Chapter 4: Printers and Multifunction Devices

A+ Core 1 — 220-1101 | Objectives 3.6 & 3.7

Chapter 4:
Printers & Multifunction Devices

Printer types, laser imaging process, components, interfaces, and maintenance. One of the most heavily tested hardware topics on the 220-1101 exam.

21 Slides Objectives 3.6 & 3.7 Laser • Inkjet • Thermal • Impact • 3D Exam 220-1101

Slide 2 of 21

Printer Types Overview

Five printer categories tested on the A+ exam — each uses a distinct technology.

Laser

Inkjet

Thermal

Impact

Printer Type	Technology	Primary Use
Laser	Electrophotographic process using toner powder	High-volume office printing
Inkjet	Liquid ink sprayed through microscopic nozzles	Home use, photo printing
Thermal	Heat applied to special heat-sensitive paper	Receipts, labels, POS systems
Impact	Physical pin strike through an ink ribbon	Multi-part forms, carbon copies
3D (FDM)	Additive manufacturing with heated filament	Prototyping, custom parts

Exam Tip

Know the key differentiator for each type. Impact printers are the ONLY type that can create multi-part carbon copies because the physical strike transfers through layers. No other print technology can replicate this.

Slide 3 of 21

Impact Printers

Dot-matrix and daisy wheel — the only printer type that physically strikes the paper.

Daisy Wheel

A wheel with characters molded onto "petals" rotates to position the correct character, then strikes through a ribbon. Produces letter-quality text only — cannot print graphics. Very slow by modern standards. Largely obsolete.

Dot-Matrix

Printhead contains a column of pins (9-pin or 24-pin). Solenoids fire pins against an ink ribbon to form characters from a dot pattern. Can produce both text and simple graphics. The most common impact printer still in active use today.

Component	Function
Printhead	Contains 9 or 24 pins that strike the ribbon to form characters
Ribbon	Ink-soaked fabric cartridge that transfers ink to paper on impact
Platen	Rubber roller that holds paper flat and advances it line by line
Solenoid	Electromagnetic actuator that fires individual pins on command
Tractor Feed	Sprocket-driven mechanism that pulls continuous-feed perforated paper

Maintenance

Replace the ribbon when print becomes faint. Replace the printhead if pins fail (missing dot rows in output). Use continuous-feed tractor paper, not cut sheet, for high-volume impact printing.

Slide 4 of 21

Inkjet Components

Liquid ink forced through nozzles — popular for home use and photo output.

Component	Function
Print Head / Ink Cartridge	Contains nozzles; may be integrated with cartridge or a separate permanent head
Head Carriage	Holds the print head and traverses horizontally across the page
Carriage Belt	Connects carriage to the stepper motor for precise horizontal movement
Stepper Motor	Provides exact positional control for both carriage and paper feed
Pickup Roller	Grabs a sheet from the paper tray and feeds it into the paper path
Separation Pad	Ensures only one sheet is fed at a time; prevents multi-feed jams
Duplexing Assembly	Reverses paper for automatic two-sided printing

Exam Tip

Multiple pages feeding at once = worn separation pad. No paper feeding at all = check the pickup roller. These are the two most-tested inkjet feed issues.

Warning

Inkjet nozzles clog if the printer sits unused. Run the built-in head cleaning utility periodically, or print at least one page per week, to prevent dried ink from blocking nozzles.

Slide 5 of 21

Inkjet Maintenance

Routine tasks to keep inkjet output sharp and paper feeding reliably.

Clean Heads

Use the printer's built-in head cleaning utility to purge dried ink from nozzles. Access through the printer's control panel or driver software. Run when output shows streaks, missing lines, or faded sections. Each cleaning cycle consumes some ink.

Replace Cartridges

Replace when the printer reports low ink or output becomes pale and uneven. Using third-party refilled cartridges may void warranty and can cause nozzle issues. Store spare cartridges in a cool, sealed environment to prevent early drying.

