Based on display technology, common screen assembly can be divided into OLED and LCD. According to different structures of the touch panel, the screen assembly can be divided into incell, oncell and outcell.

The biggest difference is the position of the touch panel. Incell's touch panel is embedded in the glass substrate, oncell is above the glass substrate and under the polarizer, while outcell is above the polarizer and under the glass lens.

Different iPhone Screen Assembly Structures

incell-LCD

G+G/G+F-LCD

G+F-OLED

Oncell-OLED

A+ iPhone X Screen Assembly

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.

There are various kinds of iPhone replacement screen with uneven quality, which makes many consumers confused while placing orders.

According to different structures of the touch panel, the screen assembly can be divided into incell, oncell and outcell. The biggest difference is the position of the touch panel. Incell's touch panel is embedded in the glass substrate, oncell is above the glass substrate and under the polarizer, while outcell is above the polarizer and under the glass lens.

It is widely acknowledged that incell is the best screen assembly. However, that’s not entirely true. In this article, we will focus on comparing incell with outcell to see if incell is necessarily better than outcell.

OEM screens are undoubtedly the best option for iPhone screen replacement. OEM screen assemblies of iPhone X and higher ones all feature outcell structure.

The difference between outcell and incell is their touch stucture. The overall effect of the screen has to be determined by resolution, brightness, color gamut, backlight, etc.

If the outcell is not working, you can just replace the touch panel. Since incell's touch panel is embedded in the glass substrate, the screen assembly might be scrapped if the incell is not working.

For outcell of iPhone X and iPhone 11, the camera ring is integrated with the bezel, which increases accuracy and fixes Face ID not working for some users after installation.

To sum up, incell is not necessarily better than outcell. We have to look into every factor while selecting iPhone replacement screen besides the structure. Even Apple recognizes outcell as it uses it on iPhone X and higher ones. Furthermore, because of its structure, outcell is more repairable than incell and some outcells have included integrated parts to bring convenient installation.

Apple's iPhone 13 Pro is the first iPhone with 1TB of storage. The 1TB version costs $500 more than the 128GB version. That’s a lot of money for the general consumers. In this video, REWA LAB will show you how to upgrade 128 GB iPhone 13 Pro to 1TB. At the end of the video, we will share the cost and the pros & cons of the storage upgrade.

The capacity of the iPhone 13 Pro is 128 GB. ProRes capture of the 128 GB iPhone 13 Pro is supported for up to 30fps at 1080P.

Then we turn off the phone. Disconnect the battery and remove the display. Protect the front camera module with specialized tape.

Take the motherboard out. Peel off foam and dissipation tape on the motherboard. The NAND is right under the A15 tape. To avoid potential damage, apply high-temperature tape around the NAND.

Remove corner adhesive with hot air gun at 330 °C. After the corner adhesive is removed, heat the NAND with hot air gun at 420 °C. Pry up the NAND gently with a pry blade.The NAND of iPhone 13 series is not locked as the iPhone 12 series. The NAND can be replaced without writing the original data.

Get a 1TB NAND. The 1 TB NAND is much thicker than the 128 GB.

Apply some middle-temperature solder paste to the bonding pads. Clean the bonding pads with soldering iron at 380 °C. Keep cleaning the bonding pads with solder wick. Clean the adhesive on the bonding pads with hot air gun at 330 °C.

The next step is to clean the bonding pads with PCB Cleaner. Once the bonding pads are clean, we need to reball the 1TB NAND. Align the reballing stencil and apply some middle-temperature solder paste. Heat with hot air gun to form the solder balls.

Next, we need to solder the new NAND. Apply some paste flux to the bonding pads. Put the NAND in position. Solder with hot air gun at 380 °C.

Put back the foam and dissipation tape. Then install the motherboard and the display. Connect the phone with computer to flash. After flashing, we activate the iPhone. The storage has been successfully upgraded to 1 TB. ProRes capture is supported for up to 30fps at 4K.

