HP M234dw copies or scans show smudges, specks or poor quality
Cause 1 of 4Dirt on the scanner glass or the white backing under the lid. Source: Improve copy and scan image quality: Check the scanner glass for dirt and smudges, p. 89
First checkWipe the scanner glass.
Causes and checks
Dirt on the scanner glass or the white backing under the lid. Source: Improve copy and scan image quality: Check the scanner glass for dirt and smudges, p. 89
- Wipe the scanner glass. See Clean the scanner glass.
Paper settings do not match the paper. Source: Improve copy and scan image quality: Check the paper settings, p. 89
- In the EWS, go to the System tab, click Paper Setup, change the settings and click Apply.
The copy optimization does not match the original. Source: Improve copy and scan image quality: Optimize for text or pictures, pp. 89, 90
- In the EWS, open the Copy tab and pick Optimize: Mixed for text and graphics, Text for mostly text, or Picture for mostly graphics.
- Click Apply.
The original is larger than the printable area and its edges are cropped. Source: Improve copy and scan image quality: Edge-to-edge copying, p. 90
- Move a smaller original 4 mm (1/6 in) away from the corner marked on the scanner, then copy or scan again.
- Use Reduce/Enlarge to shrink an original that is already the size of the output.
All 4 causes checked. Contact HP Customer Support.
Service
If the checks above do not clear it, contact HP Customer Support, hp.com/support. Telephone numbers by country are on the flyer in the box or at www.hp.com/support. Source: Customer support, p. 125
Other M234dw problems
- Printer does not pick up paperTray settings, paper or the pickup roller.
- Printer feeds more than one sheet at a timeStack condition, paper type or overfilled tray.
- Frequent or recurring paper jamsFrequent or recurring paper jams.
- Paper jam5 causes in the manual. First: er/04: jam in the input tray or printer base.
- Whole page prints light or fadedWhole page prints light or faded
- Gray background or darker print than expectedGray background or darker print than expected
- Pages come out completely blankPages come out completely blank
- Whole page prints blackWhole page prints black
- Repeating bands down the page in filled areasRepeating bands down the page in filled areas
- Vertical streaks on the printed page2 causes in the manual. First: light vertical streaks in filled areas only.
- Shadow copies of the image repeat down the pageShadow copies of the image repeat down the page
- Toner smears or rubs off at the page edgesToner smears or rubs off at the page edges
- Printout is crooked or not centeredPrintout is crooked or not centered
- Paper comes out curled2 causes in the manual. First: positive curl: edges curl toward the printed side.
- Output stacks unevenly or falls off the trayOutput stacks unevenly or falls off the tray
- Background shading, dark vertical bands or repeating horizontal bandingBackground shading, dark vertical bands or repeating horizontal banding
- Toner specks, spatter, smears, lines or repeating marksToner specks, spatter, smears, lines or repeating marks
- Printer will not connect to Wi-FiPower, radio, SSID or security information.
- Printer does not print after wireless setup is done2 causes in the manual. First: printer state, firewall, network or computer.
- Wireless connection broke after moving the router or printerThe printer and the computer ended up on different networks.
- Cannot add more devices over Wi-Fi DirectRange, user limit, firewall or network.
- Wireless printer drops while connected to a VPNA computer cannot normally join a VPN and other networks together.
- Wi-Fi network is missing from the wireless networks listRouter power, hidden network, range or stale list.
- Wireless network is not functioningThe network lost communication, or the devices use different networks.
- Ethernet connection is not workingNetwork, cable, security software or driver.
Sources
- User Guide, HP LaserJet MFP M232-M237 series. HP Development Company, L.P. Document c06759742, revision UG_EN (PDF created 2020-12-02), 154 pages, en. h10032.www1.hp.com (PDF). Retrieved 13 November 2026.
Page numbers are the numbers printed in the manual. Where this page and the manual differ, follow the manual.