Can you be more specific. Do you mean the scanner won't power up, or do you mean it says "Scan mode: nothing to scan." If it says the "Nothing to scan" go to menu, scroll down to "weather," then press "weather scan" and see if you have anything. If you do, then you know the unit is working (antenna is connected, etc).
The most common reasons for geting a "scan mode: nothing to scan" screen is 1) the database or favorite lists in the Set Scan Selection are turned "off," 2) the "Select Service Types" are not on, or the ones are not "on" for the channels you have programmed, and/or 3) the "quick keys" are off.
Is your SD card OK and able to be written to Sentinel software?
Please be more specific about what you did between the time it worked and did not work, and I'm sure some of us will be able to steer you in the right direction.
That's always a good, quick and easy diagnostic to determine if a scanner is receiving.
If you receive weather, then your scanner is receiving and the problem is most likely a programming issue due to an inadvertent button press. You'd have to get Sentinel going and carefully review everything. There are numerous settings and any one of them could be incorrect which causes a problem.
If you don't get weather it may be an antenna issue, particularly if you have an external antenna. If you are using the stock antenna, remove and re-attach it.
The worst case scenario, which happens rarely, is the "front end" of the scanner is blown. This can happen if a transmitter has been keyed up very close to the scanner. (By close I mean transmitter antenna and scanner antenna being within a couple of feet of each other).
It says that is is ID scanning on my Dept I programed in it but it is not picking up anything, I changed the antenna with my BCD996XT and it still wont work but the antenna from the BCD536HP works on the 996XT. I also did a weather scan and it has not picked up anything so idk what is wrong with it I've only had it less than 2 months, I guess I will send it back and see if they can fix it!
Is it possible that a different location has been set in the scanner, and the scanner "thinks" it's in a different location than where the system is, and thereby not properly scanning the correct site's control channels? Not sure that would be the problem, since it's not even picking up any weather channels, but I figure it's worth a shot to see.
I would bet you have the service tags disabled. I was under the impression initially that they only controlled the nationwide database but in fact they control the scanning of the favorites lists, too.