If you want to upgrade your iPhone 13 Pro, a 1TB NAND costs around 100 USD. Excluding labor cost and others, the cost of storage upgrade can be much cheaper than a brand-new 1TB device. However, you will lose warranty for devices under coverage if you choose to upgrade storage. The value of the phone will decrease after storage upgrade. In addition, storage upgrade can have certain risks and is demanding for the repair technicians. Improper operations may lead to not turning on, running slow, etc..

Provided your budget is enough, we recommend that you choose the model that fits your storage needs. Please resort to a reputable repair service center if you want storage upgrade for your device.

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.

Apple has encrypted the battery of iPhone XS and models above. Once you replace the battery, you will get the “Important Battery Message” and “Service” message. To make matters worse, the cycle count of the new battery will show the cycle count of the original battery. Especially the battery data of iPhone 11 series and iPhone 12 series still can’t be accessed. It has been verified by technicians that the “Important Battery Message” will show up after you put in an aftermarket battery or a genuine Apple battery. You can only avoid the problem by letting Apple Stores or Apple Authorized Service Providers replace your battery.

To solve the problem, REWA LAB has verified the latest solution. Today we will share solutions concerning iPhone XS series, iPhone 11 series and iPhone 12 series.

First of all, we will introduce the structure of the battery. The battery can be roughly divided into two parts – BMS board and battery cell. The battery management system board mainly serves as a protection board but also saves battery data. The battery cell is where the power is stored.

Taking iPhone XS for example, we need to prepare a battery data corrector and a new battery cell that can be an original one or an aftermarket one. Disassemble the phone and remove the battery.

Then we need to solder the BMS board of the original battery to the new battery cell. Remove the protective tape on the BMS board. Please do not break the flex cable.

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

Remove the original battery BMS board. Please align the anode and cathode respectively.

Solder with the Spot Welder.

After soldering, install the BMS board. Apply the protection tape.

Since the BMS board is replaced and the battery is protected, the voltage can’t be measured. We need to activate the battery with a Direct Current Supply.

Connect the battery to the programmer. Click reading. Battery data on the BMS board can be seen.

Recalibrate the cycle times and battery efficiency.

Then we connect the display to the motherboard. Connect the power cable to turn on the phone. “Important Battery Message” is displayed.

Please be noted that you can only turn on the phone by a power cable. The above step takes advantage of bugs in iOS and is a very important step. Then we install the new battery. Go to “Settings” to view the battery health information. The maximum capacity is 100% and there is no “Important Battery Message”.

Different from iPhone XS series, the battery data of iPhone 11 series and iPhone 12 series is encrypted and cannot be accessed. That is to say, even if you replace with the original battery cell, the battery data still can’t be read. Worse still, you can’t correct the battery health and cycle count. Recently, REWA LAB has got the latest battery data corrector on the market. Through verification, the corrector can effectively remove the “Important Battery Message” of iPhone 11 series and iPhone 12 series. Next, we will share the operation process in detail by an iPhone 11 Pro.

Remove the BMS board of the original battery. Solder the BMS board to the new battery cell.

Install the BMS board. Activate the battery with a Direct Current Supply.

Because the data of iPhone 11 series can’t be directly read, we need a specialized PCB board to read the data. Install the PCB board to the battery.

Then connect the battery to the programmer. Click reading. Recalibrate the cycle times and battery efficiency.

Connect the power cable to turn on the phone. “Important Battery Message” is displayed.

Then we install the new battery. Go to “Settings” to view the battery health information. The maximum capacity is 100% and there is no “Important Battery Message”. This method is easy to operate with visible repair traces. REWA technicians are now trying to remove the. “Important battery message” of iPhone 11 series and iPhone 12 series without traces. That’s all for REWA LAB’s solutions to the “Important Battery Message” problem. With the development of repair technology and Apple’s continued attention, we believe that new solutions will come up. REWA LAB will keep on bringing the latest information and technology. Please stay tuned. You can buy all tools and supplies in this article on REWA shop. Please feel free to leave a comment on repair topics that you are interested in.

In the previous blog: What Should A Qualified Battery Actually Be , REWA explained when should a battery be replaced and what standards we applied towards battery replacements. Now we will demonstrate the detailed production process and test procedures. Top quality batteries come from excellent materials, advanced automation equipment, and strict inspection&test standards. In the top-level factories, phone battery is usually carried out on highly automated equipment, with top quality materials applied. However there are still many smaller manufacturers who use manual assemble methods or poor materials, that is why the batteries in the market vary greatly. What should a complete battery production process be?

