iPhone 14 Pro Motherboard Reballing
- Aaron Harrington
- 2 days ago
- 5 min read
Interposer Reball Case Study (Rebuilding a Split “Sandwich” Board)
Watch the full repair:
Watch this repair on YouTube (with comments & chapters): https://youtu.be/CBcpp64HKYM
The Problem
This case involves a complex iPhone 14 Pro motherboard repair where the customer needed to recover data directly from the phone itself, not from a backup or third-party extraction. By the time this stage of the repair begins, the stacked logic board has already been split, and a full CPU swap has been performed.
The goal here is to rebuild the board so it’s structurally and electrically reliable again: properly prepare and refresh the solder pads, reball the interposer, and reassemble the dual-layer “sandwich” logic board.
"We need the phone to boot, charge, and run normally long enough for safe data extraction"
Step 1 – Solder Pad Preparation & Removal
[00:00:27]
Proper preparation of both the top and bottom boards is critical for a stable connection. Both halves of the logic board received the exact same preparation:
Low-melt preflow for safer removal: The initial step involves reflowing the existing solder pads using low melt solder to make the old solder significantly easier to manage and remove.
Hot air + wick instead of iron work: Hot air is utilized over a traditional soldering iron for the solder wick removal process, offering better environmental control.
Dynamic temperature control: Heat settings are adjusted dynamically throughout the process to avoid causing thermal damage to the board (for example, reducing the temperature to 220°C when appropriate).
Light oxidation cleanup: Any oxidized pads are lightly scraped to restore cleanliness and ensure a solid, highly conductive bond.
Step 2 – Interposer Reballing Technique & Tools
[00:26:38]
Precision is key when reballing the interposer. The technique utilizes specific tools and heat management strategies to ensure perfectly formed solder joints:
Magnetic reball stencil (QianLi): A magnetic reball stencil is used to ensure absolute flatness and precision during the application.
Pre-drying the solder paste: The solder paste is dried slightly with hot air prior to application to improve its overall consistency.
Hot air without a nozzle: Hot air is applied entirely without a nozzle. This guarantees an even distribution of heat across the board and prevents the stencil from warping under concentrated temperatures.
Multiple micro-adjustments during reflow: Multiple heat adjustments are made throughout the reballing phase to ensure the solder balls form correctly and uniformly.
Final flux pass and bonding: Finally, flux is applied, followed by a final hot air blast to ensure optimal solder flow and structural bonding.
Step 3 – Board Reassembly & Final Inspection
[00:40:17]
With the interposer successfully prepped, the dual-layer logic board is ready for reassembly:
Fusing the stack on a heating platform: The top and bottom boards are aligned and fused utilizing a dedicated heating platform. The process is monitored closely until the solder successfully melts and joins the two halves.
Evaluating mechanical tolerances: Minor imperfections, such as slight board bending or microscopic ball size differences, are noted during inspection but are deemed non-problematic for the overall repair.
Testing in an actual housing: The completed, reassembled board is installed back into an iPhone housing (in this case, one labeled "iPhone unavailable") to test the hardware's functionality.
Step 4 – Outcome & Customer Situation
[00:42:52]
After the reball and reassembly, the iPhone 14 Pro was tested for stability:
Normal boot and charging: The phone successfully powers on and charges normally without any rebooting issues, indicating a structurally sound repair.
Hardware isolation: To definitively rule out any hardware-induced passcode errors, additional components were swapped, including the bottom board and the NFC chip.
Customer handoff: With the hardware confirmed completely stable, the customer opted to attempt the passcode entry independently. The phone is fully stable and ready for data recovery.
The Result – Stable iPhone 14 Pro After Interposer Reball
Device: iPhone 14 Pro
Board status after this work: The interposer pads on both halves were refreshed, the interposer was successfully reballed, and the sandwich motherboard was reassembled and fused on the heating platform, then tested inside an actual housing.
How the phone behaves now: The device boots normally, takes a charge, and shows no unexpected reboots or power anomalies during testing—behaving like a healthy iPhone 14 Pro from a hardware perspective.
Final outcome:
✅ Interposer reball is completely successful. The phone is ready for data extraction by customer.
Nerd Corner (For Technicians & Repair Shops)
If you’re into the details, here are the main technical takeaways from this interposer job:
Pad cleanup workflow
Low-melt alloy first → safer, lower-temp removal
Hot air + wick instead of aggressive iron dragging
Temperature ~280 °C for final passes
Light scraping only where oxidation was visible
Interposer reball details
QianLi magnetic stencil to keep everything flat
Paste pre-dried with hot air before full reflow
Hot air without nozzle for more even heating
Multiple small tweaks to temp/airflow until all balls formed cleanly
Final flux application and reflow for proper wetting
Reassembly & validation
Boards fused on a heating platform, watching the solder melt and the stack settle
Reinstalled in an actual housing under screw tension
Verified normal boot and charge behavior with no spontaneous resets
This is the kind of board-level interposer work that isn’t offered by most phone repair shops or Apple—but it’s often what’s required when you need to access your data in its original format.
iPhone 14 Pro Data Recovery & Motherboard Repair – FAQ
Can data be recovered from a completely dead iPhone 14 Pro?
Yes, in many cases. Even if Apple or a local repair shop told you the logic board is completely dead, specialized microsoldering can often save your files. Most “dead” phones have specific short circuits or severed connections. By repairing the board at the microscopic level, we can often bypass the damage, power the phone on, and safely access your data for backup.
Why did my local shop say my iPhone 14 Pro motherboard cannot be fixed?
The iPhone 14 Pro uses a complex “sandwich” motherboard design—essentially two boards fused together by a middle layer of microscopic solder joints called an interposer. Hard drops, bends, or liquid damage can sever these connections. Most repair shops do not have the equipment or expertise to safely split the boards, diagnose the inner layers, and perfectly rebuild (reball) that interposer to get the phone booting again.
My iPhone 14 Pro is stuck in a boot loop or randomly restarting. Is my data safe?
In most cases, yes. Boot-looping (flashing the Apple logo), sudden shutdowns, or charging failures are classic symptoms of motherboard trauma or a failing connection between the two halves of the board. I specialize in stabilizing these failing connections to create a secure, complete backup of your photos, texts, and files.
Do I need a “board swap” to get my data back?
Not necessarily. While severe cases sometimes require moving the “brain” of the phone to a donor board, many data recovery jobs simply require identifying the faulty component or rebuilding the interposer connection on your original motherboard. The goal is always the safest, most efficient route to retrieving your data while keeping everything tied to your own hardware.
Do you offer nationwide mail-in data recovery for the iPhone 14 Pro?
Absolutely. I accept mail-in data recovery and advanced microsoldering cases from all over the United States. You securely ship your damaged device to my lab, I perform the necessary board-level diagnosis and repair, and when recovery is successful, you get your rescued data back on a flash drive or via a secure cloud download—along with your repaired phone where possible.
Need Advanced Motherboard Repair for Data Recovery Purposes?
I run iBoard Repair, a dedicated iPhone data recovery and microsoldering lab.
If your iPhone 14 Pro or 14 Pro Max needs a CPU swap, has a split sandwich board, or you’ve been told it’s “unrepairable,” there’s still a good chance the board can be stabilized and your data can be saved.
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