RC-1010 not picking up channels

[millergd]

I bought an RC-1010 in November 2010 and am finally getting around to testing it for the first time.

On my Panasonic Viera with a built-in ATSC decoder, I can get all 5 local channels without issue.

On my RC-1010, I can only get one channel (which is not even the strongest channel), and the Manual Edit does not recognize them. I have tried the following:
(1) Bypassing the splitter (eliminating the -3.5dBm signal attenuation), it can still only recognize one signal
(2) Trying the Viera on the coax going into the RC-1010. It still could receive all 5 channels, with most channels being 60-70% signal strength on a cloudy day.
(3) Unplugging and replugging the Winegard system repeatedly.
(4) Adding a CM7777 preamplifier
(5) Adding one of those Home Depot $11 RCA active video amplifiers

My RC-1010 information:
Model ZAT2006HD
S/W: ZAT600HD4007A021

Suggestions? I'm running out of paths to explore...

Thanks,
--Geoff Miller
Ottawa Canada