Do you have pleated day/night shades? If so, you have a string or two strings coming down one side of the blind and secured to the wall with a little round plastic holder. If you loosen the screw, you can either release some of the tension by pulling upwards on the strings or increase the tension by pulling down on the strings (below the holder). These type of shades have a spring at the top of the shade and the cords are attached to each end of the spring and then have a certain alignment through parts of the shade and exit at the bottom rail. If you end up having to restring the blinds, it's not that hard. Send me a PM or respond on the thread and I should be able to send you a couple of links that provide excellent directions on how to do it.
Retired but busier than ever!
2012 Newmar Bay Star 3302
5 Star Tune, SumoSprings, Roadmaster Steering Stabilizer, Blue Ox Avail
Brake Buddy, 2015 Chevy Malibu