Hi All, I'm new to the hobby so bought a Holystone F181 to try it out, based on the 5 out of 5 reviews on Amazon. Unfortunately, though all the rotors work, the darn thing would not throttle up. It just idles. Everything else seems fine. Trouble shooting suggests maybe battery not fully charged, other possible issues - all of which I checked. Contacted Holystone, and they sent another unit for free, and told me to keep the other one for parts - great customer service. But, exact same issue with the new unit. Idles but wont throttle up so wont fly. Can anyone suggest a fix for this issue?