By blowing at the R Button, you're making it worse by introducing moisture to the contacts - it's going to improve the situation slightly for a very limited amount of time and in the long run, it will speed up the oxidation process of the button. There's a guide on how to dismantle and clean the buttons online if the button is completely dead - if it's merely unresponsive, it's probably just dust. Do your best to always use compressed air rather than blow on contacts.

If the touchscreen is malfunctioning in such a fashion, there may be a few causes - the connector ribbon might've been dislodged, a protective screen might be pressing on it too hard, the casing may be pushing down on it, it may be punctured... a lot of variables, all of which you can check by dismantling the system if simple rubbing with a microfibre cloth doesn't do the trick.

Remember, everything you do to the system is your own responsibility and you do it at your own risk - if you don't feel confident enough, send the DS in to Nintendo for repairs or look online for third-party Service Stations. Attempting any repairs without sufficient skill is done at your own peril.

This post has been edited by Foxi4, Tue, February 5th, 2013 at 10:11