Troubleshooting

TroubleShooting

General issues

• Sometimes, when turning on the F256K/Jr, I get greeted with this screen, from which nothing can happen. How do you resolve this and why does this happen?

  

  Microkernel boot screen

• Every time you are powering off and on your unit, the FPGA needs to reprogram itself and that takes time (i.e. Not Instantaneous). It's possible to have faulty loading because the power supply is not quite stable; the RTC that generates the reset is not aligned with the rest of the system. If you are doing a quick on and off, the capacitors are not empty enough to create a rising power rail so the reset can do its things. Unfortunately those are not ASICs, so nothing is instantaneous.

FNX4N4S issues

• Can't seem to make the gamepad work reliably, or one button press affects multiple buttons and triggers at once
• After the first batch of these in 2023, the cable changed to use a different wire color mapping, but were still wired by the same colors inside the FNX4N4S case. If you have a newer unit that matches the original wire color arrangement below, you might need to rewire them to match the later one. Continuity check the DIN9 vs CN1 connections to be sure.

@Cibee's wiring solution

FNX4N4S pins inside, marked CN1	DIN9 pins outside the cable, while facing the pins	original 2023 run wire colors	latest 2024-5 run wire colors
1	1	blue	blue
2	6	red	red
3	2	white	green
4	7	brown	brown
5	3	green	orange
6	8	purple	purple
7	4	orange	yellow
8	9	black	black
9	5	yellow	white

Inside the FNX4N4S adapter box with the top cover removed. CN1 is where the cable is soldered directly on the PCB.

Facing the pins of the DIN9 cable of the FNX4N4S adapter box, from the outside.