Exact model-family answer directory

Canon MAXIFY GX4020 troubleshooting

Choose the symptom actually shown by 5779C002. Canon printer; PIXMA/MegaTank/MAXIFY/imageCLASS ink/toner systems and maintenance paths differ. Error codes remain separate records because the same characters can mean different things on another platform.

offlinepaper jamnot printingblank pagesfadedsmudges

Reviewed records

16 exact answers

Not sure where the fault is?

Canon · ADF jam

Canon MAXIFY GX4020 automatic document feeder jams, skews or pulls multiple pages

For the Canon MAXIFY GX4020, original condition, guides, roller/separation pad and sensor path should be checked.

Open record Canon · cartridge not recognized

Canon MAXIFY GX4020 does not recognize ink or toner

For the Canon MAXIFY GX4020, exact part compatibility, shipping seals, contacts, seating and firmware should be checked before replacement.

Open record Canon · firmware

Canon MAXIFY GX4020 firmware update will not install

For the Canon MAXIFY GX4020, exact model, stable power/network and signed update path are required.

Open record Canon · offline

Canon MAXIFY GX4020 is offline or unavailable

For the Canon MAXIFY GX4020, prove the printer can print internally before repairing the network or computer queue.

Open record Canon · smudges

Canon MAXIFY GX4020 leaves smudges, spots or repeated marks

For the Canon MAXIFY GX4020, mark spacing and whether ink/toner is fused/dry identify media, roller, drum, fuser or maintenance faults.

Open record Canon · blank pages

Canon MAXIFY GX4020 prints blank pages

For the Canon MAXIFY GX4020, supply installation/venting, protective seals, nozzle/printhead output and driver document content should be separated.

Open record Canon · faded

Canon MAXIFY GX4020 prints faded, streaked, banded or with missing colors

For the Canon MAXIFY GX4020, internal quality output separates hardware/supply from app, driver and color profile.

Open record Canon · wrong colors

Canon MAXIFY GX4020 prints the wrong colors

For the Canon MAXIFY GX4020, internal output, one color-management owner, paper/ink profile and supply state should be controlled.

Open record Canon · slow printing

Canon MAXIFY GX4020 prints very slowly

For the Canon MAXIFY GX4020, resolution/quality mode, duplex, document complexity, connection and spool/driver should be timed separately.

Open record Canon · not printing

Canon MAXIFY GX4020 receives jobs but does not print

For the Canon MAXIFY GX4020, printer error state, local engine, connection, queue, driver and document should be separated.

Open record Canon · scanner not found

Canon MAXIFY GX4020 scanner is not found or scanning fails

For the Canon MAXIFY GX4020, local scanner operation, connection, driver/app, permissions and destination storage should be separated.

Open record Canon · maintenance

Canon MAXIFY GX4020 shows a maintenance box, drum, fuser, waste toner or service message

For the Canon MAXIFY GX4020, the exact consumable/service item and whether it is customer-replaceable are model-specific.

Open record Canon · paper jam

Canon MAXIFY GX4020 shows a paper jam or repeatedly jams

For the Canon MAXIFY GX4020, the exact feed/duplex/output location, media condition and a complete sheet count matter.

Open record Canon · AirPrint

Canon MAXIFY GX4020 will not AirPrint, Mopria or print from a phone

For the Canon MAXIFY GX4020, printer LAN connection, same-network discovery, guest isolation, protocol support and app permissions should be separated.

Open record Canon · Wi-Fi

Canon MAXIFY GX4020 will not connect to Wi-Fi

For the Canon MAXIFY GX4020, printer radio, supported band/security, setup mode, router isolation and account/app should be separated.

Open record Canon · duplex

Canon MAXIFY GX4020 will not print or scan two-sided

For the Canon MAXIFY GX4020, model capability, driver option, paper size/type and accessory detection must align.

Open record

Confirm the model first

Which units this covers, and how to tell yours is one of them

Every answer below is scoped to these model identifiers. A neighbouring model in the same line can use a different part, a different reset sequence or a different radio, so matching the identifier before following a procedure is the step that decides whether the rest of the page applies to you.

Model numbers and patterns: 5779C002
What that covers: Canon printer; PIXMA/MegaTank/MAXIFY/imageCLASS ink/toner systems and maintenance paths differ.

Published specification

What is true of this model and changes how you fix it

These are the properties that decide which procedure applies. Each is read from the manufacturer’s own published figures for this model, not carried over from a sibling that shares its retail name.

Type — BUSINESS refillable INK TANK all-in-one (MAXIFY): A business MAXIFY MegaTank AIO — refillable ink BOTTLES with pigment inks and office features, below the GX7021 in speed/capacity. Still inkjet, so the printhead can CLOG if unused.
Pigment ink + volume: Pigment inks for durable documents; very low running cost. Don't run tanks dry; initial charging uses some starter ink (normal).
Connectivity: Wi-Fi/Ethernet/USB via the Canon app; 'offline' is usually a network/queue issue.

Where these figures were read. canon.com MAXIFY GX4020 (business refillable INK TANK AIO), read 2026-09-01

Manufacturer support for this product line. Canon Support — Printer support. Official Canon model manuals, drivers, errors and maintenance support.

Exact questions

Questions that only have an answer for the Canon MAXIFY GX4020

Each answer below uses this model’s own published figures. The same question asked about a different model in the line has a different answer, which is why it is answered here rather than on a general page.

My Canon MAXIFY GX4020 prints faded with full ink tanks.+

That is a printhead clog — the MAXIFY is a refillable inkjet, so full tanks do not prevent clogs, especially if it has been idle. Run the nozzle check then Cleaning and, if needed, Deep Cleaning from the menu/software, printing a pattern after each to gauge improvement. Make sure no tank was run dry (air in the lines clogs it). Print regularly to keep the head clear. The pigment ink and tank refills keep running costs very low for office use.

Structured depth, not empty permutations

Every published record carries a direct answer, scope, ordered fixes, risk notes and sources.

Device and manufacturer hubs share a consistent record system, but each answer carries the relevant controls, fault boundaries, consequences and official support entry point for that platform.

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