MacBook Soldered SSD Not Detected: Complete Diagnostics & Repair Guide

The Problem: MacBook Shows Question Mark Folder, No SSD Detected

A MacBook Air model A1706 arrives with a critical issue: when powered on, it displays a blinking question mark folder instead of booting into macOS. This iconic error image indicates that the Mac's firmware can execute but cannot locate a bootable drive - the internal SSD is not being detected by the system.

The customer reported a liquid spill incident. Liquid damage to the MacBook logic board has likely caused corrosion on the SSD power delivery circuit, preventing the storage controller from initializing.

Why the "Question Mark Folder" Error Matters

The question mark folder is a specific error state that tells us several important things:

• The Mac firmware boots successfully - the processor, RAM, and motherboard power are functional
• The internal SSD is not being recognized by the system firmware
• The issue is NOT a software corruption (which would show a spinning globe or other macOS error)
• The problem is likely hardware - related on the SSD circuit itself

Step 1: Visual Inspection and Power Testing

The first step in any MacBook liquid damage repair is a careful visual examination of the logic board, followed by safe power testing to determine current draw.

Initial Visual Assessment

Examine the entire logic board under good lighting (or with a magnifying lamp) for:

• White or brown oxidation residue (corrosion from minerals in water)
• Discolored components - capacitors, resistors, and chips appear darker when corroded
• Liquid tracks - dried liquid paths show where water flowed on the board
• Component lift - off - solder joints separated from the board due to corrosion
• Visible damage near the SSD area, which is often a focal point for liquid accumulation

Safe Power-On Test

Never apply power to a liquid - damaged board without current limiting. Use a lab power supply set to:

• Voltage: 16.5V (Apple power standard)
• Current limit: 1–2A (normal MacBook draw is 2–4A)

If current draw spikes above the limit, the power supply immediately shuts off, preventing further damage. In this case, the board drew normal current and booted successfully - indicating no catastrophic short circuits, but power delivery to the SSD is likely compromised.

Step 2: Locating and Identifying SSD Circuit Damage

SSD power delivery circuits are among the most common targets of liquid damage because of their location and the density of components. Understanding where liquid flows on specific MacBook models is critical for efficient repair.

Liquid Flow Patterns on MacBooks

When liquid spills on a MacBook, it doesn't spread randomly. Instead, it follows the board layout and gravity:

• Liquid pools around dense component areas (chips, capacitors, resistors)
• It follows circuit traces and solder masks as natural conduits
• It accumulates in low points of the board based on the MacBook's orientation when liquid hit it
• On the A1706 specifically, the SSD circuit is a common damage focal point

Experienced technicians learn these patterns per MacBook model, as the same areas get damaged repeatedly - allowing targeted inspection and preventive component replacement.

Key Components in SSD Power Delivery

Component Assessment in This Case

Visual inspection of this A1706's SSD area revealed multiple corroded components:

• Corroded capacitor for PP1V8 (1.8V SSD power rail)
• Corroded capacitor for PP3V3 (3.3V SSD power rail)
• Corroded resistor for PP/VN2V7 NAND power
• Corroded resistor R9350 (key pull - up resistor for SSD detection signal)

Of these, resistor R9350 was the critical failure point - a single 1.3 megohm pull - up resistor that had completely failed, showing open - line resistance and eventually falling off the board during testing.

Step 3: Multimeter Testing to Identify Specific Failures

A digital multimeter is essential for pinpointing failed components. Testing resistance across suspected corroded parts quickly reveals which components need replacement.

Testing Procedure for Resistors

1. Power off the MacBook completely (disconnect battery)
2. Set the multimeter to the resistance (ohm) function, appropriate range for the component
3. Touch the probe tips to both ends of the suspected resistor
4. Read the value and compare to the schematic specification

According to the MacBook schematic, resistor R9350 should measure 1.3 megohms (1,300,000 ohms). In this case, the multimeter showed "open line"; infinite resistance - indicating the component has completely failed or corroded through.

Resistor Failure During Testing

During multimeter testing of R9350, something remarkable happened: the corroded resistor literally fell off the board. The solder joint had degraded to the point that minimal mechanical stress - the light touch of the multimeter probe - was enough to dislodge it.

