The Q2 is recent enough that QIDI hasn’t published a long error code list for it yet, and this guide reflects that rather than padding it out. What follows is everything currently documented on QIDI’s wiki: one numbered fan error and one named leveling error state. For anything outside those two, the printer’s own diagnostic tool, covered at the end, is the better place to check.
The one numbered code listed is QDE_002_001, a cooling fan speed error. The screen shows a message along the lines of fan_name cooling fan speed 0 may be error. This almost always means the model cooling fan, the one that blows on freshly printed plastic, is physically obstructed, usually by the hotend’s white cable resting against or catching on it. The fix: check behind the print head and confirm the cable isn’t blocking the fan. Move it clear, then restart the printer to see whether the error clears.
The second documented issue isn’t a numbered code but a named state: leveling error or probe error, with two possible causes. One is mechanical, something hitting the Z-axis mounting hardware as the bed rises, visible when you home the printer and watch whether the bed contacts the Z mounts; if so, loosen the side panel and bed screws, shift the bed slightly right, and retighten. The other is a bed tilted more severely than auto-leveling can compensate for, which calls for manual bed calibration, covered separately in our calibration guide.
For anything else, the Q2 has a built-in diagnostic layer called the QDC, or QIDI Diagnostic Center, which surfaces notifications about the printer’s mechanical and hardware condition with a description and troubleshooting suggestions. Check it from the printer’s screen or the Fluidd interface for anything not covered here.
With only two conditions documented so far for the Q2, most issues that come up will trace back to either the fan obstruction or the leveling fault covered in the Q2 calibration guide. For routine care that helps prevent both, see the Q2 maintenance schedule, and for troubleshooting that isn’t printer-specific, the first-layer troubleshooting guide is a useful general reference. QIDI’s larger MAX4 uses the newer QDC diagnostic framework rather than these QDE codes.