I have a sharp cb 4370 i plug to the car and it blown it is not the fuse

reverse polarity diode.open the radio and put your nose to work and sniff out the area where the power wires come into the set. There is a little black diode in that area and it s called the rev pow diode. Check it to see if you blew it.if you did then replace itand make sure the arrow on the diode is going the same way as the number on the board shows.

export radios rx without a mic. so its an issue in the radio.
will the PA function work?
and will the meter move.
will the green rx led change to red when you key?

If you have avolt meter or 12 volt test lamp, try attaching the leads to the plug that plugs into the CB. If there is no voltage or the lamp doesn't come on if you use a test lamp, you may just have a blown fuse. If you are using a cigarette light plug, there may be a fuse in the tip that connects to the center of the lighter jack. If you are getting voltage or the lamp does light, you may have a defective on/off switch. If you blow fuses when the CB is plugged in, you may have a blown polarity protection diode inside of the CB on the main PC Board. If you are not handy soldering, you'll want to leave that job to someone who is. Typically, the Polarity Protection Diode is Black and is mounded very close to where the power wires that come from the plug solder to the PC Board. I hope this helps. :-)

No RX or No Audio?

Could be blown protection diodes or if no audio a faulty capacitor close to the audio chip!
The protection diodes can blow if you were close by someone with a high power transmitter, then the diodes would blow kinda like a fuse to protect the rig, result no RX symptom!
Replacing the diodes will cure that problem, located close to the rear of the rig.

Hello there
There is a internal fuse on the inside of the unit that might need to be replaced and also check the fuse that is in the power cord ok?
best regards michel

yes the problem is a diode on the input of the rig. this is black with a silver band at one end it will need replacing as it has shorted out.

lkcnlasncsnc

Replace fuse with slo blow from Ace Hardware. Plugged unit in, clock worked. Turned unit on and immediately blew new fuse. Will fix it with a new unit.

there is a fuse in the block where the power cord plugs in. you have to disassembe the unit and remove the circuit boards to get to it as far as I can tell. the fuse is a 250volt 5amp ceramic fuse 20mm. I have the same problem and just found the blown fuse but I am still looking for the replacement fuse to buy.

jeff

The first thing to do is to check if your power wire actually has power to it. Do this with a test light or a multimeter. Given that the wire is powered, check to make sure your ground is good. Modern cars have so much plastic in them that grounds may be hard to find. The next step is to check the rig's fuse. Make sure the microphone is plugged in, too. If none of this helps, your radio needs repair or replacement.