Radio sticks in TX mode after I let go of the button on the mic

Have you tried keying it without the coax attached ? Take the mic apart and give it a squirt of electrical parts cleaner .Try using a different mic also.

try your mic

Check mic wires inside connector. Try a different mic from another cobra radio.

Get a SWR-PWR meter to put on the line between the radio and antenna to see what it is doing.

CHECK SWR's, and check for loose coax connectors and try a different microphone. new stock mic's $6.99 max price here in temple, TX, and rk56 noise cancelling mics$38.99 Max here too Temple, TX.

Hi danimal, my name is John. Welcome to FixYa. Try a different mic. that fits the radio. Then if you have further problem, let me know. Thanks for choosing FixYa. Happy holidays........John

Do you have talkback installed? It my be too loud and causing feed back. Back the mic gain down if so.

Could also be improper mic wiring. If you use a mic that is wired for a different radio, it could just cause a hum, buzz or squeal.

Another thing that can cause a hum, buzz or squeal is a faulty volume and or squelch knob depending on the radio.

• Turn down or disable talk back.
• If you cannot turn off or disable talk back, lower mic gain.
• Try a different mic that you know is wired for cobra.
• Play with volume and squelch knobs while TX and see if it stops at all. If it does replace knob.
  

Take the cover off, flip it over solder side up, check all solder joints for cracks, cold solder joints, check the safety diode where it comes in the radio, before I go further, can you pick up the weather channel?...Does the PA work?...need to check the pre-driver and finals,audio chip, hook up the power meter using a coax three foot jumper from the output from radio to the input of the watt meter, then the antenna, first check the SWR, on the scale on the meter to cal/swr mode,adjust it to spec, then while still keyed down turn the dial to SWR,if it is the safe range your ok,then turn the Dial to 10 or 20 watt scale and key the mic. Does it have any wattage? If not suspect the finals, they are located on the back rail, if it does have RF then its the audio chip, its located on the right side rail facing you,closest to you.remove it and replace it with same ....hope this helps....

It is not a dirt issue, the final transmitter is bad. This is caused normaly from a bad antenna or wire going to the antenna. These can be replaced. There is one big on near the back of the radio, 3 prong black transistor connected to a piece of metal (heat sink), unsolder the old one and obtain an exact replacement. (perhaps radio shack or repair shop), solder the new one in. This will sometimes be screwed to the heatsink on the very back of the board connected to the rear of the radio.

Before reconnecting the radio have the antenna checked for damage.

Make sure you have a good ground for the radio and antenna. How long is the antenna coax if a little to long and you have extra what did you do with it coil it if so uncoil it and lay it out try it. If no luck I would shorten the coax and recheck your SWR.