Canon NP-4050 Copier Service Manual, 1991–1993 (P/N FY8-13BF-010)

This is Canon’s factory service manual for the 220/240V NP-4050 desktop copier (P/N FY8-13BF-010, Revision 1, January 1993).

PDF Bookmarks and Circuit Detail

Navigation and schematic detail: The PDF has embedded section bookmarks. PDF text search is unavailable. Small connector numbers, pin labels, and wire codes are easier to read when zoomed in, although some wire labels in the general circuit diagram remain faint.

The download is one printable English-language PDF with 326 pages, including the original cover page and all 39 pages of the appendix.

Copying, Paper Feed, and Copier Repair

These are selected highlights from the manual. Canon also covers user ID mode and the copier’s paper and toner messages.

• Copying process: Pre-exposure, primary charging, image exposure, development, pre-transfer, transfer and separation, fixing, drum cleaning, and blank-exposure control.

• Optics and corona assemblies: Scanner and lens drive service, mirror cable routing and tension, optical-length adjustment, and drum, exposure lamp, and corona wire service.

• Paper feed and delivery: Pickup, registration, feeder and delivery repairs, plus timing and jam charts for cassette, manual-feed, duplex, overlay, and paper-deck operation.

• Development and fixing: Black developing cylinder and blade service, fixing heater and roller replacement, and fixing nip measurement and adjustment.

• Service Mode: Automatic exposure (AE) and development bias adjustments, live sensor I/O, photointerrupter checks, and self-diagnostic codes.

• Wiring and maintenance: DC controller and power supply circuit diagrams, special tool numbers, and scheduled servicing charts.

This manual is suited to copier service technicians who read circuit diagrams and use a meter and Canon’s special service tools.

Paper Feed, Timing, and Options

The Cassette Feeding Unit-D1 adds the third and fourth cassettes. Canon covers its pickup and separation assemblies and the Paper Deck Pedestal-D1’s left and right pickup units, feeder and separation rollers, and lifter cable routing. The manual also traces both units’ controller and sensor signals.

Timing charts show scanner travel, horizontal registration, duplex switch-back and set-back, and fixing and delivery. Jam charts distinguish delay, timing, and stationary faults at pre-registration, the lower feeder, manual feed, delivery, and the paper deck. Paired with live I/O checks, the charts help narrow intermittent jams to a sensor, clutch, solenoid, or paper-path timing fault.

The RDF-B1, Sorter-A1, Sorter-B1, Stapler Sorter-A1, and Auto Stapler Folder-A1 appear in the Service Mode tables. Canon provides accessory fault codes and an RDF document stop adjustment. The Auto Stapler-A1 appears in the option list. Mechanical repair chapters cover the copier, cassette feeding unit, and paper deck.

Drum, Developer, and Fixing Assembly

The mechanical chapters cover corona wire routing and height settings, developing blade gap adjustment, and thermistor and thermoswitch contact checks. Fixing assembly service includes preparing the lower roller cleaner with silicone oil and resetting the Service Mode counter after cleaning belt replacement.

Canon calls out three handling risks: damaging the developing cylinder with the FY9-3006 gap gauges, exposing the photosensitive drum to room light, and letting the separation claw contact the feeder belt.

Disconnect the copier from AC power before opening the exposure, fixing, power-supply, or high-voltage sections.

Controller Diagnostics and Calibration

The DC controller diagrams identify main CPU Q223, sub-CPU Q221, the gate array, ROM and RAM, and the D/A converter. The I/O sheets trace Q2 delivery, Q4 manual feed, registration, cassette, document-size, toner, and fixing-temperature signals. The appendix includes the General Timing Chart and dedicated circuit diagrams for the AE and document-size sensors, HVT and HVT AC, and both feeder controllers.

Service Mode covers Display, I/O Display, Adjust, Function/Inspection, User Option, and Counter. It includes lamp and LED checks, toner supply, error clearing, RAM initialization after DC controller replacement, and adjustments for leading-edge blanking, scanner stop position, registration, and transfer and separation current. Self-diagnosis tables cover fixing temperature, motor and scanner feedback, lens home position, CPU/IPC communication, and toner faults.

Installation and Scheduled Service

Installation covers site selection, unpacking, drum setup, toner initialization, cassette-size conversion, final image checks, relocation, and Control Card V installation. The specifications list copy ratios and speeds, media and cassette arrangements, operating conditions, power, dimensions, weight, and accessory capacities.

Canon provides scheduled replacement and durable-parts tables, a servicing chart, and cleaning and lubrication references. Tool listings include the TKN-0093 door-switch actuator, CK-0054 spring scale, CK-0426 plier extensions, TKN-0464 cleaning oil, and CK-0439 corona wire damping material. Canon references a separate Parts Catalog for parts identification.

Sample Mirror Cable and Fixing Nip Settings

The mirror drive cable check specifies a spring-gauge reading of 300–400 g for a 10 mm forward deflection at the span shown in Figure 4-203, with the No. 1 mirror mount toward its home position.

With both fixing rollers fully warmed up, Canon specifies a center nip width of 5.3 ± 0.3 mm on a solid-black A3 test copy. The two outer measurements, taken 10 mm in from the paper edges, may differ by up to 0.5 mm.