Production Process

Battery appearance inspection is a common but easy way to inspect your phone batteries, but it does not always work, lacking precise values and results. Some battery failures are not so easy to spot with naked eyes. However, the strict test is necessary for the lithium batteries to ensure safety and quality. Here we will demonstrate the professional and complete test procedures. The test can be divided into three parts: Appearance Inspection, Basic Performance Test and Physical Performance Test.

Appearance Inspection

Appearance Inspection: breakage, paint loss, crack, corrosion, labeled data

Basic Test Methods and Procedures

Physical Performance Test Procedures Further physical performance tests are conducted in the extreme situations, so as to verify if the battery will bend, deform, fire and explode in the different simulative environments.

1. Low-Pressure High Altitude Simulation Test This procedure is to test the air transportation safety performance of the battery at a pressure under 11.6kPa. Result: After 360 minutes, all the samples perform normally, no fire or explosion. /The samples do not explode or catch fire.

2. Temp. & Humi. Test This test is to verify the temperature adaptability of battery, processed at an extreme temperature of 72±2℃ and -40±2℃. Batteries are stored for 6 hours at 72±2℃, then 6 hours at -40±2℃, for a total of 10 cycles. Result: After 10 cycles, all the samples perform normally. No bulge, fire or explosion./ The samples do not explode or catch fire

3. Vibration Test Vibration test is used to verify the battery anti-vibration performance during the transportation and usage. The test is a Sine Sweep: 7Hz – 200Hz, 15 min/sweep, 12 times, 3 hours in total Result: All the samples perform normally

4. Capacity Test This is to test the actual capacity of the battery Result: OEM is the top performer. AAA Grade and A Grade come second, and the values are very close. B grade batteries are much worse than the above 3 kinds.

5. Impact Test Impact test simulates the impacting and hitting of the battery. Apply 561.5cm/s2 acceleration impact to the battery to test if it will be crushed or distorted when overload. Result: B grade batteries have problems of bend and deformation. Other samples perform normally.

6. External Short Circuit Test This test simulates an external short circuit to the terminals of the cell or battery. When the temperature goes up to 55℃, turn on the switch to make it short circuit, then check the battery to see if it will explode. Result: After 2 hours standing, all the samples perform normally. No fire or explosion. /The samples do not explode or catch fire.

7. Drop Test The drop test is operated at a height of 1.2 meters to test the battery hardness and anti-deformation capability. Result: B grade batteries have problems of bend and deformation. Other samples perform normally.

8. Crush Test Each battery is applied with a crushing force of 1.3kN for 0.1s. After 30 minutes, check the battery to see if it will fire, explode or deform. Result: All the samples perform normally.

9. Thermal Abuse Test The purpose of abuse testing is to verify that the battery is not a danger to the user either by accidental or deliberate thermal abuse under any conceivable conditions of use. After the temperature rise for 26 minutes, hold at 130℃ for 10 minutes, check the battery to see if it will fire or explode Result: All the batteries have the problem of bulging, no fire or explosion

10. Burning Test The purpose of this procedure is to test the safety performance of the battery. Put the battery into the machine, ignite it to test if the battery will explode and if the ashes are in clumps. Result: After 30 minutes, batteries burned completely, no explosion, with clumpy ashes left

Every battery from REWA has to pass through rigorous basic performance and physical performance test, and only qualified products can be delivered to the warehouse. This is to ensure every battery you get is superior, safe and reliable.

Certifications

Our business has been founded on the belief “Quality Above ALL” for years. The batteries from REWA passed a series of international authoritative certifications, such as UL, CE, FCC etc..

From all the above test results and analysis, we can draw a conclusion that OEM, AAA and A grade batteries are much better and safer than the B grade. Now that there is a shortage of OEM batteries, the cost-effective AAA and A grade batteries undoubtedly become your first choice.Every battery from REWA has been rigorously tested. Our QC and technical team can offer the right solutions for your needs and advise the best but economical battery replacements. If you have any questions and demands, please feel free to contact us.

