Printer troubleshooting

This guide fixes the common printer problems, from "nothing prints" to strange characters and blank slips. First rule during service: keep cooking from the kitchen display. Nothing is lost while a printer is down; prints wait in the queue. Most checks below are in Settings → Printing & screens (owners and managers) and on the Print station page.

Nothing prints, or jobs just say "Waiting"

Open Settings → Printing & screens and look at the printer cards and Recent prints. Each card says in words whether its AirQR Printer Helper or print station is online. (The printer itself can't report that it is switched on, so use Print test page.) The list of stations is under Advanced: print stations and bridges, and in Settings → Devices.

1. Is the printer's station online? Every print is done by a print station: a Print station browser tab (for USB, Bluetooth, serial and print-dialog printers) or a AirQR Printer Helper (for LAN / Wi-Fi and computer printers). On each printer card, and in Devices, a green dot means online and grey means offline. A station counts as online if it checked in within the last minute or so.
2. Browser tab offline? Someone closed the Print station tab, the tablet went to sleep, or the browser is in the background. Open Print station on that device again and keep it in front.
3. AirQR Printer Helper offline? The Helper program isn't running, the computer is off or asleep, or it has no internet. Start it again with node airqr-print-bridge.mjs on that computer, and set it to start with the computer (see Set up a LAN / Wi-Fi printer and the AirQR Printer Helper).
4. Printer says "Not connected — jobs wait in the queue until you connect it" on the print station? Press Connect USB, Connect Bluetooth or Connect port (or Reconnect).
5. Print station shows Paused? Press Resume.
6. Printer shows "Off" in settings? Edit it and switch Printer is on back on.
7. Auto-print off? A printer marked manual only prints only when someone presses Print. Edit it and turn the auto-print switch on.
8. Check paper, power and cable/Wi-Fi on the printer itself.

Once fixed, prints under 30 minutes old come out by themselves. Older ones show as Missed; see the last section.

Print bill says "No printer is connected"

Print bill never opens a page or a print window by itself. This message means the outlet has no active bill printer (or its plan has no printing). Press Set up printer (Settings → Printing & screens → Add printer), or Open bill to see the bill on screen. "Sent — waiting for (computer) to come online" means the printer is set up but its computer (or print station tab) is offline: start the AirQR Printer Helper or open the Print station, and the bill prints.

A LAN / Wi-Fi printer won't print (refused or timeout)

The error shows under the job in Recent prints, and in the AirQR Printer Helper's window.

• "Can't reach the printer at (IP) — is it on, and on the same network?" (a timeout): the printer is off, its IP has changed, or it's on a different network or Wi-Fi than the Helper computer. Print a self-test page (switch off, hold FEED, switch on) and compare the IP with the one in AirQR. The Helper computer and printer must be on the same network (e.g. both 192.168.1.x). Reserve the printer's IP in your router so it doesn't change again.
• "Printer at (IP) refused port 9100": something answered at that IP but not on the print port. Check the IP isn't another device, and check the printer's network settings for its RAW / JetDirect port (usually 9100). If it's different, add it to the address, e.g. 192.168.1.87:9100.
• Test from the Helper computer: run node airqr-print-bridge.mjs --test 192.168.1.87 (your printer's IP). If this prints, the printer and network are fine and the problem is in AirQR's settings.
• "The Helper token was rejected": the Helper was removed or given a new token. In Print stations, create a new token (or add a new bridge) and run the new command.
• Windows "The network name cannot be found" (Computer printer): the printer isn't shared, or the share name in AirQR is wrong. Check Printer properties → Sharing.

A USB, Bluetooth or serial printer won't connect

Quickest way out: in the Add printer wizard, every connection error offers Use it through the Printer Helper (automatic) first, and Use the print window (not automatic) as a last resort. Copy error details copies a short report you can send to support.

