HP DeskJet 4155e Wireless All-in-One Printer with Mobile Printing and 4800 x 1200 dpi Color Resolution MECH-04 Error Fix: Wireless Connection Drops or Printer Goes Offline

Error code MECH-04 on the HP DeskJet 4155e Wireless All-in-One Printer with Mobile Printing and 4800 x 1200 dpi Color Resolution means: Wireless Connection Drops or Printer Goes Offline. The printer loses its Wi-Fi connection and appears offline on computers and mobile devices — this is the most common connectivity complaint for HP wireless printers; ensure the printer is within range of the Wi-Fi router (ideally in the same room or within 30 feet with line of sight); the printer and device must be on the same Wi-Fi network (same SSID and frequency band); restart the printer, router, and device; on the printer, use the Wireless Setup Wizard to reconnect; the HP Smart app can diagnose and fix most connectivity issues; some routers with band steering (combined 2.4/5 GHz) can cause issues — try setting a dedicated 2.4 GHz SSID for the printer

The most successful fix is "Replace Worn Imaging Drum via Cartridge Replacement" (medium difficulty, ~30 minutes). Estimated DIY cost: $100-$120. HomeMD has 2 community-ranked fixes for this error.

This error is rated medium severity. It should be addressed soon, but your appliance may still function in a limited capacity.

Yes — the top-ranked community fix ("Replace Worn Imaging Drum via Cartridge Replacement") is rated medium difficulty and takes about 30 minutes. Tools needed: .

DIY cost: $100-$120. Professional repair typically costs $150-$220. Many homeowners save money by trying the top-ranked community fix first.

The HP DeskJet 4155e Wireless All-in-One Printer with Mobile Printing and 4800 x 1200 dpi Color Resolution has 8 other known error codes, including: E0 (Cartridge Access Door Open), E1 (No Paper in Input Tray), E2 (Paper Size Mismatch), E3 (Carriage Jam), E4 (Paper Jam), and 3 more.

Error code MECH-04 also appears on 7 other HP models: ENVY 6055e All-in-One Wireless Printer with Auto 2-Sided Printing and Smart App Integration, HP Color LaserJet Pro M255dw Wireless Color Laser Printer with Auto Duplex Printing and 22 ppm, HP OfficeJet Pro 9015e All-in-One Wireless Inkjet Printer with Auto 2-Sided Printing, 35-Page ADF, Fax, and 22 ppm, HP Smart Tank 7001 All-in-One Wireless Ink Tank Printer with Auto Duplex, ADF, and Refillable Ink System, LaserJet M209dw Mono Wireless Printer with 30 ppm Print Speed and 1200 x 1200 dpi Resolution, LaserJet Pro M404dn Mono Laser Printer with 40 ppm, Ethernet, and Duplex Printing, and 1 more. The fix may vary by model, so check each model's specific page for tailored repair steps.