before tightening screws
Additional Resources
- Schematic Reference: 820-02841 (community-sourced; limited availability)
- BoardView: Check repair community forums for .brd files
- iFixit Teardown: MacBook Pro 14" 2023 teardown for visual reference
- Apple Service Manuals: Available through Apple Authorized Service Provider program
- Video Resources: "It's Binh Repaired" and "TEKDEP" YouTube channels for disassembly walkthroughs
Repair Success Factors: The A2779 is repairable at board level for peripheral circuit failures (USB-C, backlight, audio). Liquid damage is recoverable if caught early and cleaned properly. SoC-level failures (CPU/GPU die, integrated PMU) are generally not repairable — the board becomes parts-only in these cases.