Hi hardhat,
Please try these steps:
1. Click on the Apple in the upper left hand corner and then System Preferences.
2. Click on Printers & Scanners.
3. Click on the TR8520 on the left side and then [-] at the bottom to remove it. Repeat until all TR8520's are gone.
4. On your TR8520, please select the gear icon at the bottom of the display of the printer.
5. Select Settings.
6. Select Device settings.
7. Select LAN settings.
8. Select Common settings.
9. Select TCP/IP settings.
10. Select IPv6 and then Yes.
11. Select Enable/disable IPv6 and select Disable.
12. Press the Home icon in the upper left corner.
13. Turn your PIXMA TR8520 off.
14. Disconnect the power cord to your router. Wait 5 seconds and then reconnect the power cord.
15. When the router is back online, please turn your PIXMA TR8520 on.
16. In the Printer's window on your Mac, click the [+] at the bottom and then click on Add printer or scanner.
17. In the Add window, click 1 time on the TR8500 that appears.
18. At the bottom, next to "Use", select Airprint from the drop down box.
19. Click Add.
20. The printer will set up. Once it is, please click on it 1 time on the left side.
21. On the right side, click Scan and then Open Scanner.
22. When Image Capture opens, please attempt to scan.
If you are able to scan with Image Capture, please open the IJ Scan Utility and attempt to scan with that application.