Calibrate

Run the head alignment utility after replacing cartridges to ensure print heads are synchronized. Misaligned heads cause double-image artifacts and blurry text. Calibration prints a test pattern and adjusts offsets automatically or prompts user selection.

A user complains that their inkjet produces streaky output with one color completely missing. The printer was unused for three months. Solution: run the head cleaning utility twice, then print a nozzle check pattern. If the nozzle remains blocked, a second cleaning cycle followed by calibration typically resolves it.

Slide 6 of 21

Laser Printer Components

Electrophotographic process — know every component and its role.

Component	Function
Toner Cartridge	Houses toner powder, imaging drum, charge corona/roller, developer roller, and cleaner blade
Imaging Drum	Light-sensitive photosensitive cylinder where the electrostatic image is formed
Laser Scanner Assembly	Contains laser diode, rotating mirror, and fixed mirrors to write image on drum
HVPS	High-Voltage Power Supply — powers corona wires/rollers with high voltage
Transfer Corona/Roller	Applies +600 VDC charge to paper to attract negatively charged toner from drum
Fusing Assembly	Heat roller + pressure roller that permanently melts toner into paper at ~350°F
Ozone Filter	Filters ozone gas produced by high-voltage corona wires; replace per maintenance schedule
Duplexing Assembly	Flips paper to enable automatic two-sided printing

Safety

Fuser operates at ~350°F (177°C). Allow it to cool fully before servicing. The HVPS carries lethal voltages. Always power off and unplug before opening the printer.

Exam Tip

Never expose the imaging drum to light — even brief exposure damages the photosensitive coating permanently. Keep the toner cartridge in its packaging until installation.

Slide 7 of 21

The Laser Imaging Process

Seven sequential steps — one of the most heavily tested topics on the 220-1101.

Mnemonic — All 7 Steps

P — C — E — D — T — F — C

Processing → Charging → Exposing → Developing → Transferring → Fusing → Cleaning

"People Can't Easily Develop True Friendship Connections"

1

Processing — RIP converts page to bitmap in printer memory.

2

Charging — Corona wire / charge roller applies uniform −600 VDC to drum.

3

Exposing — Laser writes image; exposed areas drop to −100 VDC.

4

Developing — Developer roller (−600 VDC) deposits toner onto −100 VDC areas.

5

Transferring — Transfer corona applies +600 VDC to paper; toner migrates from drum.

6

Fusing — Heat (~350°F) and pressure melt toner permanently into paper.

7

Cleaning — Rubber blade scrapes residual toner; erase lamp resets drum charge.

Slide 8 of 21

Laser Process: Voltages & Temperatures

The exam tests specific values — these are not approximate, they are exam-exact figures.

Step	Component	Value	Significance
Charging	Primary corona / charge roller	−600 VDC	Uniform negative charge applied to entire drum
Exposing	Laser-discharged areas	−100 VDC	Image areas become less negative, attracting toner
Developing	Developer roller	−600 VDC	Matches drum charge; toner moves to lower-charge areas
Transferring	Transfer corona / roller	+600 VDC	Positive charge on paper attracts negatively charged toner
Fusing	Heat roller (fuser)	~350°F	Melts toner permanently into paper fibers

Electrostatic Principle

Toner carries a negative charge. It migrates from the developer roller (−600V) to the less-negative drum areas (−100V) because the potential difference is smaller there — a fundamental property of electrostatic attraction.

Exam Tip

The exam often asks why toner moves to exposed areas. Answer: those areas are LESS negative (−100V) than the developer roller (−600V), so the toner is attracted toward the lower charge differential.

Slide 9 of 21

Thermal Printers

Heat creates the image — no ink, no ribbon, no toner. Common in retail and healthcare.

How It Works

A heating element array applies precise heat to thermal paper. The paper is coated with a chemical that turns dark when heated. No consumables other than the paper roll itself. Silent, few moving parts, long service life.