"The browser can't open this printer" on a Mac: your Mac or another app is using the printer. Quit other printing or POS apps, unplug the printer and plug it back in, then press Find printer again. If the printer is added in System Settings → Printers & Scanners, macOS holds it: use it through the AirQR Printer Helper instead (it prints automatically with the Mac's driver).

"Bluetooth is off or not available": turn Bluetooth on (and on Android also Location) and try again.

"The browser isn't allowed to use Bluetooth" on a Mac: System Settings → Privacy & Security → Bluetooth → turn on Google Chrome, then quit and reopen Chrome.

Bluetooth printer not in the list: many printers use classic Bluetooth, which browsers can't see. Pair it in the computer's Bluetooth settings and choose Serial / COM port in the wizard, or use Installed on this computer.

USB printer not in the list, or "Couldn't open the USB printer" / "The USB printer is in use by another program or driver" (Windows): Windows' own printer driver holds the printer, so Chrome can't use it. Best fix: add the printer as Computer printer and use the AirQR Printer Helper on that PC. Alternatively replace the driver with WinUSB using Zadig (then the printer prints only from AirQR). Also close other billing or print apps that may be using it.

USB printer not listed (any computer): press Printer not listed? to see every USB device. Try another cable or port. On Android, use a USB-OTG cable.

"This USB device has no printer output": you picked the wrong device. Choose the receipt printer.

Bluetooth "doesn't offer a Bluetooth LE print service": the printer is classic Bluetooth only, and Chrome can only use Bluetooth LE printers. Pair it to a Windows PC or Mac in the computer's Bluetooth settings, note its COM port, and add it in AirQR as Serial / COM at 9600 baud. On Android, use a BLE-capable printer instead.

"Couldn't connect to (printer)… Is it on, charged and close by? Unpair it from other phones first." Charge it, bring it near, and remove it from other phones' Bluetooth lists. Don't pair it in Android settings; let the print station find it. On Android, Bluetooth and Location must both be on.

"Couldn't open the serial port… Is another program (or tab) using it?" Close other programs or AirQR tabs using that COM port, then press Reconnect.

"This browser can't use … printers" or "This page needs HTTPS": use Chrome or Edge (Chrome on Android for Bluetooth), and open AirQR on its https:// address. iPhone, iPad, Safari and Firefox can't connect to these printers; use a LAN printer with the Helper or the Print dialog connection.

It prints garbage, Chinese characters or random symbols

AirQR sends standard ESC/POS commands. On every print it switches off the printer's Chinese character mode and selects the standard code page (PC437). If you still get garbage:

1. The printer isn't in ESC/POS mode. Some printers can emulate other command sets. Use the maker's utility (or the printer's setup buttons, per its manual) to set ESC/POS mode and code page PC437.
2. Wrong baud rate on a serial printer. Serial printers print random characters if the speed doesn't match. On the Print station, press Disconnect, choose the right Baud rate (9600 is most common; try 19200, 38400, 57600 or 115200), and press Connect port again. The printer's self-test page often shows its baud rate.
3. It isn't an ESC/POS receipt printer (for example a label printer or an A4 inkjet or laser printer). For an ordinary paper printer, add it as Installed on this computer and set Paper type to Regular paper (A4/Letter): the AirQR Printer Helper then prints the bill as plain text with the printer's own driver. (The AirQR Printer Helper must be version 1.2.0 or newer; download it again from Settings → Printing if the job fails.)

Hindi or regional item names print as "???": thermal printers can't print those scripts in text mode. AirQR prints the item's English base name when one exists, so keep an English name on every item, add-on and size. To print regional scripts on paper, use the Print dialog connection.

₹ prints as "Rs.": this is on purpose; most thermal printers can't print the rupee sign.

Text is cut off, wraps badly, or is too narrow

The Paper width in AirQR doesn't match the printer. A 58 mm (2 inch) roll fits 32 characters a line; an 80 mm (3 inch) roll fits 48.

