A help desk ticket comes in at 9:05 a.m.: "Printer is leaving lines down every page, the last job looks garbled, and now it keeps jamming." A second user reports faded prints, while someone else can't get paper to feed at all. Meanwhile, the print queue shows multiple prints pending, and nothing moves.
CompTIA A+ 220-1201 Objective 5.6 expects you to troubleshoot these issues fast and in the right order, because many symptoms share the same root cause. This section walks through a repeatable process that starts with simple checks (paper type, trays, cables, status lights, and queue) before you move to deeper fixes (drivers, spooling, rollers, and consumables). The goal isn't guesswork, it's narrowing the problem with evidence.
By the end, you'll know what to check first for lines down the printed pages, garbled print, paper jams, faded prints, paper not feeding, multipage misfeed, and multiple prints pending in queue. You'll also see how to separate printer hardware faults from OS and network problems, which is a common exam trap.
Start with a quick triage, so you don't chase the wrong problem
Printer issues often look random, but they usually follow patterns. A few minutes of triage can stop you from reinstalling drivers when the real cause is damp paper, a half-seated toner cartridge, or a stuck job in the queue. The goal is simple: confirm the symptom, isolate where it occurs, then test the fastest path to proof.
Treat triage like a medical intake. You want facts you can repeat, not guesses. Once you lock down what "garbled" or "faded" means on this device, the next steps become obvious.
Ask the right questions and verify the symptom
Start by getting a clean description, then match it to what you see. Users often mix symptoms, like "lines" (a print quality defect) with "jams" (a paper path fault). Pin down the conditions first, because troubleshooting changes based on paper source, job type, and whether the problem shows up on internal copies.
Use this quick checklist to capture the key facts:
- What document: PDF, browser page, Word doc, label template, photo, or spreadsheet.
- Which tray: Tray 1, Tray 2, manual feed, bypass tray, or multipurpose tray.
- Which paper: size (Letter, A4, Legal), type (plain, glossy, labels), and weight.
- When it started: after a toner change, paper refill, power outage, firmware update, or new PC.
- Where it happens: only from one PC, from all PCs, over network only, or USB too.
- Copies vs. prints: does it happen on copies from the scanner glass/ADF, or only on computer prints?
That last item is a high-value separator. If copies look bad, you are likely dealing with printer hardware, consumables, or the paper path. If copies look fine but computer prints look wrong, focus on drivers, settings, the spooler, or the application.
Next, print a printer status page or configuration page from the printer's own menu. This helps because it bypasses the computer, the driver, and the app. In other words, it tests the printer on its own terms. If the status page has lines, fading, or smears, you have strong evidence of a device-side problem.
If you can reproduce the issue on a printer-generated page, don't waste time on driver changes yet.
Run two fast isolation tests: printer self-test and a different device
After you confirm the symptom, run two quick tests that narrow the fault domain. These tests save time because they reduce the "search area" from the whole print system to either the printer or the sending device.
Test 1: Print the printer's internal test page (self-test). Use the control panel to print a test page, quality report, or configuration page.
- If the self-test looks bad, suspect hardware, consumables, or paper path. For example, repeated lines can point to a dirty roller or imaging component. Faded output can point to low toner, clogged nozzles, or a bad cartridge. Jams and misfeeds point to pickup rollers, worn separation pads, or incorrect paper loading.
- If the self-test looks fine, the printer likely works. Then shift attention to the PC side: driver choice, print preferences, corrupted jobs, spooler issues, or queue problems.
Test 2: Print from a different device. Send the same document from another workstation, a test laptop, or even a phone (if supported). Keep the paper and tray the same to avoid changing variables.
- If the second device prints correctly, the issue follows the first PC. That supports a driver, settings, or spooler/queue cause.
- If both devices produce the same problem, the issue likely sits with the printer, its network path, or the specific tray and media.
When possible, also change the connection type as a tie-breaker. Try USB instead of network (or network instead of USB). A successful USB print can point to a network print queue, port, or print server problem, while failures on both paths suggest a printer-side defect.
Check paper and consumables before changing settings
Before you change advanced settings, confirm the basics that cause the most tickets. Paper and consumables problems often mimic driver issues, yet they have simpler fixes. A printer cannot "fix" damp paper or a misloaded tray with a setting.
