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.

Battery repair is a common repair case every day. Today we're going to share with you the steps and details we need to pay attention to when replacing the battery cell.

Firstly, we use a clamp fixture to separate the phone

Remove the battery

Then we need to solder the BMS board of the original battery to the new battery

Remove the protective tape on the BMS board

Disconnect the cathode and anode of the battery with a pair of scissors

Please do not break the flex cable

Remove the original battery BMS board

Pry apart the anode tab and cathode tab

Place them on the welding clamp fixture

Put the battery cell with nickel-plated tabs onto the welding clamp fixture\

The cathode tab and anode tab are settled under the BMS board

Please align the anode and cathode respectively

Solder with the Spot Welder

Note that one end of the spot welding pen is placed on the conductor material (copper)

The other end is placed at the point to be soldered

Folder well the tabs after soldering

Apply the protection tape

Put on the protection bracket

Wrap another layer of protection tape on the outside

Connect the programmer to the laptop

Open the software

Click reading the battery data

Select the data that needs to be rewritten

Recalibrate the cycle times and battery efficiency

Click writing, and then the recovery

Disconnect the cable

Connect the power cable to turn on the phone

“Important battery message” is displayed

Turn off the phone and take out the battery

We install the new battery

It will be verified automatically by the system

There is no “Important battery message” now

A bitmap is the primary repair software in the motherboard repairing area, which can help us search out the issue point. As you all know, REFOX Bitmap was publicly released in 2019, it covers 236 countries and areas, and more than 110,000 users have joined us. The new subscribed version has been updated with more functions and rich content compared to the old version. Now let's explore it.

Firstly, we can download the app on REFOX's official website: https://www.refoxteam.com/download-bitmap

After registration, we need to sign up, and if you are an old user, you can use the original account to log in. There are three different packages we can choose from REFOX Bitmap. You will receive an activated number after the payment.

REFOX Bitmap Subscribed Version supports more than 2000 models, including MacBook, iPhone, and Android. This software has abundant diagram types covering bitmap, schematic, components distribution, and circuit block diagram.

Let's move on to the interface of the software. Its interface is straightforward with full features. REFOX Bitmap is updated monthly, and we can check out the update log below.

Split View&Multi View

Here's the double view function. It's able to check the bitmap and schematic at the same time while repairing, which is convenient and efficient for your work. What if you work for various motherboard types, and you hope to check them out one by one? No worries, REFOX Bitmap offers you multi-page at a time. It can switch to different pages in the same interface, making it easier to check out your project.

Save to Your Favourites

You can save the bitmap you use very often or the necessary ones into the favorites, making it easy to find it next time. The favorite folder is on the left side of the interface.

Quick Search

If you want to locate a bitmap, input the motherboard name or number to find the bitmap you wish. This function can help us easily locate the bitmap quickly.

Color Template Setting

Based on maintenance needs and usage habits, you can set the color template to a particular mode. It's easy to get started.

Case Sharing and Feedback

If you have any problems when using the software, you can upload your feedback at any time. And it's encouraged that subscribers could share their repair case with REFOX Bitmap Team. In this way, more and more users will benefit from your sharing and good advice for REFOX Team to make it better.

Lastly, it's time to update your REFOX bitmap version for the old users. And it's a good chance for the maintenance to try this advanced software, which will be your best assistant for your repair career.

Some people may come across such problems when using the iPhone with Face ID - iPhone continues to prompt "Move a Little Lower/Higher". But no matter how you move, you can’t reset the Face ID. You can try the following methods to solve the problem:

1. Restart your device

iPhone X and later model restart method: please press the side button and any volume button until the slider is displayed, then slide the slider to shut down; then press the side button until the Apple logo appears.

If it is a problem with software or temporary system failure, it is generally resolved after reboot.

2. Take off the film or check if there is dirt

Please check if there is a stain or occlusion near the front camera, and clean it with a lift.

3. Check if the device is water damaged

If the device has touched or fallen into the water before the problem occurs, it may cause the Face ID not working. Please bring your device to Apple after-sales.

Understand if the iPhone is water damaged by the indicator:

Most iPhones are equipped with an LCI that can be seen from the outside. The LCI can tell if the device is not exposed to a liquid or aqueous liquid. Normally, the indicator should be white or silver. But after contacting the water or aqueous liquid, it will become red.

To determine if the LCI of your device touches the liquid, you can refer to the following picture to help you see the LCI. Please use the lamp magnifying glass, adjust the angle of the light or device until you can see LCI.

4. Update the system

If the device is not accidentally water damaged, you can try to update the system to the latest version. If the problem is still unable to resolve, you should send your device for repair in no time.

If you don't want the content recorded in the iPhone's memo to be easily viewed by others, you can set a password for the memo or unlock the memo through face ID.

Notes before use:

1. It is recommended to create a password that is easy to remember and set a password prompt for yourself. Make sure you can remember the password, otherwise you may not be able to view the locked memo.

2. If you access your iCloud memo on multiple Apple devices, you will use the same memo password to lock and unlock all memos.

3.Enabling Face ID or Touch ID as a memo password will add the encryption key used to the encryption memo to your key chain, which can be accessed through your device password. This means that anyone who has your device lock screen password can access your lock memo. To maximize security, you can choose not to enable Face ID or Touch ID as a memo password.

Set the memo password and set the Face ID unlock:

1. Open the memo to be locked, tap "Operation" button or "..." button in the upper right corner, then tap "Lock Memo".

2. Enter your password and be sure to set your password prompt for yourself. At this point, you can choose to access the locked memo through the Face ID and tap "Finish" to save.

