Printer or device offline after changing the router, the Wi-Fi password or the internet provider - how to reconnect them

Applies to Invu POS 6.10.6 on iPad, Android and Windows, and to the Admin Panel. Labels are shown as they appear when the POS or the panel is in English. If you do not know yet which printer fails, or the problem is not the network, start with "The printer does not print kitchen tickets or invoices - how to check it".

The most important:

• The POS prints over the local network: the iPad (or device) and the printer must be on the same network. If someone changed the router, the Wi-Fi password or the internet provider, one of them usually ended up on another network or with another IP.
• First move the iPad to the right network. Then find the printer in Troubleshoot and, if its IP changed, assign the new one.
• Do not press the reset button on the printer or the router: it erases their settings and makes the problem longer.

1. What happened: common reasons the printer shows in red

2. Put the iPad on the right network

1. On the iPad, open Settings > Wi-Fi and check which network it is on. It must be the same network as the printers: usually the main network of the store, not the guest one.
2. If you changed the password, tap the network, choose Forget This Network and join again with the new password.
3. If the iPad has a SIM, remember that on mobile data it has internet but cannot see the printers.
4. In Settings > Invu POS, check that Local Network is on. See "Activacion de Red Local, Invu POS API en Verde, Equipos en Rojo." (local network permission).
5. On Android or Windows, check the same in the device's Wi-Fi or network settings.

Then, in Invu POS, press and hold the Invu logo and choose Troubleshoot. The This POS network card shows the network and the IP of the device, for example "IP 192.168.1.35". Write down the first three numbers (192.168.1): the printer's IP must start the same way.

3. Find the printer's IP (self-test page)

Almost all thermal printers print a self-test page with their network settings:

1. Turn the printer off.
2. Press and hold the paper feed button (FEED) and, without releasing it, turn the printer on.
3. Release it when it starts printing. Look for the IP (IP Address) on the page.

The procedure can vary by model; if nothing prints, check your printer's manual or write to us.

Compare that IP with the POS IP:

• They start the same (192.168.1.35 and 192.168.1.50): same network. Go on to section 4.
• They start differently (192.168.1.35 and 192.168.0.50): the printer has a fixed IP from the previous network, usually because the router or provider changed. Find printers will not find it: it only scans the POS network. The IP has to be changed on the printer, or the new router set to the old numbering. Whoever manages your network or support does this (section 6).
• The page shows 0.0.0.0 or no IP: the printer is not getting a network. Check the cable or, for Wi-Fi, that it knows the new password (section 5).

4. Find the printer and assign its new IP

In Troubleshoot, section Printers and peripherals:

1. Tap Find printers. The POS scans the network and shows the Detected devices.
   • If you see "Could not scan the local network. Check network permission or enter an IP manually.", check the Local Network permission (section 2).
   • If you already know the IP (from the self-test page), type it in Check IP.
2. Choose the device and tap Print test. A PRINT TEST ticket should come out. This confirms which physical printer it is.
3. Tap Assign to INVU and choose which Invu printer it is (for example, "Kitchen"). Check the previous and new IP and tap Save.
4. On the other devices, press and hold the Invu logo and tap Update Data.

You can also tap Edit on a kitchen printer row and type the new IP, or change it in the Admin Panel: Printers > Printer List > Edit Printer, field IP.

• Saving the new IP needs internet, because the change is stored on the server.
• The pre-check IP and the Raspberry (fiscal printer) IP are not changed in Troubleshoot. In the panel, go to Cash Register > Cash Register List, edit the register and change Pre-account IP or Raspberry IP. Then do Update Data.

5. Wi-Fi and wired printers

• Wi-Fi printer: if you changed the Wi-Fi password or name, the printer does not reconnect on its own. The new network has to be set on it with the manufacturer's tool. If you do not know how, write to us. Meanwhile, you can temporarily put the old password back on the router.
• Wired printer: the cable must go to the router or switch of the same network as the iPad. If the router was replaced, move the cable to the new one. Check that the lights on the printer's network port are on or blinking.

6. The printer disconnects now and then

If it sometimes prints and sometimes shows Offline or "Error in following printers":

• The IP changes by itself: the router gives it another IP each time it restarts. Ask whoever manages your network for a fixed or reserved IP for each printer and for the Raspberry.
• Two devices with the same IP: if another device took the printer's IP, both fail now and then. A reserved IP solves this too.
• Damaged cable or connector, or a switch without stable power: replace the cable and try another port.
• Weak Wi-Fi signal: move the printer or the iPad closer to the router or access point, or switch it to cable.
• The iPad jumps between two networks (for example, the store's and the guest one): in Settings > Wi-Fi, open the wrong network and turn off Auto-Join, or forget it.

7. Red bar or "Invu Cloud Services" offline

That is internet, not the printer. Network printers keep printing without internet if they are on the same network as the iPad. Do not move the iPad to another network "that does have internet" if the printers are not on it: you will have internet, but printing will stop. See "Invu's network and router - what to do if there is no internet or the network does not show up".

When to contact support

Write to us if the printer has an IP from another network, if it is a Wi-Fi printer and you do not know how to set the new password, or if it is still red after these steps. Send:

• A photo of Troubleshoot (with the This POS network card visible).
• A photo of the printer's self-test page.
• What changed and when: router, Wi-Fi password, provider or power cut.