Apple introduced Parts and Service History in iOS 15.2, and the system has kept evolving as Apple expands its repair verification and calibration requirements. iOS 27, released on September 14, 2026, is now the current major version of iOS.

This guide explains the rules Apple documents today, and what they mean for iPhone repair and refurbishment.

What does "Unknown Part"  mean?

After a repair, go to:

Settings › General › About › Parts and Service History

Depending on the iPhone model and its repair history, Apple may show one of several statuses next to a replaced component.

According to Apple's current support documentation, a component can show Unknown when it:

• isn't a genuine Apple part;
• isn't working as expected;
• hasn't completed Apple's verification or pairing process after the repair;
• has been modified, or otherwise can't be verified.

Note An Unknown Part message can also affect the device's trade-in value.

Does "Unknown Part" affect how iPhone works?

Not necessarily.

Apple states that messages in Parts and Service History generally don't affect your ability to use iPhone, unless the specific message says otherwise.

Repair status can still matter for specific features. For example, when a repair requires calibration and that process isn't finished, Apple says Face ID may not be available to unlock the device, authorize payments, or sign in to apps until calibration is complete.

So don't read an Unknown Part message as a hardware failure on its own. The questions that matter are whether the replacement component works as it should, and whether the required repair and calibration process can be completed.

How long does the Unknown Part notification last?

Apple's current support documentation says iPhone shows an Unknown Part notification:

• the first time the device is unlocked after the repair;
• again five days later.

The Unknown Part information also stays in Parts and Service History. The repair record remains part of the device information Apple maintains.

How to use Repair Assistant on iPhone

Apple's Repair Assistant is designed to finish supported repairs and calibrate supported replacement components on supported iPhone models.

Before you start

• Update iPhone to the latest available version of iOS.
• Connect iPhone to Wi-Fi.
• Make sure the device has enough battery power.
• Open Settings › General › About.
• Open Parts and Service History.
• Choose the component that shows Finish Repair.
• Follow the onscreen instructions to finish the repair.

Apple notes that this process doesn't support captive networks, or networks that require 802.1X authentication.

If Repair Assistant can't finish the repair, check the network connection, device software, battery level, component installation, and whether the required Apple Account information is available.

What changed with iOS 27?

iOS 27 was released on September 14, 2026. Apple's major iOS 27 update focuses on system improvements, Apple Intelligence, Siri, parental controls, performance, and other platform features.

For repair and refurbishment businesses, one change worth noting is Apple's updated Ready for Repair or Trade-In process.

In iOS 27 or later, Apple directs you to:

Find My › choose your device › More › Repair or Trade In › Enable

This workflow prepares a device for repair or trade-in. In many service situations it replaces the older practice of turning off Find My before a repair.

6. Parts and Service History in apple's current documentation

apple's current support documentation covers more component types than the original battery and display repair workflow. Depending on the iPhone model, Apple can provide repair-history information for components including:

• Battery
• Display
• Front camera
• Rear cameras
• Enclosure
• and more

The exact components available depend on the iPhone model.

That means a technician shouldn't judge a replacement part only by whether a display or battery shows Unknown. Check the full repair history, and the status of every serviced component.

What about third-party iPhone displays?

Three points matter most for aftermarket displays.

Functionality comes first

An Unknown status doesn't necessarily mean the display is faulty. apple's current documentation lists several possible causes, including a non-genuine part, a malfunction, incomplete verification or pairing, and modification.

Repair status matters

If the replacement is a genuine Apple component and the repair isn't finished, the device may show Finish Repair until Repair Assistant completes the required steps.

Check current iOS behavior before refurbishing at scale

Apple's repair verification and calibration system can change with future software releases. For shops that process large volumes of devices, it's worth testing replacement parts against the current version of iOS before placing a bulk order or starting a refurbishment run.

For repairs where the original front sensor flex is damaged or non-genuine, REWA Shop offers diagnostic-compatible iPhone displays with a front sensor flex — an additional aftermarket option for technicians who need to run diagnostics after a display replacement. Evaluate these displays the same way: display functionality, diagnostic results, iOS compatibility, and Parts and Service History.

What about third-party iPhone batteries?

The same principle applies to battery replacement. After installation, check:

Settings › General › About › Parts and Service History

Depending on the component and the repair process, a battery may show as Genuine, Used, Unknown, or another applicable repair status.

Apple also notes that Parts and Service History information is kept as part of the device information, and used for purposes that include safety analysis and improving Repair Assistant.