Thermal Paper

Special paper with a heat-sensitive waxy coating. Turns black at the heated points. Expensive compared to plain paper. Fades over time, especially in heat or sunlight. Do not store receipts in warm environments — they will become unreadable.

Typical Use Cases

POS receipt printers, label makers, airline ticket kiosks, ATM receipts, medical wristbands, shipping label printers. Anywhere quiet, fast, low-maintenance printing of temporary documents is needed.

Component	Function
Heating Element	Array of tiny resistive elements that apply heat to the paper surface
Feed Assembly / Platen	Rubber roller that advances thermal paper past the heating element
Thermal Paper Roll	Heat-sensitive media; the only consumable for direct thermal printers

Maintenance

Replace thermal paper roll when empty. Clean the heating element with isopropyl alcohol on a lint-free swab to remove adhesive and paper dust buildup. Clear debris from the paper path to prevent jams and uneven heating.

Slide 10 of 21

3D Printers (FDM)

Fused Deposition Modeling — additive manufacturing layer by layer.

PLA (Polylactic Acid)

Biodegradable, plant-based material. Easy to print, low temperature required, most common filament. Minimal warping, no heated bed required. Best choice for general prototyping. Not suitable for high-heat environments.

ABS (Acrylonitrile Butadiene Styrene)

Stronger and more heat-resistant than PLA. Shrinks as it cools — requires a heated bed to prevent warping. Produces fumes (styrene) during printing — requires good ventilation. Used for functional parts that must withstand heat or mechanical stress.

Component	Function
Print Bed / Plate	Heated surface where the object is built layer by layer from the bottom up
Extruder	Heats filament to melting point and forces it through a nozzle onto the build surface
Filament	Plastic material (PLA, ABS, PETG, etc.) fed from a spool into the extruder
Cooling Fan	Rapidly cools deposited material to maintain shape; prevents stringing
PCB Controller	Controls extruder and bed movement on X, Y, and Z axes

Exam Tip

3D printer files use the .STL extension (STereoLithography). Files are sliced into layer instructions by slicer software before sending to the printer. ABS shrinks and requires ventilation — both are exam-tested facts.

Slide 11 of 21

3D Printing Process & Resin (SLA)

FDM workflow from design to object, plus the resin printing alternative.

1

Design — Create the 3D object using CAD software (Fusion 360, TinkerCAD, Blender).

2

Export — Save as a .STL file. The STL format describes the surface geometry as triangular mesh faces.

3

Slice — Import the .STL into slicer software (Cura, PrusaSlicer). The slicer generates layer-by-layer G-code instructions for the printer.

4

Transfer — Send the sliced file to the printer via USB drive, SD card, or network/Wi-Fi connection.

5

Calibrate — Printer calibrates the bed level and home position on X, Y, and Z axes before beginning.

6

Print — Object is built layer by layer from the bottom up. Each layer bonds to the previous through heat fusion.

Resin / SLA Printers

Stereolithography (SLA) uses liquid photopolymer resin cured by UV light. Much higher resolution than FDM — produces very fine details. Messier process: uncured resin is toxic and requires post-processing wash in isopropyl alcohol, then UV curing.

Key File: .STL

The exam specifically calls out .STL as the standard 3D printer file format. Do not confuse with .CAD (modeling), .OBJ, or .GCODE (post-slicing machine instructions).

Slide 12 of 21

Printer Connection Types

Local, network, and legacy interfaces — USB is the current standard for local connections.

