FiiO M3K

Native port status

Hardware summary

Known issues

• Very rarely, the LCD driver might be causing a hang when the screen turns on after being off.

• The DAC makes popping noises when changing frequency. Mostly occurs when switching to or from a frequency >= 96 KHz.

• The touchpad sometimes goes wonky on boot and won't respond properly to scrolling or button presses for the first few seconds. There's nothing that can really be done about this except artificially forcing Rockbox to wait longer in the splash screen so you can't see the problem.

• Scrolling might feel a bit off because the touchpad doesn't report coordinates linearly as it should. In particular the edges of the touchpad seem more sensitive than the middle, so scrolling in the middle of the pad requires a bigger motion than at the edges.

Internal images

PCB images:

Closeup of the PWM LED controller and the I2S DAC:

Screen assembly closeup:

Datasheets

• Ingenic X1000E (ftp link)
• ATO SOLUTION ATO25D1GA
• X-Powers AXP192
• SGMICRO SGM3122
• FocalTech FT6x36
• TRULY TFT240240-2-E (the LCD mentioned in Fiio/Ingenic's kernel source, not the same one used in this device)
• Sitronix ST7789V
• Sitronix ST7789S
• Asahi Kasei Microsystems AK4376A
• MEMSensing Microsystems MSM42A3722H9KR
• CYG Wayon WP3881

Disassembly instructions

• Hair dryer
• LCD screen repair plier tool with removable suction cups
• E6000 adhesive
• Precision Philips screwdrivers
• Plastic pry tool (the triangular type)
• A thin plastic card
• Xacto knife
• Kapton tape

1. Unscrew a suction cup from your plier tool, firmly adhere it to the upper back side of the device with the E6000 glue, let it sit for at least 14h. Be generous with the glue, you'll be able to cleanly remove them later before they harden completely. This is necessary because the aluminum back doesn't play nice with the suction cup, it slips off before you can exert enough force onto the front glass.
2. Heat up the front of the device until the aluminum frame is very hot to the touch. Immediately screw the glued suction cup back onto the plier tool, and you should be able to get enough grip to pull the screen off now. You must pull it apart from the LCD side (not the touch controls side) to avoid damaging the ribbon cables.
3. Detach the two ribbon cable connectors and remove the screen assembly. Beware that the touch controller ribbon cable has a sticky back, carefully peel it off the board with a tweezer. Hit it with a hair dryer if it's hard to remove, that'll hopefully soften the adhesive.
4. Take your triangular pry tool, use it to push up & warp the upper panel from the inside of the device, there's an aluminum overlay that you'll hopefully be able to separate with your xacto knife (the key here is to cut away the adhesive instead of prying). There will be two screws hidden under that overlay, remove them and you'll be able to side the entire inner tray out from the bottom side.
5. Peel off the black insulation tape on the board to reveal some test points, including UART. Put on some Kapton tape before you attach the screen to prevent the metal bracket from shorting anything out.
6. Remove the 6 screws from the plastic tray (one screw is smaller than the rest), and you can take the board out.
7. Heat up the board again from the front side and use a thin plastic card to slowly separate the battery from the board. The PCB bends pretty easily so be careful NOT to bend it in the process, I find gripping on the PCB on the long sides can reduce bending. After you detach and desolder the battery, the disassembly is now complete.