For refurbishment businesses, evaluate a battery replacement on:

• Battery functionality
• Battery health reporting
• Repair and calibration status
• Parts and Service History
• The current version of iOS
• Whether any required repair process can be completed

REWA Shop also offers diagnostic-compatible iPhone batteries designed for supported repair and diagnostic workflows, giving repair shop an additional aftermarket option when replacing an iPhone battery. Technicians should still check battery performance, system information, Parts and Service History, and compatibility with the current version of iOS.

iOS 27 Repair Checklist for Refurbishment

Before buying or installing third-party replacement parts, run through the following checks.

1. Confirm the iOS version: Test the part against the version of iOS currently installed on the target device.
2. Check Parts and Service History: Look for Genuine, Used, Unknown, Unverified, or Finish Repair.
3. Test every core function: For displays: touch, brightness, image quality, proximity sensor behavior, and related functions. For batteries: charging, battery health information, temperature, and power delivery.
4. Finish Repair Assistant when it applies: If the component shows Finish Repair and is supported on that iPhone model, follow apple's supported repair workflow.
5. Check the device before resale: Review Parts and Service History before handing a refurbished iPhone to a customer or listing it for resale.
6. Test current firmware before buying in bulk: Don't assume a component that worked on an earlier version of iOS will behave the same way after a major iOS update.

Frequently Asked Questions

Does an Unknown Part message mean iPhone is damaged?

No. An Unknown Part message means Apple can't verify the component through its current validation process. Apple lists several possible causes, including a non-genuine part, a malfunction, incomplete verification, or modification.

Can I remove an Unknown Part message?

It depends on the cause. Repair Assistant can complete supported repair and calibration steps, but a third-party component shouldn't be described as a genuine Apple part just because Repair Assistant was run.

Does an Unknown Part affect iPhone performance?

Not necessarily. Apple states that Parts and Service History messages generally don't affect how you use the device unless the message says otherwise. Individual repair or calibration issues can still affect specific features.

Can a used Apple display show “Used”?

Yes. Apple states that on iPhone 12 and later with iOS 18 or later, a display that has been used in, or installed in, another iPhone can show Used.

Does iOS 27 change the Parts and Service History system?

iOS 27 continues apple's repair verification and Parts and Service History framework, while adding device-management features such as Ready for Repair or Trade-In. Use apple's current support documentation as the reference for the latest supported repair workflow.

Should repair shops test parts after every major iOS update?

Yes. Apple can change repair, verification, calibration, and device-management behavior through software updates. For professional refurbishment, testing replacement parts against the current production version of iOS is a practical way to reduce unexpected compatibility issues.

Conclusion

An Unknown Part message after an iPhone repair doesn't necessarily mean the replacement component is defective.

Under apple's current iOS 27 documentation, the core concepts remain:

Parts and Service History → Finish Repair → Genuine / Used / Unknown / Unverified

For repair shops and refurbishment businesses, the most reliable approach is to evaluate hardware functionality and apple's current repair status together, rather than treating an Unknown Part message on its own as a failure.

As iOS continues to evolve, test replacement parts against the latest production firmware before committing to large-scale refurbishment or purchasing decisions.

An iPhone battery is three things at once: a lithium cell (the energy store), a Battery Management System (BMS) board that manages charging, and an authentication IC the chip iOS uses to verify the part is genuine. Each tier handles all three differently.

iPhone Battery Comparison

A battery consists of three parts: a lithium cell (the energy store), a battery management system (BMS) board for charging, and an authentication chip for checking authenticity. All three are handled differently by each tier.

*Apple extended design cycle life from 500 cycles (iPhone 14 and earlier) to 1,000 cycles for iPhone 15 and later a meaningful improvement most buyers overlook.

What is a diagnostic-compatible battery?

Batteries manufactured by third-party iPhone parts brands like REWA include a proprietary authentication chip pre-programmed to pass iOS' encrypted hardware handshake. Therefore, health reports are accurate, warnings aren't persistent, and there is no need to transfer chips.

The BMS Authentication Problem

Since iPhone XS, Apple batteries contain an authentication IC that performs an encrypted handshake with the logic board. Whenever the handshake fails, iOS disables the Battery Health display and flags the part as incompatible, mismatched, or absent. There are two types of aftermarket iPhone batteries: ones without the IC entirely and those with a generic IC that fails the check. The battery still charges and works, but its health data is permanently unavailable.

