Line not assigned

The "CO Not Assigned" error on your Panasonic KX-T7433 handset indicates that the Central Office (CO) line has not been properly assigned to the handset. Since you've mentioned that other handsets in your office can connect to CO-01 without any issues, the problem seems to be specific to certain handsets. Here are a few steps you can take to troubleshoot and potentially resolve this issue:

1. Restart the Handset: Sometimes, a simple restart can resolve temporary glitches. Try unplugging the handset's power cord for a few seconds and then plugging it back in.
2. Check CO Assignment: Double-check the CO assignment settings on the problematic handsets. Make sure that the CO-01 line is correctly assigned to those handsets. Follow these steps:
   • Press the "Program" button on the handset.
   • Dial 1 (CO Line Access).
   • Dial the line number you want to assign (in your case, 01).
   • Press the "Auto Dial/Store" button to save the assignment.
   • Hang up the handset.
3. Reset the Handset: If reassignment doesn't work, you can try resetting the handset to its default settings. Keep in mind that this will erase any customized settings on the handset. To perform a reset:
   • Make sure the handset is not in use.
   • Press and hold the "Program" button while you reconnect the power cord.
   • Keep holding the "Program" button until the handset displays "Initializing..." and then release the button.
   • The handset will restart and return to its default settings. You'll need to reconfigure any personalized settings afterward.
4. Firmware Update: Check if there are any firmware updates available for the Panasonic KX-T7433 system. Outdated firmware can sometimes cause compatibility issues. Refer to the user manual or Panasonic's official website for instructions on updating the firmware.
5. Contact Panasonic Support: If none of the above steps resolve the issue, it might be best to contact Panasonic's customer support. They can provide specific guidance based on your model and system setup.
6. Physical Check: Ensure that the physical connections and cables related to the CO-01 line are secure and functioning properly. A loose connection could lead to communication problems.

Keep in mind that these steps are general suggestions and may need to be adjusted based on the specific model of your phone system and any unique configurations in your office. If you're not comfortable performing these steps yourself, it's recommended to seek assistance from a professional technician or the manufacturer's support team.

Suggest you reset handset and register again with base.

Instructions from manual...
Resetting Handsets If you have trouble with a handset or if you want to replace one, clear the registration information from the base and the handset: 1. Press & hold END and # at the same time until you see the System Reset menu. 2.If you still have the base the handset is registered to, select Deregister HS, then select the handset you want to reset. If you don't have that base anymore, select Base Unavailable. 3. To confirm, select Yes. The handset displays Handset not registered. Registering Handsets If you see a "not registered" message on a handset, you must register it to a base before using it. 1. Place the handset in the base; the display should say Handset Registering. 2.Wait until the display says Registration Complete (about 30 seconds), then pick up the handset and press TALK/FLASH. 3.If you don't hear a dial tone or the display says Registration Failed, charge the battery completely, then try again.

1. Press & hold End and # at the same time until you see the System Reset menu.

2. If you still have the base the handset is registered to, select Deregister HS, then select the handset you want to reset. If you don't have that base anymore, select Base Unavailable.

3. To confirm, select Yes. The handset displays "Handset not registered"


Now you want to register the phone again.

1. Place the handset in the base; the display should say Handset
Registering.

2. Wait until the display says Registration Complete (about 30
seconds), then pick up the handset and press Talk/flash.
You should now have a dial tone

I don't know about a handset, since mine doesn't have a dial, but the phone underneath the handset has to have a button programmed with the lines you use in order to work. By default, the system has some number of Single CO buttons assigned in numerical order from the bottom to the top and left to right. You can test that by pressing PROGRAM, press the line buttons in sequence, and reading the display. They will say CO 001, 002, 003 etc. If they don't, you can always dial 0 001 store, 0 002 store etc and get the line appearance back.

This solution works in a small system and is very basic. It doesn't take a T1/E1/PRI or group CO buttons. into consideration. Such a solution is beyond the scope of a free forum.

Carl

So don't pick up the handset :-)

There are some line preference and pickup dial programs that just happen to sit in PROGRAM 1x. My guess is that you have assigned an empty or invalid pickup dial code to the phone.

Try this first. Press PROGRAM and dial 12 ENTER. Is the Hot Line mode ON? If it is, press SEL and ENTER. Wow. That was easy :-)

Didn't work? Let's go for Preferred Line Outgoing next. Dial PROGRAM 19 and 3 ENTER. That makes the intercom prime (0 is none, 1 is idle line 2 (xx) is a specific line).

If you tried both of these, and still no joy, then it's time to reset the phone. The problem with that is you have to dial the code IMMEDIATELY as you're picking up the handset. Good luck with that. The reset code is 79# or 790.

Carl

Please try this first (Reset the phone which requires the ringer to operate again with the main base) Some Panasonic cordless phones come with up to five handsets each will need to be properly adjusted. You may need to set the main handset to synchronize with the base unit plugged into the telephone wall jack and assign special configuration numbers to the other handsets in order to properly identify each one within a specified location. One handset left in the turned on mode may make it impossible to place calls with the any of the other handsets. This will continue until either the battery dies or fails on the handset or the phone is switched off and replaced in its charger for charging again. Synchronize the main handset by pressing the MENU button on the handset, then pressing the down button IN order to select the number you wish to assign to that handset. Repeating this process if you have already done so will greatly decrease the level of errors experienced with panasonic phone

Actually, you have a Panasonic TD phone system and a 7420 phone, but no matter. The feature you have is probably "idle line preference" or "preferred Line Assignment-Outgoing". In TD systems by default, you select lines from highest to lowest. If you only have 2 lines and PLA is set, you get line 2 then line 1. You can change it to get line 1 first, or chage the trunk access order. The first is something you can do from each phone, the second requires access to system programming. The bad thing about the first solution is if line 1 is busy, you won't get any line. The second will give you the entire trunk group.

Anyway, from each phone without picking up the handset, press PROGRAM 99 and dial 1301 STORE. That will give you line 1 when you pick up the handset. Just so you know or can change it, 11 is none, 12 is idle line, 13xx is specific line and 1+the intercom is intercom. Pick up the handset and drop it back down to exit programming.

As far as the noisy line, it's probably a central office issue. It's hard to test as that line is the outer pair of the jack that plugs into the phone sytsem (RJ-14 pair 2), but you can probably take a regular phone and test it at the demarc point.

Carl

I've never heard of the ability to reassign an intercom button as it's a fixed feature, but maybe so. Start by assigning the lower left phone button back to CO1 and let's see what happens. WIthout picking up the handset, press PROG the button and dial 0+01 STORE or ENTER.
Pick up the handset and drop it back in the cradle to exit programming.

Did that work? Making button 1 into CO1 will drop the programming from the intercom button and it should default back to intercom.

Carl

if your phone had set for ringging assignment, u no need to press any key to answer the call.
check the indicator light,
if green light turn on, u can direct answer the call
if red light turn on, u ned to press the line to answer the call
kindly ask the phone provider the set yr extention for incoming ring assignment

Registration:
a. Press MENU-6 to enter the registration mode
b. Press and hold the base’s Registration (REG)
button for 2 seconds until 4 LEDs light up. (Located on the base where you plug in the phone jack)
c. Press handset key “1”, this completes the
registration process. When you register the
handset to BASE 10, the base will assign a
handset ID between 11 and 19. The assigned ID
will be displayed on the handset LCD, indicating
successful registration.
d. Repeat above steps for all additional handsets.
e. The first two handsets registered will be given ID
11 and 12, which gives them administrator
privileges.