Interface	Type	Description
USB	Local	Most common local connection; plug-and-play; faster than legacy options
Ethernet (RJ-45)	Wired Network	Network printing via TCP/IP; printer has its own IP address; supports multiple users
Wi-Fi	Wireless Network	Convenient wireless network printing; may require additional security configuration
Bluetooth	Wireless Local	Short-range wireless; common on mobile-friendly printers for direct device printing
Parallel (Legacy)	Legacy Local	8 bits over 8 wires; DB-25 (PC) to Centronics-36 (printer); IEEE 1284; obsolete
Serial (Legacy)	Legacy Local	1 bit at a time; DB-9 connector; RS-232; very slow; found only on legacy equipment

Exam Tip

Parallel used a DB-25 connector on the PC side and a Centronics 36-pin connector on the printer side. Serial used DB-9 (9-pin). Both are obsolete but remain on the exam. USB replaced both in the late 1990s.

Slide 13 of 21

Page Description Languages

PDLs define how the printer renders a complete page — PostScript vs. PCL vs. GDI.

PostScript (Adobe)

Industry standard for graphics and publishing. The printer itself contains the interpreter and does all the rendering. Resolution-independent. Produces consistent output across different PostScript devices. Higher cost printers. Best for complex graphics, typography, and print shops.

PCL (HP)

Printer Command Language, developed by HP. Widely supported across most laser and inkjet printers. The computer does some processing; the printer handles the rest. Faster for text-heavy documents than PostScript. Efficient and broadly compatible — the most common PDL in offices.

GDI (Microsoft)

Graphics Device Interface — the host computer (Windows) does ALL the rendering before sending the bitmap to the printer. Printers using GDI have no onboard processor for page rendering. Lower hardware cost but higher CPU load on the host. Sometimes called "host-based printing."

PostScript vs. PCL

PostScript: printer has its own processor, better for complex graphics, higher cost. PCL: efficient for text, widely compatible, lower cost. Common exam question — know which one processes the image ON the printer vs. on the host.

Virtual Printers

Print to PDF, Print to XPS (Microsoft XML Paper Specification), Print to File. Virtual printers capture output as a digital file rather than sending it to physical hardware. Useful for document archiving and testing drivers.

Slide 14 of 21

Network Printing Technologies

Protocols and services that enable printers to be shared across a network.

TCP/IP Printing

Standard protocol for network printing. Printer is assigned a static or DHCP IP address. Print jobs sent over port 9100 (raw) or port 631 (IPP). Supported by all modern network-capable printers. Requires knowing the printer's IP to add it manually.

Bonjour (Apple)

Apple's zero-configuration networking protocol. Automatically discovers printers on the local network without manual IP entry. Uses mDNS (multicast DNS) over the local subnet. Built into macOS and iOS. Simplifies printer discovery in mixed Apple environments.

AirPrint

Apple technology for wireless printing directly from iOS and macOS devices without installing drivers. The printer must advertise AirPrint support. The operating system handles all communication. Common on modern Wi-Fi printers marketed for home and SMB use.

Cloud Printing

Send print jobs to a remote printer anywhere in the world via internet-connected services. The printer registers with a cloud service (e.g., HP ePrint, previously Google Cloud Print). Jobs are routed through the cloud, allowing mobile printing from any location.

Exam Note

Bonjour is Apple's zero-config discovery — it is often the answer when the question involves automatic printer discovery on an Apple network. AirPrint is Apple's driverless wireless printing standard for iOS/macOS.

Slide 15 of 21

Installing & Configuring a Printer

Six-step local installation process and key configuration settings.

1

Attach — Connect via USB (local) or configure the network IP. Connect AC power.

2

Install Driver — Install the manufacturer driver from the disc or vendor website. Update to latest version. Match driver to OS version and architecture (32-bit vs. 64-bit).

3

Configure Settings — Set default paper size, print quality, duplex preference, and tray assignments through the driver preferences.

4

Print Test Page — Verify connectivity, correct driver, and print quality with a test page from the driver or printer control panel.

5

Calibrate — Run alignment and calibration utilities (especially inkjet) to ensure accurate color and head positioning.

6

Educate Users — Brief users on basic operation, paper loading, consumable replacement, and how to access the print queue.

