Scroll

i have a Rapoo VT3 Pro, after a year of use, it started having problems with the scrollwheel, when i scroll down, it either goes up or doesn't go down, and it's constantly intermittent. Every time i blow on the scrollwheel, it temporarily returns to its normal position, but then the problem returns. I've already opened it up and used a hairdryer (on cold) in various directions, but it didn't solve the problem. Is it still possible to fix it, or do i have to replace the incoder?