Right fan speed sensor disconnects

Hello everyone, I got a MBP A1990 for video editing and live music mix, but sometime ago I noticed that the fans start at max speed when I boot up my laptop, after 5 or 8 minutes everything went normal again, however, about a month ago it never went back to normal and the fans kept at max speed. Installed an app to see it can control the speed fan (like with the old iMacs when the HDD got replaced with an SSD), but it didn't worked, however, I noticed that it's the right fan the one with a problem, and every time it goes at max speed, the speed on the app shows 0. Could it be a speed sensor related issue? Can be solved by replacing the fan or need to change the whole logic board? Any help would be appreciated :)