sohc_coupe24

I bought a boost guage a while back when I had a mild turbo set up going. However, i decided to stay stock and sold all of my f/i parts. Now the only thing i have left is the boost guage. Recently though, i let my friend use my boost guage for the time being and for some odd reason when he gave it back, the needle was stuck at 15 psi. Question is, do you guys think its broken? I have never used it prior to buying it. I bought it brand new from a reputable shop.