More used iPhones are being sold here in the UK, and the market is growing; however, buyers are now more tech savvy. Therefore, it has become imperative for the seller to check the most important functionality in a phone before selling it. The advantages are very clear, you will sell your iPhone quicker and end up selling it for a higher price. You do not need to be a technical expert to analyse or to check these following features.
1) LCD Screen
- Once the screen is on, just slide your finger right to left or vice-versa if the screen moves then it is in working order.
- Go to Settings>>>General>>>Accessibility>>>Assistive Touch, turn on the Assistive Touch, now you will see a grey square box, just move that box with your finger. If it moves all over the screen your LCD is okay.
- When the screen has a white background, look for any burn marks or white spots. These dots indicate some issues with the back-light not necessarily with the LCD.
2) Battery Health
Settings>>>Battery>>>Battery Health>>>Just click on it and you will see the Maximum Capacity left in the battery. You will generally see the message for replacement at 70%. However, we have noticed that any battery which is below 85% will not last for too long. So, it is advisable to get it replaced.

3) Back Casing Condition
When someone is looking for a used iPhone, they are very much interested knowing the condition of the back casing also known as housing. However, there is one common issue which can make your iPhone Dead, and that is, putting your phone in the back pocket. By doing this, the casing can get bended which has direct effects on the motherboard and consequently makes the phone dead. So please make sure you check that your iPhone is not bent.

4) Vibration / Mute Button
To check the mute button, simply move the button up and down by doing this you must feel some vibration. If you do not feel any vibration, either the mute button or (Taptic Engine) Vibrator Motor is not working.

5) Ringer
Settings>>>Sounds>>> Now you will see a blue horizontal line, by moving this with your finger you will activate the ringer. If it does not move, then unfortunately, you will not hear any sound or hear at a consistent volume for incoming calls.

6) Volume Button
Play any video and move the volume button up and down. If you think it is not working properly, just get the Volume Flex replaced.
7) Power Button
By pressing the power button, you will notice that the phone is turning on. If it does not turn on, please get it checked. Most of the iPhones have Mute, Power and Volume Buttons in one Flex Cable.

8) Home Button
To check the home button, just press on the button and the iPhone should come on. If it does not, there could be two reasons;
- The Home Button’s Flex has become loose.
- The Home Button has a short, meaning one of the small components is faulty.

9) Proximity Sensor
To check the proximity sensor, just make a call and cover the round dot next to the earpiece speaker. You will see that the screen has turned off. It means that the proximity sensor is working properly. However, if it is not functioning properly then it would have effect on battery life and the iPhone will become hot which is also not good for the motherboard and surely for the battery’s health. This sensor can be replaced easily by changing the Front Camera Flex Cable.
10) Earpiece Speaker
When someone calls you and you cannot hear them, it means that your earpiece speaker is faulty. It is a very easy fix and the part does not cost much.
11) Loudspeaker
When you are calling someone, and they cannot hear you or when you turn on your phone speaker and it does not work. It means that the Loud-Speaker has some issue. Therefore, it is the time to get the part replaced. Again, it is a very easy fix and does not cost a lot of money.
12) Touch ID
This feature is very important because it can change the selling price. Touch ID is used for the security of your device and ultimately data. You check the touch ID on your phone; Settings>>>Touch ID>>>Add a Fingerprint>>> Now place your finger on the button. If it commences the finger printing process, then it means that the Touch ID is working properly. On the other hand, if it moves to a different screen then unfortunately it has an issue.
The major reason for the Touch ID to not work is, the home button has been replaced or the back-metal plate has been changed or the flexes have been damaged. Unfortunately, there is no remedy for it. Therefore, it is imperative to get the screen replaced by a professional because it has direct impact on the selling price. Most of the time it reduces the value of the phone to half.
13) Front / Back Camera
Press the home or power button, turn on the camera, now simply see the front and back camera and they should have a clear view without any distortion or pixilation. If either of the cameras have any issue just get them replaced. Sometime the flex cables have become loose; therefore, it is better to get it checked.
14) Video Recording
In the camera feature, you have video recording option, if either of the cameras not functioning properly. Then unfortunately, this feature will not work as well.
15) WIFI
Settings>>>Wi-Fi>>>Choose a Network
If it is not working properly, you cannot enter your password, or it would not show the password enter page. Unfortunately, if it does not work, you will have to get Wi-Fi IC replaced and that could cost you a bit of money, depending on the model.
16) Bluetooth
Settings>>>Bluetooth>>>Enable
When you toggle the button and it turns green and then back to grey, it means that the feature is perfectly operational.
17) Call Test
Make a call and should get connected but for any reason, if it does not go through.
- Check with your network provider
- Check the Sim Card and the Sim Trey
- Get the Network IC checked and if required get it replaced
18) Ambient Light Sensor
It adjusts to the light; however, if it does not work you cannot change the screen light, or it would not adjust to the required light in each time. Reason why it would not work.
- Screen has been replaced
- Not so good quality screen glass has been used
- Sensor Flex Cable has become loosen
- Some glue or heavy colour has been used on the sensor point
19) Accelerometer
This feature is very important for some buyers because it helps to capture a nice photo or to make a beautiful video. It changes the landscape image to portrait and vice-versa. If it does not work, get the LCD Screen or the Touch IC checked.
20) Microphone
Connect a headphone to the Microphone Slot if you hear sound then it is all good. Otherwise, clean the microphone slot, or get the charging flex cable replaced, or change the Sound/Charging IC replaced.
21) FMIP
Settings>>>Apple ID>>>Select Your Device>>>Find My iPhone>>>Enable or Disable
22) GPS
Settings>>>Privacy>>>Location Services; Toggle on/off
Turn on Google Map, if it does not come on, please Toggle on/off the Location Services.
However, if you experience the same issue, please soft reset your iPhone. This could be a software issue.

23) Flashlight
Slide your finger from bottom to top and a new page will appear, turn on the Flashlight. If it does not work, reset your phone; Settings>>>General>>>Reset
However, if the problem persists, try a soft reset>>>Hold Power and Home and Volume UP/Down simultaneously for five to ten seconds. By doing this, your iPhone should start the process for Soft Reset. However, this method could be applied differently per iPhone model.