Custom packaging is available! Want to order our products? Please contact us:

PRE-SALES Skype: rewatech Email: service@rewa.tech

AFTER-SALES Skype: support-rewatech Email: support@rewatechnology.com

We have received an iPhone X motherboard from a customer. The customer says that the iPhone X battery is draining fast with an overheating issue. Battery draining fast is normally caused by battery degradation or motherboard current leakage. After battery replacement, the battery is still draining fast. It can be judged that the problem is induced by motherboard current leakage.

Next, we check the current by powering up the motherboard with a DC Power Supply. The motherboard has a current leakage of 186 mA. If the motherboard shows a current leakage after being powered up, we can measure the following power supply circuits to find the faulty part.

In the first place, we measure PP_BATT_VCC. The resistance value is normal.

Then we measure PP_VDD_Main. The resistance value is 29 which is relatively low. It indicates that there is a damaged component on PP_VDD_Main. Since the current is small, rosin detecting is unable to find the faulty part. Therefore, we need to use a thermal imager to find the faulty part.

Power up the PP_VDD_Main on the motherboard. There is no obvious change in the temperature. The faulty part is not on the surface layer of the motherboard.

Then we separate the motherboard for further testing. Put the motherboard on the Heating Platform to heat. When the temperature reaches 165 °C, separate the logic board from the signal board.

After the motherboard has cooled, we firstly measure PP_VDD_Main of the logic board. The resistance value is normal.

Then we measure PP_VDD_Main of the signal board. The resistance value is abnormal. So we can confirm that the faulty part is on the signal board.

Open bitmap to confirm the position of PP_VDD_Main. Keep checking the signal board with the Thermal Imager. There is still no obvious change in the temperature. Through the bitmap, we see that PP_VDD_Main also exists under the card reader.

The faulty part is most likely hidden under the card reader. Then we check the back of the signal board with the Thermal Imager. The temperature on the top left corner of the card reader has gone up greatly. We can confirm that the faulty part is on the card reader area.

Then we need to remove the card reader. Apply some Paste Flux to the bonding pad of the card reader. To protect the plastic part of the card reader, apply some low-temperature Solder Paste to neutralize the temperature of the bonding pad.

Next, use helical wind Hot Air Gun at 340 °C to heat the card reader. Try to pry up the card reader with a Pry Blade while heating. When the card reader becomes loose, remove the card reader.

Keep checking the card reader area with the Thermal Imager. The temperature of the card reader area shows significant change. Judging from the bitmap, the part that gets hot is the GSM. Then we need to replace the GSM.

Apply some Paste Flux. Remove the GSM with vertical wind Hot Air Gun at 340 °C. Apply some Paste Flux and middle-temperature Solder Paste to the bonding pad. This is to lower the temperature of the bonding pad.

Clean the bonding pad with Hot Air Gun and Solder Wick. Then clean the bonding pad with PCB Cleaner. Measure the resistance value of PP_VDD_Main.

The resistance value returns to normal. Then we install a known-good GSM. Apply some Paste Flux. Put the GSM in position. Solder with vertical wind Hot Air Gun at 320 °C.

After soldering, measure with multimeter again. The resistance value is normal.

Keep applying some low-temperature Solder Paste to the bonding pad of the card reader. Clean the bonding pad with Hot Air Gun and Solder Wick. Then clean the back bonding pad with Soldering Iron and Solder Wick.

Next, clean with PCB Cleaner. It can be seen that the pins are clean.

Then we install the card reader. Put the card reader in position.

Solder the back bonding pad to fix the card reader with the Soldering Iron. Flatten excessive tin with Solder Wick. Please do not remove the tin while dragging the solder wick. Clean the bonding pad with PCB Cleaner.

Then we recombine the motherboard. Put the signal board on the 165 °C Heating Platform to heat. Apply some Paste Flux to the bonding pad. Align the logic board with the signal board. When the temperature reaches 165 °C, detach the motherboard.

For better recombination, press two sides of the motherboard gently with tweezers.

