Take a look inside your tomtom go . The photo's uploaded are of the GO and Go 300 / 500 / 700 series so yours might not look exactly the same but will be similar to these. SEE PHOTO of the IC's highlighted RED. U24 is on the same side of the circuit board as the card reader. U25 is on the same side of the board as the power socket. These are the 2 chips / IC's that will be blown if reversed supply or more than about 6 volts has been applied. The blown components are usually blown due to attaching the WRONG charger or a faulty charger. ( the tomtom cigarette lighter leads often go faulty ) These IC's are very very small ( just 3.5mm across ) and the 10 pins ( 5 on each side ) are even smaller and very close together therefore normal soldering ability will not allow a novice to replace them. Special soldering irons are needed , magnifying glass or special microscope for electronics + a steady hand and good light. Its highly unlikely that a home repair is possible. Besides that , even engineers with years of soldering experience have great difficulty replacing these components and it often takes me 30 minutes just to replace one of these IC's and I have a steady hand. Most normal electronics repair companys cannot repair this type of component as they will normally deal with bigger things. So unfortunatly, your "corner of the street" TV repair shop won't be able to fix it for ya either. As far as I know TomTom don't repair these IC's either as its too fiddly and time consuming and for them not worth the effort. Your only hope is one of the repair people offering this service on online . Try a look on ebay under "faulty tomtom" .