1. Edit the printer in Settings → Printing & screens and set Paper width to match the roll: text cut off or wrapping on every line means you chose 80 mm on a 58 mm printer; everything squashed into the left side means 58 mm on an 80 mm printer.
2. Press Test. The ruler line on the test page should fit exactly on one line.
3. You can check before printing with the printer's … menu → Preview test page.

For bills and tickets printed through the browser (Print buttons, print dialog), the Paper width under Receipt layout on the same page also has to match.

KOT printed in the wrong section, or printed twice

KOT in the wrong section (e.g. drinks on the kitchen printer):

• Check the dish's station: Menu builder → the item → Send to station.
• Check the printer's Kitchen stations: All stations prints everything. A bar printer should have only bar.
• "Nothing to print on this printer" or "None of the recent tickets have items for this printer's stations" means that printer's stations don't match any items; that's expected for, say, a bar printer on a food-only order.

Double prints:

• Two KOT printers both set to All stations, or with the same station ticked, both print the same items. Give each printer its own stations.
• Copies is set to 2 or more on the printer.
• A bill that printed on settle and was then printed with Print bill gives a second copy marked (DUPLICATE). That's expected.
• Two kitchen display screens with Print tickets from the kitchen display (opens a print window) on (only used when no KOT printer is set up) each print every ticket. Use it on one screen only, or set up a KOT printer.
• The same printer added twice in settings. Delete the extra one.

Blank paper, or the cash drawer doesn't open

Paper comes out blank: the thermal paper roll is in upside down. Thermal paper only prints on one side. Scratch the paper with a fingernail: the side that turns dark must face the print head. Flip the roll and press Test. Also check the roll is thermal paper, not plain paper, and the printer's lid is fully closed.

Cash drawer doesn't open:

1. The drawer must be plugged into the bill printer's drawer port (RJ11 cable), not the computer.
2. On that printer, turn on Open the cash drawer in Settings → Printing & screens.
3. The drawer opens only when a bill prints automatically on settling a check with a cash payment, or on the printer's Test page. Print bill pressed by hand, and card/UPI bills, don't open it.
4. Press Test: the page says "(cash drawer should open)". If it prints but the drawer stays shut, check the cable, the drawer's key/lock, and that the drawer suits your printer.

Failed or missed prints: reading Recent prints and reprinting

Settings → Printing & screens → Recent prints lists the last 40 prints from the past 3 days, with the time, the print (e.g. "KOT #3044"), the printer and station, and the status:

"The print station stopped responding while printing" means the tab or bridge went away mid-print (tab closed, computer slept).

To reprint: fix the cause, then press Print on a failed or missed job. Press Again on a printed one for another copy. Use the eye icon (Preview) to see exactly what was sent. On the kitchen display, the printer icon on a ticket also reprints its KOT, marked REPRINT. On the print station, failed prints in Activity have a Print again button.

Still stuck? Call or WhatsApp +91 96573 22724 or email support@airqr.in with the printer model, the connection type and the error shown in Recent prints.

"Printer not found" or the wizard finds nothing

• Wi-Fi or network printer: switch it on, check that it is on the same Wi-Fi or router as the Helper computer (not a guest network or another VLAN), and press Scan again. The Helper looks at port 9100 on its own private network. If it still isn't listed, hold FEED while switching the printer on to print its IP address and use Enter an IP address.
• "Find printers" says the Helper is an older version: download the newest airqr-print-bridge.mjs from Settings → Printing & screens → Advanced and restart the Helper.
• Installed printer missing from the list: add it to that computer first (it must show in Windows Printers & scanners, or lpstat -e on Mac and Linux), then Scan again. On Windows the printer must also be shared with the same name.
• USB or Bluetooth: Find printer shows an empty list or "access denied": use Chrome or Edge on the computer the printer is connected to. On Windows USB, either install the WinUSB driver with Zadig or choose Printer already installed on a computer in the wizard.
• The test page doesn't print but the printer was saved: the wizard says why. Fix it, then press Try the test page again, or Print test page on the printer's card.