This is actually a positive sign: it means the component can be cleanly removed and replaced without extensive desoldering. The technician simply needs to:

1. Remove any remaining solder residue from the pads
2. Install a new 1.3 megohm resistor
3. Reflow the solder to secure the new component

Step 4: Why This Single Resistor Caused SSD Detection Failure

A single 1.3 megohm resistor might seem insignificant, but it plays a critical role in the SSD detection circuit. Understanding this helps explain why soldered storage creates unique repair challenges.

The Role of R9350

Resistor R9350 is part of a pull - up circuit connected to the SSD controller's IUVD pin (signal for SSD presence detection). This resistor:

• Maintains a high voltage level when no signal is present
• Allows the signal line to return to a known state (logic 1)
• Enables the Mac's firmware to detect that an SSD is connected

When R9350 corrodes and fails, the signal line "floats"; it has no defined voltage level. The Mac's firmware cannot determine if an SSD is present, so it skips past the SSD in its boot sequence, resulting in the question mark folder error.

The Signal Flow Failure

Schematic Analysis

Consulting the MacBook A1706 schematic reveals that U9330 (the "Piccolo" power management chip) is responsible for generating SSD power rails. The IUVD pin on this chip serves as the detection signal. R9350 is the critical pull - up resistor that makes this signal usable by the Mac firmware.

The Piccolo chip itself appeared visually intact (no charring or component lift), but the supporting resistor had failed. This is a common pattern in liquid damage: the main power chip survives, but critical support components corrode, disrupting the circuit function.

Step 5: Microsoldering Repair - Resistor Replacement

Replacing a tiny surface - mount resistor (0402 or 0603 size) on a logic board requires precision tools and steady hands. This is core microsoldering work.

Preparation

• Clean the board thoroughly to remove corrosion residue and oxidation
• Identify the exact pads where R9350 was soldered (reference the schematic and board image)
• Prepare a clean 1.3 megohm resistor (0402 or 0603 package as appropriate)
• Set up microsoldering equipment: soldering iron, hot air rework station (optional but helpful)

Desoldering Old Residue

If residual solder remains on the pads:

1. Heat the pads with a soldering iron to 350–380°C
2. Apply flux (a chemical that helps solder flow and bond)
3. Use solder wick or a solder sucker to remove old solder
4. Clean the pads with isopropyl alcohol and a brush
5. Allow to dry completely

Installing the New Resistor

1. Apply a small amount of flux to both pads
2. Position the new resistor on the pads using fine tweezers
3. Heat the pads to 350°C, melting the solder and bonding the resistor
4. Verify the resistor is seated and not bridging to adjacent components
5. Allow to cool naturally
6. Inspect with a magnifying lens to confirm proper solder joint connection

Step 6: Testing and Verification

After resistor replacement, the MacBook must be tested to confirm the repair was successful.

Power-On Test

1. Reassemble the MacBook (or test with logic board powered via external connector)
2. Power on using a current - limited power supply (in case additional issues remain)
3. Observe the boot sequence

Expected Results

If the repair was successful:

• The question mark folder no longer appears
• The Mac proceeds past firmware initialization
• The Mac attempts to boot macOS (or enters Recovery mode if the OS is corrupted)
• Disk Utility can now detect the SSD as a connected storage device

Booting Into Recovery/Alternate OS

In this case, the MacBook's primary macOS installation was corrupted by the liquid damage. However, booting into macOS Recovery allowed the technician to verify that:

• The SSD is now detected and communicating with the Mac
• Disk Utility recognizes the drive and shows its capacity
• The NAND storage is accessible for recovery or reinstallation

The user's data remained on the SSD (recoverable) but the operating system files were corrupted by the liquid exposure. A clean macOS reinstall would restore the Mac to full functionality with data preserved.

Why Soldered SSDs Create Repair Challenges

This repair case illustrates a critical design problem with modern MacBooks: storage soldered directly to the motherboard.

