Hi racinjake,
On many models, the antenna wire comes into the bedroom first and feeds the signal booster. The signal booster has several outputs; one that goes to a coax connector into which you plug the bedroom TV. The other output goes to the living room. Often the signal booster is mounted in the ceiling near the TV and there may be two coax connectors; one for the signal booster output and the other for satellite.
You probably know this already, but the signal booster has to be on to receive TV signals, and you have to be connected to the correct coax connector if there's more than one.
As with the living room TV, the TV menu has to be set to AIR or ANTENNA before starting the channel scan.
If you've got all that right, then I'd suggest dropping the signal booster to examine the connectors on the backside. Maybe one of the coax connections is loose or has a short or bad crimp.
A word of caution. The 12V line on the signal booster is pretty easy to short to the coax connectors. You might want to cover it with electrical tape while working on the connectors.