POS Troubleshooting Cheatsheet
POS Troubleshooting Cheatsheet
Quick-reference symptom ߆’ cause ߆’ fix for the most common POS failures.
Receipt Printer
| Not printing | Check IP in POS config; print self-test page to confirm printer IP |
| Faded print | Clean thermal head with IPA on cotton swab |
| Paper jam | Remove roll; clear debris; ensure correct roll width (58 or 80 mm) |
| Prints garbage | Wrong baud rate (serial) or wrong code page ߀” match settings in POS software |
| Beeps, no print | Paper out or cover not fully closed ߀” check and power-cycle |
Cash Drawer & Scanner
| Drawer does not open | Check cable is in DK port (not phone socket); verify POS sends open command |
| Drawer opens slowly | Worn spring ߀” replace spring or full drawer assembly |
| Scanner beeps, no input | Wrong field focused (HID mode) ߀” click into barcode entry field first |
| Wrong characters scanned | Keyboard layout mismatch ߀” program scanner to match OS layout |
| Wireless scanner drops | Low battery or out of range ߀” charge base, move closer |
Card Terminal
| Connection failed / timeout | Check port 443 outbound; verify DNS; check cable and switch port |
| Stuck on Connecting | IP conflict or wrong gateway ߀” verify static IP settings |
| Chip card not reading | Dirty reader ߀” clean with chip cleaner card |
| Contactless not working | NFC disabled in settings or faulty antenna |
| Application error / white screen | Power-cycle; contact acquirer if persistent |