A - Back Case
Concerning the reconditioning in general, all screws and other holding plates must be present, all screws in the right place. No traces of glue on the screen or chassis should be present. The markings and colours shown on the device must comply with the manufacturer's graphic charter.
Chassis with even slight twist/twist should be discarded from sale.
- It is recommended to avoid replacing the chassis as much as possible because a non-original chassis will be subject to various problems:
- Since the torsion measurement is not carried out during the production of "copy" of frames, the torsion resistance is low or even non-existent depending on the quality of the "copy".
- The aluminium alloys used in the chassis were not chosen in terms of strength but in terms of economy. This leads to poor heat loss, internal electrical insulation, and also and especially to low or even no resistance to impact, and or immersion (even if the refurbished equipment is no longer certified waterproof).
- In order to sell a refurbished device on the Back Market, the assembly must be compliant (the screen must not extend beyond the chassis even slightly). This is practically impossible on a "copy".
B - Screen
We recommend that you carry out a complete test (manual + test software). This will allow you to perform a complete scan of the screen. You can also press and hold an application to move it to the four corners of the screen and from above perform a grid to test the touchlines do it in both directions (switch screen sideways).
We remind you that the resistance of the screen is closely related to the thickness of the touch screen used to recondition the screen. If the glass meets low impact resistance, the life of the unit is biased.
On the same basis there are 3 types of touch screen quality:
2 kg max. pressure (drop less than 50 cm = crack)
3 max. pressure (drop less than 60-80 cm = crack)
12 max. pressure (drop less than 1m-1m40 = crack)
Gorilla Glass is present on more than 900 smartphone models, representing 6 billion devices from 45 different manufacturers, including Samsung, Huawei, Apple and Xiaomi.
The backlighting must not show even slight traces of reconditioning of the screen, such as traces of cutter blades. You should also check for any white spots resulting from dust between the LCD and touch panel.
The backlight must not show traces of dust on a white background (blank point symptom).
As the screen is in several parts (lcd/tactile/backlight/chassis), it is important to check that the alignment of its different parts is correct. There must be no unplanned gap/spacing at this location.
For the refurbisher, it is necessary to check the torsional resistance as well as the rigidity of the different layers composing the screen.
There are different types of tablecloths depending on the quality of the screen (strength/flexibility). The quality must be equivalent to that of the original screen for better durability.
The exterior color of the screen must be in accordance with the original color.
It is important to ensure that the glue between the screen and the screen frame (bezel) is of good quality. You can, therefore, perform tests on a significant sample of the screen batch that will be used for future reconditioning of the devices.
At the same time, we advise you to check the plastic resistance of the screen bezel. Indeed, if a weakness persists, the screen will detach from the chassis and cause a service opening even if the screen is still functional.
The alignment between the facetime camera and the location provided for this purpose must be perfect. When sourcing your screens, make sure that the additional transparent plastic part to "fix" the lens is present. The same applies to the proximity sensor.
For cleaning, a simple antibacterial treatment on the screen is sufficient. Also remember to check that the lower and upper screens of the screen are free of dust and other contaminants.
C - Batterie
Batteries must be tested upon receipt of stock in two ways:
- Perform a first diagnosis with test software such as Blancco, Cellebrite, Picasoft or Phone Check.
- Perform a physical test (Number of load cycles, Production date, Percentage of wear and tear).
It is important to store/transport the batteries in a dry place and away from temperature fluctuations. Above 45°C, the internal pressure of the battery is at its maximum and may implode or degas.
We recommend that you prepare a hermetic container in a separate room for used batteries.
These tips are very important since the battery of a device sold on the Back Market must have a minimum capacity of 80%.
The battery must be charged at least 50% when the end customer receives his device, so it is advisable to work on a stock rotation (PEPS) allowing the easy management of the charging problem. Equipping yourself with one or more load banks can be a solution if you sell a large quantity of equipment at the same time.
D - Charging connector
It is imperative to ensure that the charging connector is clean to avoid any presence of "lint" or other accumulation.
The charging connector must be compatible, this means that no error messages saying that the cable is not recognized should appear. It must be possible to load in both directions.
When replacing the charging connector, use only original parts as the "copy" charging connectors tend to overheat and can cause the device (battery or motherboard) to fail. A "copy" charging connector may also not work with an original cable.