Why test a part that was tested at the factory
Every screen and battery we sell is tested before it ships. It then spends two to four weeks in a parcel, passes through two customs checks and lands on a bench where it is handled by somebody in a hurry. Testing on arrival takes two minutes per part and catches the dead-on-arrival units before they cost you a customer visit and an hour of labour. It also settles any claim quickly: a part reported within the inspection window, with a tester photo, is replaced without argument.
The equipment on this page is in Programmers & Testers.
Testing screens
Option 1: a display tester
A dedicated tester such as the JCID V15PM is a small box with a model-specific flex for each iPhone from X to 15 Pro Max. The screen connects to the flex, not to a phone, and the tester drives it with test patterns: solid white, black, red, green, blue, a grid for touch and a grey ramp for banding. It also reads the display chip, so you can confirm True Tone data and the panel’s serial and type before you fit it. For a shop that receives screens in packs of ten, this is the fastest route: 30 seconds per screen, no phone needed.
Option 2: a test flex on a donor phone
A display tester flex cable (we stock the DL series per model) is an extension flex that sits between the phone’s connector and the screen, so you can connect a screen without seating it in the frame. It is the budget route and the one to use for models newer than a tester supports. Disconnect the donor phone’s battery before plugging in each screen, then reconnect and power on; hot-plugging a display is how test benches kill screens.
What to check on every screen
- White screen: dead pixels, dust under the glass, yellow or pink tint at the edges, backlight bleed on LCD.
- Black screen in a dim room: light leaks and grey blacks (expected on Incell, a defect on OLED).
- Touch grid: drag across the full surface and the corners; a strip with no response means a damaged touch flex.
- Brightness at minimum and maximum, and a grey ramp for banding or flicker.
- Earpiece and sensor flex, if the screen came with them attached.
- Chip read: True Tone data present, serial readable. On Refurbished Original screens, confirm the panel model matches the listing.
Testing batteries
Battery tester
The RELIFE TB-06 Pro connects to the battery flex and reads what the phone would read: voltage, design and actual capacity, cycle count, temperature and serial. On an Original Chip pack the cycle count should be 0 and actual capacity within a few percent of design. On a JCID pre-programmed pack the values are whatever was written; use the JCID programmer to read and set them. A pack showing a wrong serial or a cycle count that does not match the listing is a packing error; report it before installing.
Charging board
A board like the Mega-Idea iCharger 4.0 connects to the flex connector and charges the cell outside the phone, showing voltage and current. Use it to wake up a cell that arrived at storage voltage (around 3.7 to 3.8 V) and to check that it takes a charge. A cell that stays below 3.0 V or will not take current is dead. Cells are shipped partly charged by regulation; a low reading on arrival is normal, a reading of zero is not.
Bare cells
For Cell Only batteries check the open-circuit voltage with a multimeter on the tabs, inspect the tabs for cracks, and check the cell thickness against the bay before welding. A cell that is 0.3 mm thicker than the original presses on the screen from behind and shows as a bright spot on an LCD.
Testing flex cables and small parts
- Charging port flex: plug into the donor phone, connect a USB meter and confirm charge current, then make a call to test the microphone.
- Power and volume flex: test every button before the frame goes back on; a missing click is a bent dome, not a software problem.
- Cameras: open the camera app on the donor phone, switch between lenses, check focus and OIS by tapping the phone gently while recording.
- Face ID flex and front sensor flex: these are tested only in the phone they belong to; a JCID V1S can read the dot projector data to confirm the chip is alive.
Reading data with JCID and DL
A JCID programmer (V1SE, V1S Plus or V1S Pro) reads the display chip, the battery chip, the Face ID flex and camera flexes. Beyond pass/fail it tells you the panel type (which separates an original pull from an aftermarket panel with transferred data) and lets you write True Tone to a replacement. The DL tester flexes are the passive side of the same bench: they bring the screen to the phone or tester so the data can be read before the screen is seated. The combination lets you inspect, read and program a screen without a single screw.
Keep a log
Write the result on the part’s bag: date, tester, pass or the defect. It takes ten seconds and makes warranty claims, stock rotation and the occasional argument with a technician much shorter. Parts with a defect go back in the box with the photo; parts that pass go to the shelf by model, which is also how they are listed under iPhone Parts.
Safety
- Disconnect the donor phone’s battery before each screen swap on the bench.
- Do not test batteries on a metal surface; use a silicone mat.
- Bare cells: tape the tabs after testing so they cannot short in the drawer.
FAQ
Do I need a dedicated screen tester or will a phone do?
A phone with a test flex works for low volume. A tester is faster, reads the chip, and does not risk a working phone. Most shops over ten screens a week buy one.
Why does a new battery show 90 percent health?
On an Original Chip pack it should show 100. A lower figure means a used chip or a cell that has lost capacity in storage; report it. On a programmed pack, the figure is what was written.
What is the inspection window for a claim?
Defects found on arrival should be reported within the period stated in our terms, with the tester reading or a photo. Parts that have been installed are handled under the warranty terms on the product page.
Can the tester tell an Original from a Soft OLED?
It reads the panel type from the chip and the tester image shows the bezel and colour difference. Together they identify the grade in most cases.