I ordered a replacement screen from the M5Stack store on Aliexpress.
New TFT display + bezel arrived 15 days later.
Installation was reasonably straight forward.
- Soldering iron - I'm using old faithful Jaycar Duratech TS-1554 20W/130W
- Solder - I'm using cheap 0.5mm Sn 63 / Pb 37 / Flux 1.2
- Flux - I use a pen
- T6 Torx screwdriver - I have one of these sets
- Remove bottom battery/breakout board
- 2x T6 Torx screws hold the PCB in place
- Slide speaker out (careful of it's thin wires - I broke mine)
- Slide PCB sideways and lift slightly. The display ribbon cable prevents it from being fully removed
- Push the display + bezel from behind to detach it from the case
- Remove the bezel from the broken TFT
- Rotate the PCB 45 degrees and remove from plastic shell, to avoid damaging it
- Flip TFT 90 degrees revealing its flexible cable
- Detach the TFT by applying a little flux + solder and gently prying while heating the pins with a soldering iron
- Apply flux to the solder pads and stroke each with a soldering iron to create a smooth finish. There should already be enough solder remaining, if not, add a tiny bit more and stroke smooth
- Place the new TFT over the pins and precisely hold in place with your thumb while applying power to check the display works
- Solder pin 1, check alignment and adjust if need be
- Solder the remaining pins. Get some bright light and a magnifying glass and make sure none of the pins are bridged. Or use continuity mode on your multimeter to check adjacent pins
- Insert the PCB + new TFT back into the plastic case, slide PCB sideways and attach Torx screws.
- I accidentally detached one of the speaker wires earlier, so with the new TFT flipped out of the way, resoldered the speaker wire.
- In doing so, I detached the other speaker wire! So I swapped both for new thinker wire, salvaged from a Dupont ribbon cable. The wire can't be too think as it needs to sit between the TFT and PCB.
- Reseat the speaker
- Sit the TFT in place and remove the protective cover (green tab) being careful not to touch it with your oily fingers
- Remove the sticker from the back of the bezel and insert the 3 plastic buttons
- Attach the bezel onto the plastic case and press firmly
- Plug in USB and boot
- Press 3 push buttons to cycle through RGB colours
- It works!