The AD5X’s screen reports problems as numbered E-codes, and Flashforge keeps a full list of them on its wiki. Most have a simple check that resolves them before they point to a failed part, so it’s worth working through the reversible causes first instead of assuming the worst from the code number alone.
Several general codes trace back to everyday causes. E0002, communication with the MCU interrupted, is usually a loose extruder cable rather than a damaged board. E0012 through E0014 cover X, Y, and Z homing errors, and the first thing to check is whether wiring or debris is blocking the axis, not a failed sensor. E0017, command exceeds queue limit, just means the print speed or model resolution is too demanding for the buffer, and lowering overall speed or resolution in the slicer clears it. E0019 is a USB read error, usually fixed by reformatting the drive to FAT32, and E0088 shows up when the printer doesn’t recognize the plate as an official PEI sheet.
The IFS has its own set of codes, in the E0100 to E0114 range, separate from the printer’s general faults. E0100 through E0103 are per-channel feeding timeouts, most often filament tangled at the spool or stuck at the 4-in-1 connector rather than a broken part. E0104 through E0107 are the matching retracting timeouts, often caused by the cutter failing to fully sever the filament. E0109 covers an odometer roller that isn’t moving, which is worth checking against a clogged nozzle before assuming a sensor has failed. E0110 is a mismatch between the filament type set on the material station and the one set in the slicer, and E0113 usually means filament wasn’t retracted cleanly and is still sitting against the extruder’s sensor. E0114 is an IFS homing error, tied to the clutch motor or the homing sensor itself.
For anything outside these patterns, the printer’s on-screen error list and Flashforge’s wiki cover the full set with matching fixes.
Most of these codes trace back to routine upkeep rather than a failed part, such as a loose extruder cable, filament tangled at the spool or the 4-in-1 connector, or a plate the firmware doesn’t recognize. The AD5X maintenance schedule covers exactly those checks, and running through it before assuming a fault often clears a homing or IFS error without ever opening a support ticket.