I can recieve other people, but when i transmit the tx light comes on, ican hear a bit of hash but no voice comes out

You check your radio with other radio very near. If radio is hearing your transmission then it mean that your Radio Power Module not working if very near radio not listening you then your preamplifier and Power amplifier is not working, it mean your Radio Transmitter faulty, only Receiver is working, you consult with any Radio Service shop. One other thing if you have software also check Tx/Rx frequency it must be same for simplex operation.

its very easy to blow the transmit transistor circuit if shorted

https://www.cobra.com/sites/default/files/manuals/29LTDCLA.pdf

can you hear it though, sometimes these lights stop working

I would open up the radio and look for burnt traces, primarily by the output transistor and near where the power comes in. If you have another radio near by (within several feet) and it transmits on the same channel that your radio is on, can you hear it?? If you transmit on your radio, does the working one hear you? If you open your squelch, does it make noise?? If you transmit, does the RF power meter go up?? If any of these questions are YES, then there is a good possibility that your ANTENNA SWITCHING diodes are shorted or open. The TX diode is probably open and your RX diode is shorted. OR both. If the other radio is hearing you, and you are hearing the other radio, then the radio section is very likely OK. The diodes switching the antenna between RX and TX often fail, especially if there has been a lightning strike in the vicinity. It doesn't matter if your radio is on or not, or if you have a surge protector, a nearby lighting strike can take these diodes out.

If you don't have as much as a Channel number coming up on your radio, then the problem is most lkely somewhere in the radios internal power supply.

REPLACE THE FINALS,does it come on?

The first light, I assume is on constantly, is power/connection, and the two that blink will be Rx and Tx, Rx = recieving data sream, Tx = sending data stream, even if you think that nothing is being transmitted, "static" is sent/recieved to maintain your connection.

Hello lummox30,

Check you mic first to see if it is indeed working. Then if it is the below advice is applicable.
It sounds as if your TX audio amplifiers might be malfunctioning or the TCXO might be bad. If you have a background in Electronics I would suggest that you open up the unit and using a dummy load on the antenna check the two TX audio amps to see if when you key the mic and speak into it the amplifiers are amplifying your voice and sending it to the modulator. If the problem is not amps or the filters in between the amps, the modulator and the VCO buffer are suspect. If the TCXO is being modulated I would check the PPL IC and the Drive amp to see if the modulated signal is getting through. The last two checks I would perform are on the final amp and the TX switch prior to the antenna jack.

If you do not have a background in electronics, still check your mic, but the rest of the above advice can be done by a qualified Radio Technician.

I hope this helps,

Thank you,

Shuttle83

Is the squelch off? Is there even a crackle from the speaker? Does it appear to go into transmit?
If you have a friend can listen in while you try transmitting, get him to let you know if voice can be heard, or a carrier appears (on AM). If TX OK, try sideband, if OK, look for faulty speaker/ socket/ wiring. If no audio on TX, suspect the audio amp is bad.

Check the squelch on your radio thats not recieving. If there is a monitor button ( when pushed you will hear static) try pushing it.. then get someone to call you so you can check if you can hear them. On these radios you have 2 types of squelch....1 is called carrier squelch.... it basically opens when there is a strong enough signal. This lets you only hear strong signals and "squelch out" the distant ones and background static. The2nd. is "tone squelch" ... with your radio they are often called privacy tones. If you have 2 radios set with the same privacy tones you will only be able to hear each other... only radios that are transmitting with that privacy tone will be heard on your radio. Its a high frequency tone that can't be hear by the human ear that gets "embeded" with the transmitting signal. The recieving radio hears it and opens the squelch. So... if the radio thats rxing (recieving)your signal has its squelch set for just carrier squelch it will hear any signal thats strong enough to break the squech open.... basicaly any radio within a certain range. But if your radio (one with problem) has its squelch set for privacy tones you will not hear any other radios except the ones set with the same privacy tone.... the squelch will not open until it gets a tx signal with the right tone.... so if the txing (transmitting) radio is not using tone squelch but is using carrier squelch.... and the rxing radio is set for tone squelch... the rxing radio will not hear it. With tone (privacy tones/codes) squelch you need a tone to open the squelch and then the audio can be heard... with carrier squelch the squelch will open if ANY radio is within a certain range. Check the squelch setting on the problem radio... it could have a privacy tone set. Try pushing in the monitor button so you can hear static ( you want to hear everything including static) on both radios... tx on one radio at a time and listen if it can be heard on the other with the monitor button pushed. If you can't hear any audio when the broken one is transmitting then it COULD be the mic.... if you can hear both radios with the monitor button activated than the radios are txing and have tx audio and are working... if thats the case its the privacy tones that are the problem. Take care

Model #? Name?
black box? make sure the tx rx are reverced on both ends.