WHEN I PLUG IN VERY LITTLE RECEPTION WEATHER BAND COMES IN FINE. SIGNAL DOES NOT MOVE EVEN WHEN KEY MIKE, CAN'T SET SWR VERY DIM EVEN WHEN ADJUST DISPLAY
1st. You cannot "set" the swr. The swr is not set on the radio. The antenna must tuned to attain an appropriate SWR reading.
2nd, If this doesn't solve your problem then you could have a worse problem. If there is a problem with the mic such as a break in one of the wires, the radio's receive will be off until you put a good mic on it. Try a different mic, and see if the receive comes back. Then check and see if your transmitting better.
As well, your meter could just be bad, as well your coax or antenna. Your receive could be poor if the antenna is not tuned to lowest SWR.
If it has been working up till recently, and you have "set" the SWR on the radio, which is not what the SWR function is for, because you don't set SWR on the radio, you could have been using the radio with the SWR super high and blown the final or other sections of the radio out.
SWR is basically signal reflection. If the antenna is not the right length, it will reflect energy back into the radio and damage it over time. The more an antenna is off from the correct length, the more reflect you will get.
The meter in the radio is used to determine how much reflect you are getting. You ideally want to have the lowest SWR possible.
To check the SWR, you set the meter switch to CAL. Key the mic. while holding the mic key down, turn the CAL knob up until the needle is at the little triangle at the top right of the meter marked by "CAL", Then while still holding the key, flip the meter switch to SWR. where ever the needle is at that point is your SWR.
You want ch 20 to have the lowest SWR. If the swr reading on channel 40 is higher then channel 1 then your antenna is too long. if it is higher on 1 then 40, its too short. Make small adjustments until 1 has almost the same reading as 40. then check ch 20 and it should be real low.
As I have said, if you haven't tuned your antenna as I have just explained, and have been using it as is, the possibility is high that you have already hurt the radio.
Although it could also have a bad meter. Use an external meter to read the SWR.
Other things to check. Make sure cable connections are tight. Make sure coax is not damaged. try another antenna.