An RMA should not be necessary. If there was a previous configuration that is causing issues, you can create a USB bootable thumbdrive and re-image the appliance.
Creating a Bootable USB Thumbdrive:
http://support.f5.com/kb/en-us/products/big-ip_ltm/manuals/product/bigip_getting_started_guide_10_1_0/bip_gs_app_thumbdrive.html?sr=22475054
If you are on certain versions and the AoM baud rate does not match the baud rate of the appliance you can have issues:
http://support.f5.com/kb/en-us/solutions/public/10000/800/sol10834.html?sr=22474114
Regards,
Eric