iPhone 8 Plus Motherboard Repair: How We Fixed Cracked PCB & Wi-Fi Issues After Drop Damage

When a customer brought in a severely damaged iPhone 8 Plus, many would have deemed it unrepairable. The device had suffered a brutal drop, cracking the screen, shattering the back glass, and—most critically—damaging the motherboard. However, for skilled technicians, even a cracked PCB doesn’t mean it’s game over.

In this article, we’ll guide you through the full iPhone 8 Plus motherboard repair process, step-by-step—from diagnosing Wi-Fi failure to jumping micro traces with UV mask support. Whether you’re a repair technician, DIYer, or refurbisher, this guide will show you what’s possible with board-level repair.

Device Overview

Model: iPhone 8 Plus

Announced 2017, September 12

Released 2017, September 22

Defect Symptoms After Drop Damage:

• Cracked screen
• Shattered back glass
• No microphone function during calls or voice memos
• Wi-Fi toggle ON, but no signal detection

Troubleshooting Summary:

• Screen: Touch and display still functional → screen refurbishment chosen to save cost.
• Back glass: Replaced with a new one (with dock flex/microphone attached).
• No voice recording or call audio: Caused by dock flex damage; solved with back housing replacement.
• Wi-Fi issue: Root cause traced to a cracked motherboard—specifically antenna lines on the PCB.

Repair Process: iPhone 8 Plus Motherboard Fix

1. Disassemble the Phone

• Remove screen, battery, and internal screws.
• Take out the motherboard carefully.

2. Inspect the Damage

• A visible crack was found in the corner of the PCB.
• Bitmap analysis showed that antenna traces were broken near the damaged zone.

3. Stabilize the Crack

• Temporarily secured the cracked section with a UV-curable solder mask.

Luckily, the cracked part can be fixed by jumping wire.

Side A

then jump wire as below

4. Side A Repair – Jump Wire Fix

• Identify broken antenna pads using the bitmap.
• Use micro jumper wire to bridge the broken traces.
• Cover with UV mask and cure with a UV lamp.

After jumping the wire apply with the UV mask, then cure it with the UV lamp

4. Side A Repair – Jump Wire Fix

• Identify broken antenna pads using the bitmap.
• Use micro jumper wire to bridge the broken traces.
• Cover with UV mask and cure with a UV lamp.

Side B

Refer to the bitmap and fix the other side. Two wires should be jumped, then cure with the UV lamp.

Apply a little bit more of the UV mask to the cracked part

Cure with the UV lamp again to enhance the bonding

Repair Outcome

• Wi-Fi issue resolved: Signal scan and connection restored.
• Microphone works again: Voice memos and call audio back to normal.
• All functions pass post-repair testing.