The Used-Pull Nuance

A used-pull battery is a genuine Apple battery that has already been installed and used in another iPhone. On supported models, iOS can verify the battery as a genuine Apple part after the repair and calibration process is completed. For iPhone 15 and later running iOS 18 or later, Settings will show the battery as "Used" rather than new.

Because the battery has already been used, its battery health, cycle count, and first-use history don’t reset when it is moved to another phone. So if a supplier sells a battery at 85% health, that means the battery has already degraded to roughly 85% of its original maximum capacity it is not equivalent to a new battery. Apple also notes that previously used parts can have inconsistent performance depending on their prior use and condition.

For that reason, always buy used-pull batteries from a trusted supplier with clear grading standards, and check the reported battery health, cycle count, physical condition, and warranty whenever possible.

iPhone Screen Comparison

An iPhone screen replacement involves more than simply swapping the glass and display. The overall result depends on the display technology and quality, such as OLED or LCD, the touch and display electronics that control how the screen communicates with the iPhone, and the calibration data used for features such as True Tone, brightness, and color accuracy. Apple calibrates genuine replacement displays through its repair process, and on supported models Repair Assistant installs the required calibration data after installation.

Lower-quality aftermarket screens may still work, but they can differ noticeably in brightness, color accuracy, touch response, power consumption, and True Tone performance. In practice, each screen tier handles these areas differently, which is why two replacement displays that look similar on paper can provide very different everyday experiences.

Why LCD is a Downgrade on iPhone 12 and Later

Starting with the iPhone 12, Apple moved its main iPhone lineup to OLED displays, while the iPhone SE continued using LCD. That means an “LCD screen for iPhone 14” is an aftermarket conversion rather than a replacement that matches the display technology Apple originally designed for the phone.

These budget LCD replacements can still make the phone usable and may cost considerably less, but they generally cannot match a good OLED for deep blacks, contrast, color quality, brightness, and viewing experience. OLED pixels can also switch off individually when displaying black, while an LCD relies on a backlight that remains powered, so Dark Mode does not provide the same display power-saving advantage as an LCD replacement.

Exact brightness varies widely between aftermarket screens, so it is better to judge a specific panel by its tested specifications rather than assuming every budget LCD falls within a fixed unit range. Apple continues to use OLED displays in its new iPhone 17 models as well.

Soft OLED vs. Hard OLED vs. LCD

Apple introduced OLED with the iPhone X, and its modern OLED iPhone displays use flexible panel construction rather than the rigid glass-substrate panels commonly sold as hard OLED replacements. In the repair market, soft OLED generally refers to an OLED built on a flexible plastic substrate, which can better tolerate bending and impact than a rigid glass-based hard OLED panel.

Hard OLED screens are usually cheaper, but their rigid construction makes the display layer more vulnerable to cracking after a drop. LCD replacements work differently: they need a backlight behind the entire panel, so they cannot switch individual pixels completely off for true black, are typically thicker, and do not get the same dark-screen power-saving advantage as OLED, where each pixel produces its own light. 

The Diagnostic-Compatible Screen Breakthrough

REWA's  diagnostic-compatible aftermarket iPhone screens are designed to work with Apple's Repair Assistant without requiring technicians to transplant the original display IC or manually program True Tone data. On supported models, the replacement can complete the diagnostic process without triggering the usual "Unknown Part" warning, while features such as True Tone remain available without the traditional chip-transfer procedure. REWA markets this as a major step forward for aftermarket screen repair because it removes one of the most difficult and time-consuming parts of display replacement. 

Which Part Should You Actually Buy?

The right tier depends on the device, the use case, and who is doing the repair. These are the scenarios that matter in practice.

Frequently Asked Questions

Will a third-party iPhone battery show an Unknown Part message?

It can, but not every third-party battery behaves the same way. Apple says an iPhone may show Unknown when a replacement battery is nongenuine, cannot be verified, has been modified, or has not been properly linked to the device after repair. Some newer diagnostic-compatible aftermarket batteries, including products sold by REWA, are designed to complete Apple's Repair Assistant process.

Is a used-pull iPhone battery safe to install?

A used-pull battery can be a reasonable replacement if it is genuine, undamaged, properly tested, and still has sufficient capacity, but being an original Apple part does not make it equivalent to a new battery. On supported models, particularly iPhone 15 and later with iOS 18 or later, Apple allows a genuine battery previously installed in another iPhone of the same model to be reused and identifies it as Used in Parts and Service History. Its previous usage does not disappear: battery capacity, cycle count, and first-use history reflect the battery's actual life. So a battery sold at 90% health has already lost roughly 10% of its original maximum capacity. When buying a used-pull battery, check its health, cycle count, physical condition, testing history, and supplier warranty, and avoid batteries showing swelling, damage, or other signs of deterioration. 

