I just bought a brand new LCD with built-in ATSC / QAM / NTSC Tuners and
a indoor Philips VHF/UHF/FM/HDTV 50dB antenna (MANT510) but unable
to get any digital signal at all. I'm not talking about bad signals... it's
no signals.

Anyone here live near Alhambra or East Los Angeles able to get off the
air HDTV to work?

Thanks,

After more adjustments with the antenna... managed to get a few digital
channels.. but no luck with 2.1 and 4.1... :(

Never mind.. got most of the HD channels, I believe.
Need to point the antenna toward to the right direction and run channel search or
for some reason my TV refuse to pick up signal.

Unlike ananlog signals, you will either get or don't get the digital signal. I live in San Gabriel, and get most of the OTA HD channels. You don't really have to aim the antenna directly, but look for Mt. Wilson (up north) that has all the TV station antennas and aim the antenna in that general direction.