Start with paper handling checks:
- Confirm the paper size matches the tray and the job (Letter vs. A4 mistakes cause jams and misfeeds).
- Use dry, flat paper. Moisture can cause curling, sticking, and multipage feeds.
- Adjust tray guides so they touch the stack lightly. Loose guides invite skew and jams.
- Remove overfilled stacks. Overfilled trays increase pickup failures and multipage misfeeds.
- Fan the stack if sheets cling together, then reload it squarely.
Then verify consumables and seating:
- Check toner or ink levels, but don't rely on the percentage alone. A near-empty cartridge often causes fading or light bands.
- Reseat the cartridge and confirm all packaging, seals, and pull tabs are removed.
- Use manufacturer-recommended media for labels, glossy paper, and heavy stock. Unsupported media can shed dust, slip, or melt on hot fusers.
Paper storage matters more than most people think. Keep paper sealed in its wrapper until use, and store it away from humidity. If the issue started right after opening an old ream, swap in a fresh sealed pack before you adjust drivers or print quality settings.
Lines down the page and faded prints, trace the cause and fix it
Print defects feel random until you treat them like clues. A line, streak, or light band usually comes from one part of the print path failing the same way on every page. Start by confirming whether the defect appears on a printer-generated report page. Then compare it to a copy made from the scanner. This simple split, print engine vs. scan path, saves time and prevents unnecessary driver work.
When you document what you see (vertical vs. horizontal, single color vs. all colors, repeats at regular spacing), you can often name the part before you open the printer.
Lines or streaks, what they usually mean on inkjets and lasers
On inkjets, lines and missing bands often point to ink delivery problems. Dried ink or air in the line can block nozzles, so the printer lays down color unevenly. You may see thin white lines through text or graphics, or a single color dropping out (for example, photos look green because magenta no longer prints). A misaligned printhead can also create "shadow" edges that look like faint streaks.
On laser printers, strong vertical streaks often trace back to the imaging system. A scratched drum can mark every page like a damaged paint roller. Dirty or worn rollers can also leave streaks, especially if toner dust builds up where paper contacts rubber. If the defect looks like gray shading or a repeating smudge, suspect toner contamination in the cartridge area or a failing drum unit.
Lines can also come from the scanner, not the print engine. If copies (not prints) show a single dark line, check the ADF scan strip first. A tiny speck of correction fluid or toner on that narrow glass can draw a sharp line through every scanned page, like a hair stuck in a camera lens.
A quick rule helps you narrow the root cause:
- Vertical lines often point to the drum, printhead, or scanner glass/ADF strip, because the same spot stays "in the path" as the page moves.
- Repeating marks often match the circumference of a drum or roller, because the same damaged area rotates and stamps the page at regular intervals.
If the line appears on the printer's internal test page, focus on hardware and consumables. If it appears only on scanned copies, clean the glass before replacing parts.
Step-by-step fixes that don't make it worse
Fix print quality issues in a controlled order. The goal is to clean or reseat first, then replace only what testing supports. That approach reduces wasted supplies and avoids damage to sensitive parts.
Start with the least invasive steps:
- Print a nozzle check or quality report (inkjet). If gaps appear, run a built-in cleaning cycle, then re-test. Limit back-to-back cleanings, because they use a lot of ink and can overheat some printheads.
- Reseat the ink or toner cartridge. Remove it, check for seals or tape, then reinstall it firmly. A half-seated cartridge can cause streaks, fading, or odd density shifts.
- Swap in a known-good cartridge if you have one. This is one of the fastest ways to prove a consumable fault.
- Clean accessible rollers with a lint-free cloth and an approved cleaner (often water or isopropyl alcohol, depending on vendor guidance). Rotate rollers by hand as you wipe, and let them dry before printing.
- Clean the scanner glass and ADF strip if the issue shows up on copies. Use a soft, lint-free cloth and glass cleaner applied to the cloth, not sprayed onto the device.
For some laser models, you can also clean the corona wire (if present). Follow the printer's instructions, because the corona assembly is fragile and sits near high-voltage components. Many cartridges include a small built-in cleaner tab for this purpose.
A few "don'ts" prevent costly mistakes:
- Don't touch the drum surface with your fingers. Skin oils can cause permanent print defects.
- Don't use abrasive pads or paper towels on glass, drums, or rollers.