Setting	Description
Duplex	Automatic two-sided printing; requires duplexing assembly hardware
Orientation	Portrait (vertical) or Landscape (horizontal) page layout
Tray Settings	Assign paper size and type per tray; configure tray priority order
Quality	Draft / Normal / High — trades speed and consumable use against output quality

Slide 16 of 21

Printer Security

Protecting sensitive documents and controlling printer access in corporate environments.

User Authentication

Require users to log in at the printer or through the print dialog before jobs are released. Controlled via directory integration (Active Directory). Prevents unauthorized use and tracks per-user print volume for cost allocation.

Badging / Card Reader

User swipes an ID/proximity card at the printer to release their queued jobs. The print job is held in a secure queue on the print server until the badge is authenticated. Common in healthcare and legal environments with strict document control requirements.

Secured Prints (PIN)

User sends a job with a PIN code. The job is held in the printer's memory until the user walks up and enters the PIN on the printer's control panel. Prevents sensitive documents from sitting unattended in the output tray — direct exam topic.

Audit Logs

Enterprise printers maintain logs tracking who printed, what document (name), page count, date/time, and which printer. Critical for compliance with regulations protecting PII (Personally Identifiable Information) and PHI (Protected Health Information).

Exam Tip

"Secured prints" and "PIN-released printing" are the same concept. The exam describes a user needing to enter a PIN at the printer before the job prints. The answer is always: secured printing / secure print release.

Slide 17 of 21

Laser Printer Maintenance

Consumables, scheduled kits, paper specs, and environmental factors.

Consumables

Toner cartridge is the primary consumable. Replace when output becomes faded, streaky, or the printer reports low toner. Some cartridges include the drum and other components — check whether the drum is replaceable separately. Never shake a nearly-empty cartridge — it can damage the drum coating.

Maintenance Kits

Manufacturer-specified kits containing replacement rollers (pickup, feed, transfer), the fuser assembly, and the separation pad. Triggered by a page-count threshold (e.g., every 200,000 pages). The printer may display a maintenance kit warning. Ignoring it causes paper feed problems and fuser failures.

Paper Specifications

Paper weight measured in lb per 500-sheet ream (20 lb bond = standard office paper). Caliper = paper thickness. Cotton-content paper (resume paper) handles differently. Using too-heavy or glossy paper not rated for laser printing can jam the fuser or cause poor toner adhesion.

Environmental Limits

Heat: keep vents clear; never block airflow around the printer. Humidity above 80% causes paper to absorb moisture, leading to curling, misfeeds, and jams. Light exposure damages the photosensitive drum permanently — keep the toner bay closed.

Printer Upgrades

Memory (increases buffer for complex jobs), network card (often proprietary to model), firmware updates (features and compatibility fixes), internal hard drive (stores jobs for secure printing), additional trays/feeders, and finishers (fold, staple, hole punch, sort).

Slide 18 of 21

Troubleshooting Scenarios

Symptom-to-cause mapping — the exam presents symptoms and expects the component diagnosis.

Symptom	Printer Type	Most Likely Cause
Multiple sheets feed at once	Inkjet / Laser	Worn separation pad
No paper feeds at all	Inkjet / Laser	Worn pickup roller
Streaks or lines across page	Laser	Dirty drum or low toner
Toner smears / does not stick	Laser	Fuser assembly failure
Ghost image from previous page	Laser	Cleaning blade worn / drum not cleaned
Faded or missing color bands	Inkjet	Clogged print head nozzles
Date/time resets, BIOS prompts	N/A	CMOS battery — not printer-related
Output too light across entire page	Impact	Worn or dry ribbon
Missing dots in a consistent row	Impact	Failed printhead pin(s)
Faded / blank thermal output	Thermal	Wrong paper orientation (coated side wrong) or dirty heating element

Slide 19 of 21

Exam Practice: Quick Questions

Six A+ style scenario questions — answers in gold. Cover them first.

