Works sometimes and sometimes it doesnt.

A number of possible reasons for this---failing part in set or even bad connections on main board in the set----model listed is prone to going dead with high pitched squeel etc.

Typical PC mics need a power supply on the mic input. It's almost negligible current consumption, but it needs some DC voltage to be present. Sometimes the mic inputs are not well engineered or just faulty and this DC voltage goes away after some time.

My advice would be to obtain (borrow?) an USB headset (headphones with mic), and see if the problem occurs with them too. If not, you have a faulty mic input and will need to purchase such USB headset and enjoy.
If it does reoccur with a USB mic, then I'm as puzzled as you are... it must be a software thing, perhaps some auto-mute setting somewhere?...

The Mic is on the same board that the power button is on.. there is a problem with this board,, the problem is were the power button board plugs into the main board....... when you push down on the power button your affecting the mic''s conection to the main board,, {Its a bad plug}

The Mic is found next to the power button.. to the left look for a small pinhole,, ....try pushing down to the right side of that.. test Mic when you do this,,,

You need a new main [mother] board to fix

if you are transmitting fine Don't worry about the meter. Get an external SWR meter, they are better anyway.

Also, make sure the the switch next to the meter is all the way up on s/rf setting. thats for signal power and receive strength.

First, try another mic on the radio to be sure it's the mic and not the radio causing the problem. If it's the mic, check the wiring circuits for a bad switch or broken wire. Simply...the TX circuit is closed and the RX is open when the key is squeezed. The RX circuit is closed and the TX circuit is open when the key is released. Use a simple ohm meter to check for resistance between the pins on the mic (after removal from the radio of course). Open circuit will read 1, closed circuit should be very close to zero. You'll probably find the TX circuit never closes when the key is squeezed. Could be a broken wire or faulty switch in the handset.
Also check...If the mic "keys up"...you see the meter move normally, but no voice...it's either a faulty mic element (the little round thing you talk into) or the audio circuit of the radio has a defective component which a good CB shop can replace.

make sure your s/rf switch is in the right place on the radio is the most common problem i have found

the mics on these cobras have a receive wire in them so the transmit will still work even if the receive wire is broken,if this wire is broken the unit will not make any sound...........remove the plug from the radio end of the mic and check the connections on the 5 pin connector.....(could be a cold solder or broken wire) or try a new mic or one that is proven work on another radio
hope this helps.................good luck!

Hello Darren, Yes it sounds like the mic is wired bass ackwards,,! A cobra 25 mic wiring is
PIN #1- Shield or ground wire
PIN#2- Audio or Transmit modulation
PIN #3- Transmit or Dead Key
PIN #4- Receive Audio.
When your keying the mic, the RX wires are being connected to make the RX work,,,
*** Let me know how you get along with it. Either buy a new mic wired for your radio or you or someone comfortable with soldering needs to resolder the correct wires back on the mic plug,,,Like I said, let me know and have a great day,, Mechanic is back quiet!

put your mic on mute for playback. So the mic works but it doesnt play it from the speakers at the same time.



If you dont see microphone on the list click on
options then settings
put a X on the playback -> microphone.

close settings

its now shown in the panel, click on mute and it wont feedback the sounds to you anymore.

The Cobra 25 requires the mic to be working for any sound to come out. My suggestion is that you first try a new mic. If this doesn't work, look real close at the board on the soldered side ( around the if section, thats the area that right under the waxed area on the component side of the board ) for cold solder joints ( broken lead solder) You may need a magnifing glass. Good Luck
Ed
NC Electronic
Mills, Wyoming