Listed following System Test, under Settings. Internal storage device error - says it could be an initialization only or critical fault. Resetting HR does not clear it and unit takes forever to boot back up, but eventually does and can still access recordings, etc. for now. Unit does freeze up from time to time. DirectTV did send out an HR23-700 as a replacement. Does anyone know how these two receivers compare? HD size, etc? They did not want the HR21 back. Will the AM21 OTA tuner work with the HR23? Another option for me is to upgrade to Genie. I have a free upgrade (albeit with a 2 yr. contract) listed on my account. I have just two DVRs now. The HR21 with issues and a older HR20 with an upgraded internal 2 TB HD that I put in a couple of years ago after the old HD died. I like having and use the integral OTA on that one. Thanks in advance for any advice.