@Mazzoladm 

 A few things:

I assume you tried connecting this way?

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Once you set up the Canon Pixma TS8120 Wireless Inkjet Printer, you can connect it to your wireless network by following the steps mentioned under:

1. Turn on your printer and ensure that the power LED is lit.
2. Tap on the Home icon on the printer’s control panel and select LAN Settings.
3. Tap on Wireless LAN and then on Wireless LAN setup.
4. On the next screen, select the “Easy wireless connect” option and then tap on Yes.
5. Run the downloaded printer setup file and select Start setup on the initial screen.
6. Select your country and tap Next.
7. Read the License Agreement and if you agree to it, click on Yes.
8. Go through the survey and select Agree or Do Not Agree.
9. Select Next and then tap on Yes.
10. Locate your router SSID and enter your network password in the requested field. You have now successfully connected the Canon Pixma TS8120 Wireless Inkjet Printer to WiFi.

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I also assume the printer was connected to the OLD router?

Two problems that might be a reason:

1. The Printer just can't work with the higher level Security?
2. The Printer might have the old router information stored in it?

For #1 I'd test setting the Router SSID security to NONE or one that matches the Printer one that it uses.

For #2 I'd try resetting the Printer (if that is possible) to erase anything it has stored in memory?

I'll assume the Printer is not showing connected? If it is the PC, then it might have the wrong (a different) IP Address for the Printer. If so, delete the PRINTER on the PC and ADD a Printer, might fix it?

All suggestions to try, I might be way off base here.