Stealth Dimmer v4: Troubleshooting

Problem Solution
Screen goes blank or has weird lines on it when sync wire is connected Make sure you have an authentic Division 6 Stealth Dimmer. Some imitations have a completely different wiring scheme and could cause your GBA to malfunction if connected using the diagrams on this site.
The chip is installed and the Afterburner lights up, but none of the buttons respond The chip may simply be locked. Try holding Select down for 5 seconds. If the chip unlocks, the Afterburner will blink twice and the buttons should start working
The Afterburner starts flashing a few seconds after the GBA is turned on This is an error code being generated by the built-in diagnostics. The number of flashes will tell you what to check:

1 Flash = A button shorted or connected incorrectly
2 Flashes = B button shorted or connected incorrectly
3 Flashes = Select button shorted or connected incorrectly
4 Flashes = SYNC wire not connected properly

Note: It is possible to have more than one error code.
One button seems to not work. For instance, the Afterburner can be made brighter but not darker Test the buttons using the built-in diagnostics. Turn the GBA off, hold the button down, then turn it back on. Keep holding the button for 5 seconds. If the button is connected correctly, the error code that corresponds to that button should be blinked out on the Afterburner. Test all 3 buttons in this manner. If one of them does not produce an error code, check the wiring to this button.

1 Flash = A button held down
2 Flashes = B button held down
3 Flashes = Select button held down
The chip is installed but appears to be totally dead Try holding down Select to lock/unlock the chip, or try the button test procedure listed above. If any of these work then you know that the chip is good and has power, and the Afterburner is working and properly connected. If they don't work, double-check all your connections. Most Stealth Dimmer problems stem from soldering/connection issues. You may also want to test the Afterburner itself by connecting it directly to the GBA as directed in the Afterburner manual.
The chip appears to be working, but its behavior is erratic or the controls don't work the way they are supposed to. Make sure you have an authentic Division 6 Stealth Dimmer. Imitation chips often have different connection requirements and won't function properly when connected using the diagrams on this site.
Dimming works fine, but every time Select is pressed, the light turns on or off. Make sure the chip you installed is a v4 and not an SP.