I repaired my Xiaomi Mi 9T Pro’s charging port, broken rear glass, and dying battery for R780.24 — and it is now like new.
The Xiaomi Mi 9T Pro, also known as a Redmi K20 Pro, was sitting in my drawer after I upgraded to a Samsung S22+.
The Xiaomi was still in working order, but I dropped it a few times, which caused the rear glass to break.
It had a few sharp edges, but it helped to stick it in a silicone case.
The phone’s battery was also deteriorating. Accubattery indicated an actual capacity of 2,923 mAh, significantly lower than the original 4,000 mAh.
To make matters worse, it was a struggle to charge the phone. The USB C port was worn out to the point where only specific cables held at the right angles would work.
The phone has outstanding specs for a device released in 2019, with a Snapdragon 855 and 6 GB of RAM.
The device also sports a 48MP camera that takes great pictures, has a dual SIM, and supports LTE-A.
Even with these great specs, the charging port made it unpleasant to use.
I looked into replacements for the broken parts and found a new glass back panel and the circuit with the USB port on it for R381.
It looked like a good deal to repair a high-end smartphone and save it from becoming e-waste.
While waiting for the new components, we found a new battery on Aliexpress for R366.29 after shipping.
I bought the components with cryptocurrency, and the glass back panel and the circuit arrived two weeks later.
However, the battery took almost three months, and it had to be collected from a Post Office for an additional R32.95 fee.
The battery included handy tools to open the back of the device, including a suction cup, two prying tools, two picks, and two small screwdrivers.
It was time to fix the Xiaomi Mi 9T Pro.
I started by removing the old rear glass, which was pretty easy as it was broken already.
Pulling with the suction cup while working our way through the glue with a pick had it off in no time, revealing the insides.
If the rear panel were still in good condition, a heat gun would have helped soften the glue during this step.
With holes in the phone’s rear, a lot of dirt had made its way inside. I cleaned it using alcohol pads to prevent it from getting in any connectors we had to remove.
I was ready to start dismantling the inside.
I first removed the screws holding the protective plates over the electronics.
Watching a video where someone else disassembles the same device helped to point out easy-to-miss screws and the order of removing parts.
After removing the plates, we could disconnect the battery connector and other connectors on the bottom board that we wanted to replace.
These connectors are easily lifted using one of the prying tools. However, you should be very careful not to break an entire plug off the boards.
The old battery was trivially removed using the pull tabs. We could slot the new one in using the same adhesive that remained attached to the rest of the phone.
The replacement bottom board was not identical to the original. It seemed to miss additional ground connectors, but we went ahead with the swap anyway.
The rest of the components went in the same way we removed them, with all the plugs clicking into place with minimal force.
We checked the device worked before closing it back up, and it powered on immediately with the battery around 40%.
The new charging port also worked perfectly, including Quick Charge.
Before glueing on the new rear panel, we went around the back of the device again with an alcohol wipe to make sure all the glue surfaces were clean.
It helped to ensure the panel would stick properly.
The back panel was carefully positioned and pressed down all around the outside of the device where the pre-applied glue was located.
The device now functions as a new phone. Only the wear and tear on the metal frame makes it obvious this Mi 9T Pro is secondhand.
Accubattery estimates an actual battery capacity of 3479 mAh. It is not perfect, but it should give the device some extra life.
I performed a few charging cycles and did stress tests while monitoring for any problems.
Seven hours of screen-on time only reduced the battery to 40% from a full charge.
This phone is now ready to be used again, charging easily, providing good battery life, and no longer hurting the user because of a cracked back cover.