Please have it connect to POE switch or a power injector and try to assign an static IP to your PC from 192.168.0.0/24 subnet, then try to ping the AP's default IP 192.168.0.1 if you get any response please go to browser and type the AP's default IP now you should have access to the AP's web interface.
Once you have regained the access to the AP's web interface please upgrade the AP with AP's standalone software please use the link below,https://support.ruckuswireless.com/software/1017-zoneflex-solo-access-point-104-0-0-0-1347-ga-softwa...
Once the AP is added on the vSZ (using option43/dns/l2 discovery/set director/scg ip ) the AP should join the vSZ and upgrade itself to 3.4.x version.
I don't have vSZ on 3.4 version, else I would have given the 3.4.x firmware please try to reach out to support if you have any challenges they would be glad to help you.
Please use this URL from your PC via browser when you have connectivity to vSZ, you should be able to download the firmware from vSZ, not sure if it works now or not.
Hope it helps!!!!