Do third-party iPhone screens keep True Tone?

Some aftermarket iPhone screens can retain or restore True Tone, but it depends on the screen, repair method, iPhone model, and iOS version. Apple warns that True Tone may not work correctly with a nongenuine display because replacement displays may not have the same calibration and integration as an original Apple screen. Traditional aftermarket repair methods can involve transferring or programming display-related data, while newer diagnostic-compatible screens are designed to simplify the process. For example, REWA currently sells diagnostic-compatible screens that it says can complete Repair Assistant without an original display IC transplant, and some models do not require a separate True Tone restoration procedure. It is therefore inaccurate to say that every LCD or In-cell screen is physically incapable of supporting True Tone; compatibility should be checked for the exact replacement screen and iPhone model.

What is the difference between Soft OLED and Hard OLED iPhone screens?

The main difference between Soft OLED and Hard OLED is the substrate underneath the OLED panel. Soft OLED uses a flexible polyimide-based substrate, while Hard OLED uses a rigid glass substrate. Both are self-emitting OLED technologies, so both can produce deep blacks and high contrast without an LCD backlight. The flexible construction of Soft OLED makes it more tolerant of bending, frame flex, and installation stress, while rigid Hard OLED is generally more sensitive to uneven pressure or housing deformation and is commonly positioned as the more affordable aftermarket option. However, Soft OLED does not automatically guarantee better brightness, color accuracy, touch response, or overall quality a well-made Hard OLED can outperform a poor-quality Soft OLED, so the individual screen specification and supplier quality still matter.

The Summary in Three Sentences

For most people repairing a current flagship iPhone, Tier 3 Premium diagnostic-compatible parts from REWA or REPART hit the sweet spot: near-OEM display and battery performance, no iOS warnings, certified, and under warranty at a fraction of Apple's service price. Tier 1 Original parts are worth the premium only if you have AppleCare+, need enterprise compliance, or are preparing a device for resale at OEM condition. Tier 4 Budget aftermarket is acceptable only for low-value devices where function matters more than features expect degraded brightness, possible ghost touch, and persistent iOS notifications.

For iPhone 11 and higher ones, if you get your screen changed from a non-authorized repair service center,“Important Display Message” will appear.

As screen replacement is one of the most common repairs for iPhone, the price of Apple's official screen replacement is several times that of third-party repair parts, which makes consumers have to turn to third-party repair channels.

However, the non-genuine screen warning will inevitably appear after third-party screen repair. Third-party screen replacement generally offers OEM or aftermarket screen. For OEM screen, we can transfer the original IC to the new OEM screen, which can get rid of the non-genuine display alert. Unfortunately, this doesn’t apply to most aftermarket screens. After testing by our engineers, we select several aftermarket screen assemblies that support IC transfer to remove the warning message, ranging from iPhone 11 series to the latest iPhone 12.

Next, we will show you how to remove the warning message with the aftermarket iPhone 12 Pro screen. After third-party aftermarket screen replacement, a non-genuine display warning appears and True Tone disappears.

As the aftermarket screen only stores the touch and pop-up encryption data, we need to restore the True Tone firstly. Connect the original screen with the programmer to read the True Tone. Then connect the aftermarket screen with the programmer to write the True Tone.

After reading and writing, True Tone is restored on the aftermarket screen but there is still a warning message.

The next step is to transfer the IC. Pre-heat the flex cable with a hot air gun at 240 °C. Then apply some alcohol and carefully pry up the flex cable.

Insert a blade under the flex cable and apply high-temperature tape around the IC. With hot air gun at 240 °C and airflow 8 for about 6-8 seconds, we desolder the chip.

As the chip is removed, we apply some middle-temperature solder paste and paste flux. Flatten the bonding pads with soldering iron at 300 °C. Then remove adhesive with hot air gun at 300 °C. Clean the bonding pads with PCB cleaner.

Scrape away black adhesive on the edges. Once cleaned, apply some middle-temperature solder paste. Form the solder balls with hot air gun at 300 °C.

Next, we use the same method to remove the IC on the aftermarket screen. Please take protection measures thoroughly. As the soldering for aftermarket IC is different, we only need to use hot air gun at 100 °C for 5 seconds to desolder it.

Apply some paste flux to the bonding pads. Remove tin on the bonding pads with soldering iron at 320 °C. Clean the bonding pads with PCB cleaner.