Then we power up the motherboard for testing. The current is normal. Connect the screen to test. The boot current is also normal. The current leakage problem has been fixed.

An important step for iPhone refurbishment is to change the battery. After battery replacement, the original battery information is gone. The original information includes manufacturer name, date of manufacture, serial number, manufacturer number etc. The battery with non-original information will fail the testing software.

As you can see from the picture above, the reading value is not the same as the original factory default. Therefore, the battery doesn’t pass the testing software.

For enthusiasts, not being able to get all green signs from the testing software spells disaster for them. That is like getting a black spot on your white T-shirt. One flaw has them wondered if they buy a good quality product even if the flaw doesn’t really matter and will not affect the usage.

For sellers, if the product can pass the testing software, the product will have more to prove that it is close to the original one, which can be a solid selling point.

The good news is that REWA LAB recently found that original battery information can be written in the aftermarket battery after testing, which means that aftermarket battery with the original information can pass the testing software.

Below are our testing results.

It is obvious that TI battery performs best in the testing. TI battery with original battery information can pass the testing software for most iPhone models.

To successfully write the battery information, Qianli iCopy 2.1 Repair Programmer is needed. Besides transferring the original battery information, the programmer can also clear cycle life and modify battery efficiency.

Click here to buy high-quality batteries selected by REWA.

With the diffused application of Face ID on iPhone X - 11 series, Face ID failure also appears at a high frequency. As our previous Face ID teardown video   has introduced, Face ID can be easily damaged and hardly repaired. If the problem is related to the flex cable, then it’s simple. However, based on statistics of REWA chip-level motherboard repair service , Face ID failure is caused by damage of the Flood illuminator/Dot Projector in most cases, which can not be repaired.

Today, we want to share a case about ‘move iPhone a little lower/higher when setting up Face ID’ and show you how our technicians find out the fault in 3 minutes with the help of REWA exclusive repair tricks on Face ID troubleshooting. Let’s get started!

Face ID Not Working Malfunction

The phone keeps sending messages: ‘move iPhone a little lower/higher’ during the setting up process of Face ID. It means that Face ID cannot be set up successfully on the phone.

Why is my face id not available troubleshooting

Now, let’s find out the fault step by step.

Step 1 Test The Flood Illuminator

Based on REWA exclusive repair tricks, let's start with the Flood Illuminator. There are two important Face ID parts whose behavior relies on the support of the Flood Illuminator. In our daily repair work, we can test the Proximity Sensor and the Ambient Light Sensor to confirm whether the Flood Illunmunator is working normally.

Let’s make a phone call to confirm whether the Proximity Sensor is working. During the phone call, cover the top of the screen with one hand. We can see that the screen turns black immediately. Judging by this, the Proximity Sensor is working normally. 

Next, test the Ambient Light Sensor. Set the screen brightness to the lowest and then hold the phone under a bright light. With the screen getting brighter, we can confirm that the Ambient Light Sensor is also working normally. Judging by this, the Face ID failure is not caused by Flood Illuminator. 

Step 2 Test The Front Camera Parts

Let’s move on to the next step of face id not working - test the front camera parts.

Open the camera app and swipe to Portrait Mode. The background is not blurred, which is abnormal.

Step 3 Observing The Dot Projector

At the Portrait Mode, there is no flashing red light from the Dot Projector. But the Dot Projector should emit flashing red light in normal status. We can confirm now that the Dot Projector has malfunctioned. This is the fault that causes the Face ID to set up failure. And the problem cannot be fixed.

Tips

The three parts ( infrared camera, flood illuminator and dot projector) are paired to the phone. Damage of any one of them can cause Face ID failure and such an issue is irreparable.

Right now, Face ID failure has become a common problem in our daily repair work. Whether the problem you are dealing with can be repaired or not is really an important thing for repair technicians. Don’t worry! REWA exclusive repair tricks on face id not working can be a great reference for repair technicians to find out faulty positions and improve repair efficiency.For details of this case, please check out the YouTube Video below.

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?

REWA Academy is a platform that provides repair technique learning, practical demonstration, and idea-sharing for practitioners in the electronic repair industry.