The Advantage (Apple's Perspective)

• Thinner MacBook design (no space for a removable module)
• Slightly faster data access (shorter signal paths)
• Prevents user upgrades or third - party SSD installation
• Increased proprietary lock - in (users must buy Apple's overpriced upgrades)

The Disadvantage (User's Perspective)

• SSD failures cannot be fixed by replacing the drive - entire logic board replacement needed
• Liquid damage to SSD circuits requires expensive microsoldering repair, not simple part swap
• Storage capacity cannot be upgraded after purchase
• Cost of repair or replacement far exceeds cost of soldered components

The Repair Reality

Prevention: Protecting Your MacBook from Liquid Damage

The best repair is the one you never need. Protecting your MacBook from liquid damage is critical - especially since soldered SSDs cannot be easily replaced.

Immediate Actions If Liquid Spills

1. Immediately shut down the MacBook (force shut down if necessary)
2. Unplug the power adapter
3. Do not attempt to power it back on for at least 48–72 hours
4. Leave the MacBook open (keyboard facing down) to allow evaporation
5. Place it in a warm, dry location with air circulation
6. Do not use a hair dryer or oven - excessive heat can damage components

Professional Assessment Before Power-On

After waiting for drying time, have the MacBook inspected by a professional technician before attempting to power it on. They can:

• Identify corrosion on the logic board
• Test key components with a multimeter
• Clean corrosion with isopropyl alcohol before power - on
• Perform controlled power - on testing with current limiting

Powering on a wet or corroded MacBook without inspection is the fastest way to cause permanent damage. Many repairable liquid damage cases become unrepairable when the user attempts a power - on without professional evaluation.

Ongoing Protection

• Never eat or drink near your MacBook
• Use a protective sleeve or bag when traveling
• Keep your MacBook on hard, flat surfaces (not on beds or couches where spills can occur)
• Be cautious around water sources (coffee, tea, water bottles)
• Consider a keyboard cover for extra protection (though these reduce typing comfort)

When to Seek Professional MacBook Repair

Not all MacBook SSD issues can be self-diagnosed or repaired. Here's when professional help is essential:

Seek Professional Repair If You Experience:

• Question mark folder on boot (SSD not detected)
• Liquid spill followed by any malfunction
• Visible corrosion or white/brown residue on the logic board
• Kernel panic errors related to storage (search for "SSD" in crash reports)
• Extreme battery drain (suggests power delivery circuit damage)
• Any unusual behavior after liquid exposure

Why DIY Repairs Often Fail

While some computer repairs can be DIY - friendly (RAM upgrades, battery replacement on older Macs), SSD circuit repair is not:

• Requires $500+ in specialized equipment (soldering stations, microscopes, multimeters)
• Demands technical knowledge of electronics and schematic reading
• Requires years of practice to develop steady hands and solder technique
• One mistake can permanently damage neighboring components or render the board unrepairable
• Professional labs have access to proprietary schematics and testing equipment

Professional Repair: Cost and Timeline

Understanding the cost and timeline for professional MacBook SSD repair helps you make informed decisions.

Recovering Data When SSD Repair Succeeds

Once the SSD is detected again, data recovery depends on the state of the operating system and storage integrity.

Best-Case Scenario: OS Integrity Preserved

If liquid damage was minimal and only affected the SSD circuit (not the NAND storage itself):

• Boot the Mac into Recovery mode (Command + R)
• Use Disk Utility to verify and repair the SSD
• If OS boot files are intact, the Mac may boot normally
• If OS files are corrupted, perform a clean macOS reinstall from Recovery

Moderate Scenario: Data Intact, OS Corrupted

If liquid damaged the file system but not the underlying data:

1. Boot into macOS Recovery
2. Use data recovery software (DiskWarrior, Data Rescue) to scan the SSD
3. Recover files to an external drive
4. Perform a clean macOS reinstall
5. Transfer recovered files back to the repaired Mac

Worst-Case Scenario: NAND Damage

If the soldered NAND chips themselves were damaged by liquid corrosion:

• The drive may not be fully recoverable even after circuit repair
• Data recovery labs can attempt NAND chip extraction and specialized recovery
• Success is uncertain and costs can exceed $500–$1,000
• This is only viable if the data is irreplaceable and critical

This is why regular backups are critical. If this MacBook user had maintained Time Machine backups, the liquid damage would have been a hardware problem, not a data loss catastrophe.

Tools and Equipment Used in This Repair