Stuck in lockout mode

Push the "L/O" lockout button and it will lockout that channel.
When you press "Scan" you have to have at least one of the banks scanning, so press 1, 2, 3,....9, 0 whatever bank you have channels programmed in order to automatically scan. You should be able to press "Manual" to see each channel individually.

There are two methods to reset TVs. The first is simple to do; a Hard Reset. The other is somewhat skilled; is a Factory Reset (System Reset). To make it a hard reset, just unplug the TV from AC mains wall socket, and re-plug it back after 15 minutes or so. If you do this by overnight is better. This procedure will make it a hard reset. If you want to make it a system reset [Factory Reset]; you have to enter its service mode option, and select the factory reset option. If you wish to get some details; check the site linked here. Pull up older posts.
http://electronicshelponline.blogspot.com/
Service mode entry, adjust and exit procedure to many popular brand TVs are given. Never forget to exit the service mode, after all adjustments have been done.

To program:

Turn on radio.

It will be in scan mode. Press Manual (orange button) to stop scanning.
Press Manual button to step through channels to get to the one you want.
(Or press channel number and then manual button)

If "LockOut" is displayed it means this channel isn't being "Scanned."
Pressing Lockout will toggle the status.

To program:

Select channel. Use keypad to enter frequency. Use "E" for Enter
key. If the radio displays an E this means Error. Usually, the
frequency you typed in is outside of the capabilities of the scanner.

Once you hit the E you will immediately start hearing anything that's
out there on the frequency you entered.

Push the "Review" button and the scanner will display the frequency
that is programmed for the channel. A "-" will be displayed for the
decimal point.

Programming a frequency into a channel clears the previous channel entry, so there's really no need to "clear" the scanner for reprogramming. To eliminate an unwanted frequency, you can either press the LOCKOUT key to prevent the scanner from stopping on a specific channel, or you can "zero" a channel:

1. Press SCAN/MAN to stop
scanning.
2. Use the number keys to enter
the channel number (1-200)
you want to clear.
3. Press PGM. F=C appears.
4. Press 0 then ENT. The
frequency number changes to
000.0000 to indicate the
channel is cleared.

Need the manual for your scanner? You can download/print it here:

http://support.radioshack.com/support_electronics/doc69/69887.pdf

There is no need to clear the scanner before reprogramming. When you enter a new frequency it will automatically overwrite the old frequency. To clear unwanted frequencies you can program "0.0" into any channel to clear it, or simply use the LOCKOUT feature to prevent the scanner from stopping on a channel.

Hi,
Try these instructions from Wiki.answers

Turn on unit.
Press MANUAL button.
Press MANUAL button again to select the channel you want to program. Note the channel in the display. If there is a hyphenated symbol in the upper left corner the channel has been locked out. Press the LOCKOUT button once to remove the symbol or press the LOCKOUT button to lock a channel out. To find out if there is a frequency programed into that channel, press the PREVIEW button. Each digit of the frequency that is stored in memory will be displayed in the LED display. To program a new frequency into that channel, simply press the digits of the frequency you want, including the decimal point. Press the "E" keypad key to enter it into memory. If you get a "E" displayed in the LED display, the frequency was entered wrong, is not a valid frequency or is out of range for the scanner. Last but least, the scanner is not working properly. If the channel is active, (communications going over it) set SQUELCH to higher number, until you hear the communications or just noise. To set the SQUELCH, select a channel that has only noise and turn it down to the point the noise disappears. You make have to readjust it to your liking. Once you have the channels programed you can select the SCAN button to listen to all the channels or select the MANUAL button to listen to just one channel. If there are channels that you don't want to hear during the scan mode, go to MANUAL and select the channel you don't want to hear and press LOCKOUT button. Then press SCAN again it will only scan channels you want to hear.

Hope this helps.

Sounds like old age - the 2020 is nearly 30 years old! Have you tried just using the LOCKOUT feature on all channels except the you want? How about just programming the same frequency into all 20 channels?

While in SCAN mode, enter the number of the channel you want to lockout. To re-activate it, enter the channel number again.

Ok doc, I'll see if I can walk you thru this as there don't seem to be a manual available for download.
* Push manual button and bring it around to channel #1
Enter the freq including the decimal point. Push the E button to enter the freq into the first channel.
* Push manual again and move to channel #2 and repeat.
If you need some new freq's for your area, go here, click on your state, county, and it'll give you a complete rundown.
http://www.radioreference.com/apps/db/

If you need 10 codes for your area, go here and click on your state.
http://www.nat-com.org/radio.htm
If you need anything else, let us know,, Mechanic