As this radio shack trc 503 cb radio will only transmit but it has loss it audio sound and no noise as nobody seems to don't why this has loss it audio and soun

SOURCE: Radio Shack TRC-502 cb radio

Here is the owners manual I'l see if I can get my hands on a internal schematic

http://support.radioshack.com/support_electronics/doc62/62220.pdf

SOURCE: I need schematics for my radio shack trc-503 cb radio

Found what you need:

This comes in two parts -

first, this link:

http://www.eserviceinfo.com/download.php?fileid=34491

second, this link:

http://www.eserviceinfo.com/download.php?fileid=34492

save both to your desktop and execute part 1. It will create an Adobe PDF file. So make sure you have the Adobe PDF Reader installed - http://www.adobe.com/products/acrobat/readstep2.html

SOURCE: radio shack trc-502 cb radio

YOU CAN GET SCHEMATICS FOR THAT MODEL
I JUST LOOKED IT UP FOR YOU........THE BOOK IS SAMS PHOTO FACT...WEBSITE IS

WWW.SAMSWEBSITE.COM

THEY HAVE EVERY CB RADIO EVERY MADE

GOOD LUCK