Will not turn on and smoke coming from external speaker jack and pa jack, i gues that is the only place to get out

Some radio's do this (specifically Uniden) for some unknown reason. Ideally you plug a speaker into the PA output and when you switch to PA mode, the CB transceiver part should turn off and only your voice should come out of the PA EXT speaker to make it act like a personal megaphone.

Are you following the user manual that came with the radio?
NB-ANL/CB/PA SWITCH: When the switch is in the NB/ANL position, the Noise Blanker (NB) and Automatic Noise Limiter (ANL) circuits are activated.
The Noise Blanker is very effective in eliminating repetitive impulse noise such as ignition interference. In the CB position, the PA function is disabled and the radio will transmit and receive on the speaker that is connected. In the PA position,
the radio acts as public address amplifier. Your voice will come out of the speaker that is plugged into the PA. SP. jack on the rear panel. The radio does not operate when you are in the PA mode.

When you plug a speaker into the ext. jack does it kill the radios internal speaker? It should until you unplug it; if not and you are following the about you may have a wiring issue with the jacks.

check for a resistor soldered across the P.A. jack and external speaker jack (solder side of the board) if you see one, remove it

turn volume and mic gain half way up, plug in an external speaker into the PA jack, flip PA switch and key up, if it doesnt squeal your audio final is blown or it could be so simple as mic wired wrong or broken wire. try another mic.

• That utilizes a 3.5mm jack. Like your headphone. Any PA or external speaker will almost surely come with this connector on it. But if your making your own, a 3.5mm jack is what you need.

• Hope this helps and thank you for using FixYa.

Regards, Tony

Could be audio chip.

• Insert external speak jack into pa port.
• Turn volume down
• Switch cb/pa switch to pa
• speak into mic

if you are getting audio from speaker ......chip is fine.

There are some different things you could be facing like:
the speaker sound being cut-out by the mic switch, but my first guess is the switch in the external spkr. jack being faulty. Here is a schematic for you.

http://xbones_antennas.tripod.com/id21.html

The black wire goes in the external speaker and the red wire goes in the PA jack.

The problem could be a range of things. Generally these radios use the same amplifier for the PA and receiver output. If the radio is receiving (usually the needle on the meter moves) then it may be bad contacts on the relay. Before pulling it apart check that the squelch setting is set to low and the RF gain is high. Check that the external speaker jack is not damaged (internally). If all seems OK visually try to connect one wire from a speaker (8 ohms) to the chasis of the radio and then use the other wire to probe different wires that are connected to the external speaker jack and on board speaker to see if you get an output there.

Open the case on your radio. Solder a 100 ohm resistor between the pa jack and ext speaker jack. You can add a switch if you like to turn it on and off. The lower the resistance, the louder the talkback.