a car MP3 modulator... let's see, SMT component density is probably about the same as in the MP3 player itself, and probably uses an SMT IC that's 2 or 3mm on a side....... it's not worth the trouble. by the time you figure out what component is bad, buy a new one (the IC probably sells for more money than the complete modulator), desolder the old one (without damaging any traces) , solder the new one in (again without damaging any traces or making any solder bridges) and put the thing together..... even paying yourself minimum wage (let's say about $10.00US per hour) it would have been cheaper to buy a new one for $10-$20.