It can be seen that the pins and solder joints are consistent with the original screen.

Then we install the original IC. Apply some paste flux. Solder the IC with hot air gun at 240 °C. After the screen cools, clean residue soldering paste with PCB cleaner.

Install the aftermarket screen. There is no non-genuine display warning and True Tone is restored. The display and touch also work fine.

As the technology becomes more and more mature, many third-party screens are not much worse than the original genuine screens. In terms of display effect, touch effect and price, the third-party screen replacements are much more cost-effective than Apple's original screen replacements. We not only provide aftermarket screens that support IC transfer to get rid of the warning message but also full set of tools and technical support. Other than that, we provide aftermarket screens without the IC to save you from the trouble of removing. If you are interested, please don’t hesitate to contact our account managers.

You will see “Important Display Message” on iPhone 11 and higher ones if you get your screen changed from a non-authorized Apple repair service center. 

The alert will initially be displayed on the lock screen within the first four days after the replacement. Then, the same message will appear in the settings menu for another 15 days. Subsequently, it can only be seen in the settings under "General" > "About".

If you want to know how to remove “Important Display Message”, please check out our YouTube channel.

Very much like some other artificial item, built-in lithium-ion batteries in an iPhone have a restricted life expectancy. In the end, they get worn out and quit displaying maximum performance, bringing about arbitrary rebooting and battery drain issues. In addition to that, worn-out batteries may likewise make the iPhone overheat.

When you get your battery replaced from a non-Authorized Apple service center, Apple begins showing a Genuine battery message alert on some iPhone models. In the event that you are getting an alarm on your iPhone about the genuine battery message and considering what it is, this guide is for you.

For what reason is Genuine/Important Message Alert Appearing on Your iPhone?

Apple has always been outstandingly worried about involving excellent parts in its gadgets. It’s a well-known fact that the Cupertino-based organization needs to have unlimited oversight of its gadgets, which practically rules out an autonomous fix. While this conduct can undoubtedly be alluded to as the work of art "Money Digging" strategy with which Apple is broadly related, we have consistently appreciated the tech goliath for going to additional lengths to keep clients from succumbing to non-genuine parts.

For this situation, in any case, Apple has chosen to show this message if the battery isn't changed by an approved Apple Service Center, and regardless of whether the battery is an authentic OEM battery of a similar quality as the one Apple uses. Forget OEM battery, assuming that you take 2 brand-new iPhone XR, for instance, and trade the batteries of the 2 devices on your own, you will begin receiving this message on BOTH the gadgets. The message isn't a sign on the nature of the battery or the sort. If essentially shows that the serial number of the replaced battery doesn't match the serial number put away in the settings of the gadget. At the point when an Authorized Service Center places in another battery, they utilize a unique programming to adjust the new serial number with the goal that your iPhone begins perceiving this substitution battery similar to possess. Since this product isn't accessible with any other individual but Apple, this message is something one needs to live with, at whatever point the battery is supplanted in specific models of iPhone.

On which iPhones does the Important Battery Alert Appear?

The genuine battery alert shows up on iPhone XS, iPhone XS Max, iPhone XR, iPhone 11, 11 Pro, 11 Pro Max, iPhone SE 2, iPhone 12, 12 Mini, 12 Pro, 12 Pro Max, 13, iPhone 13, 13 Mini, 13 Pro and 13 Pro Max. To be more exact, the battery health appears just on the 2018 iPhone models and higher ones.

The alert reads, "U Unable to verify this iPhone has a genuine Apple battery. Health information not available for this battery."

You may also see an extra message expressing that "Apple has updated the device information for this iPhone." It implies that the tech goliath has refreshed the gadget data for your iPhone for security investigation and service needs.

How Long does the Alert Exist on Your iPhone?

When Apple discovers the utilization of non-genuine battery parts on your iPhone, it appears the important battery message right on the lock screen as a clear warning. The message stays on the lock screen for the first 4 days and in the Settings for 15 days.

From that point forward, you can go to Settings > Battery > Battery Health to check the battery alert.

Does This Message Affect Your Ability to Use the iPhone?

No. Apple clearly expresses that the "Important Battery Message" doesn't influence your capacity to use your iPhone. As referenced over, the alert is simply to illuminate you that the replaced battery isn't perceived by the iPhone. It makes little difference to the performance of the battery. The sole disadvantage is that the battery health isn't visible in the Settings straightforwardly but can be checked by means of 3rd party Apps and software.