If you have already set a password, you need to change your password or set it. You can go to the iPhone "Settings" - "Memo" to make changes.

After locking the memo, it will automatically be protected by the password on all your devices. If you use a Face ID or Touch ID on other devices to unlock a memo, you must enter a password. Then enable the Face ID or Touch ID on the device used.

Recently we got many messages about Face ID not available after screen replacement from our clients, which surprised our technicians greatly. Since the screen replacing would not affect face ID function at all according to our practical verification. However, REWA has done some further researches and will share you the detailed analysis and solution for iPhone X face ID failure caused by damage of flex cable after repair here.

How does face ID work?

First, let’s understand how face ID works. The whole functional area is dubbed the “TrueDepth camera system”, which is made up of flood illuminator, infrared camera, front camera, dot projector, proximity sensor, ambient light sensor, speaker and microphone. Speaking of which, have you read iPhone 8/X Ambient Light Sensor Issues ? Every time you glance at your iPhone X, the flood illuminator detects your face with infrared light and forms an image. Then the dot projector will project out over 30,000 invisible infrared dots over your face to create a 3D map. Last, the infrared camera reads this map and sends the data to neural networks to create a mathematical model of your face. Your iPhone X will check that mathematical model against the one that you've set up and stored on your device to see if it's a match, and if it is, it will unlock your phone.

How do we repair?

According to the description, this iPhone X was dropped once. However, the face ID is in normal status. It fails to work until a replacement of screen assembly. With all the knowledge, we begin our repair.

Power on the phone and it shows “unable to activate Face ID on this iPhone” . So we resort to resetting face ID. Go to Settings > Face ID & Passcode > Reset Face ID. We get the message “Face ID is Not Available, try setting up Face ID later” . Our initial judgment is that the unavailable Face ID might be caused by misoperation in the screen replacing process. Therefore, next thing we do is to check flex cables that are related to Face ID.

Disassemble the phone. And check the Infrared camera and dot projector module under Microscope first. Nothing goes wrong. Then move to the Flood illuminator module on the earpiece speaker assembly. Check the connector and flex cables carefully. Still, nothing goes wrong.

Then remove screws. And detach the earpiece speaker and front sensor assembly from the phone. Be careful not to damage flex cables in the process since the Flood illuminator module is bonded to glass lens with double-sided tape. We can see clearly that the flex cable where locates the Flood illuminator module is fractured at the edge.

Since the Flood illuminator module is an essential part for Face ID circuit, damage of the flex cable can result in not working of it, which can absolutely affect normal working of Face ID. Also, as flex cable repair is difficult, we can solder the Flood illuminator module to a new flex cable. To replace with a new flex cable, we need to separate the earpiece speaker and the ambient light sensor module from the earpiece speaker and front sensor assembly first. Heating with Soldering Iron, the ear speaker was separated successfully. Then, secure the flex cable in the place with High-Temperature Protective Tape for further separating the ambient light sensor module flex cable. Soldering Iron and Hot Air Gun are required to remove this flex cable. Once done, remove excess tins on the flex cable with Soldering Iron and clean with PCB Cleaner.

Now the fractured flex cable is separated completely. Next thing we do is to replace with a new flex cable. Remove the Flood illuminator module on the flex cable first. Prepare a new flex cable. Apply some Paste Flux to the bonding pad. Align the Flood illuminator module in place with the new flex cable. Be careful with the direction. Then solder with Hot Air Gun. Remove residual glue on the module afterward.

The repair part is almost over right the moment. Next thing we need to do is to re-solder the ambient light sensor module and earpiece speaker. However, the soldering of the ambient light sensor is the most difficult part of this repair. Whatever, let’s do it. Apply some Paste Flux to the bonding pad of ambient light sensor module. Then apply tins to the bonding pad with Soldering Iron . Clean with PCB Cleaner. Apply some Paste Flux to the bonding pad again. Get the detached ambient light sensor module flex cable in position. Secure the flex cable with one specific position soldered by Soldering Iron with curved nozzle first. Then use Soldering Iron with cutter nozzle to complete the remaining soldering process. Clean with PCB Cleaner afterwards. Now we need to solder the earpiece speaker back to flex cable.

It’s time to get the earpiece speaker and front sensor assembly assembled to the display assembly. Re-assemble the phone and test. Press power button to power on. Go to Settings > Face ID & Passcode > Set up Face ID . Face ID can be set up successfully. Press the power button to lock the screen. Press the power button again. The screen lights up. Glance at the iPhone X. The screen can be unlocked automatically. Fault cleared.

questions about iPhone X Face ID Not Working After Repairing Tutorial, welcome to comment below or ask a question on ASK Forums .

Click below if you are interested in the Tools & Spare Parts used in the video. For more details and latest price please feel free to contact sales@rewatechnology.com

* Integrated Mobile Phone Repair Platform

* Tri-wing Screwdriver - Type 2

* Straight Tweezer - Type 3

* 4x Optical Microscope - KS7045

* PCB Cleaner - 250ml

* BGA Strip Flux Soldering Paste

* Anti-static Plastic Pry Bar

* Heat-resisting Adhesive Tape - 5.0mm

* 100g Solder Wire - Type 1

* iPhone X Replacement Parts

Visit REWA  online shop  for more parts and tools.

I wanna learn basic knowledge about iPhone motherboard, master iPhone micro-soldering techniques, understand the work-flow of different iPhone circuits, master troubleshooting processes of different iPhone issues, and learn detailed screen/back glass refurbishing steps——You can visit REWA Academy.