Q1

A company needs to print three-part carbon invoice forms. Which printer technology is required? — Impact (dot-matrix). It is the only type whose physical strike transfers through carbon paper layers.

Q2

What voltage does the primary corona wire apply to the laser drum during the charging step? — −600 VDC. The entire drum surface is uniformly charged negative.

Q3

A user sends a print job containing sensitive HR data. Which feature ensures the document is not left unattended in the output tray? — Secured printing (PIN release). The job is held until the user enters their PIN at the printer.

Q4

An inkjet printer continuously grabs two sheets at once. Which component is most likely worn? — Separation pad. The pickup roller causes no-feed; the separation pad causes multi-feed.

Q5

A 3D printed object looks correct in slicer software but the printer refuses to read the file. What format should the source file be? — .STL (STereoLithography). The slicer exports G-code; the original model file is .STL.

Q6

A laser printer page shows a faint duplicate of the previous page underneath the current print. Which component failed? — Cleaning assembly (cleaning blade). It failed to remove residual toner from the drum between pages.

Slide 20 of 21

Key Vocabulary

Chapter 4 terms organized by printer category.

Laser

Toner cartridge — powder-based consumable
Imaging drum — photosensitive cylinder
HVPS — High-Voltage Power Supply
Fuser assembly — heat + pressure at ~350°F
Transfer corona — +600 VDC to paper
Ozone filter — absorbs corona ozone gas

Inkjet / Impact

Separation pad — prevents multi-feed
Pickup roller — grabs paper from tray
Head carriage + belt — horizontal traversal
Stepper motor — precise positional control
Platen — rubber roller in dot-matrix
Ribbon — ink transfer medium (impact)

Interfaces & Protocols

PostScript — printer-side rendering (Adobe)
PCL — Printer Command Language (HP)
GDI — host-side rendering (Microsoft)
Bonjour — Apple zero-config discovery
AirPrint — driverless iOS/macOS printing
Parallel / DB-25 — legacy 8-bit interface

Laser 7 Steps

Processing → Charging → Exposing → Developing → Transferring → Fusing → Cleaning

3D / Thermal

.STL — 3D printer source file format
FDM — Fused Deposition Modeling (filament)
SLA — Stereolithography (resin/UV)
PLA — easy biodegradable filament
ABS — strong, shrinks, needs ventilation
Thermal paper — heat-sensitive, no ink needed

Slide 21 of 21 — Chapter 4 Complete

Chapter 4 Summary

Eight key takeaways from Printers and Multifunction Devices.

1

Impact printers (dot-matrix) are the only type that can produce multi-part carbon copies. The physical pin strike transfers ink through layers — no other technology replicates this.

2

The laser 7-step process is: Processing → Charging → Exposing → Developing → Transferring → Fusing → Cleaning. Mnemonic: P-C-E-D-T-F-C.

3

Laser voltages: Drum charged at −600 VDC. Laser writes to −100 VDC. Developer roller at −600 VDC. Transfer corona at +600 VDC. Fuser at ~350°F.

4

Inkjet multi-feed = separation pad. Inkjet no-feed = pickup roller. These are the two most-tested inkjet component questions.

5

Thermal printers require no ink or ribbon — only special heat-sensitive thermal paper. Used for POS receipts and labels. Clean the heating element; do not store thermal paper in warm environments.

6

3D printer files use .STL format. ABS filament shrinks as it cools and requires ventilation. FDM prints layer by layer; SLA (resin) uses UV light for higher resolution.

7

PDLs: PostScript = printer-side rendering (Adobe). PCL = widely compatible (HP). GDI = host-side rendering (Microsoft Windows). PostScript printers have their own onboard processor.

8

Secured prints require a PIN at the printer before the job releases. Bonjour = Apple zero-config discovery. AirPrint = driverless iOS/macOS printing. Never expose the laser drum to light.