I'm new to RC Helis, having played with one of those goofy Airhogs for several weeks and then playing briefly with a CX heli.

I just got the new Blade 400 and after going through the "pre-flight" check of control movement, I spooled it up on the carpet. After about 3/4 stick (with zero movement on the right stick), the heli rolled right over onto it's side instead of going up.

The rotors struck the carpet and pivoted in the blade grips, and it looks like one of the servos got the gears stripped off a few teeth. I zeroed the collective immediately and thought it didn't do any damage, but I can see why so many people have to replace servos now...

I've done lots of reading, and see this is going to happen a lot in the beginning... but I'll have to figure out why it rolled instead of went up like it should. But first I need to replace the servo or the gears. I'm no stranger to gears (mechanical and electrical engineering background), so I took the servo apart. It's only one gear with a few missing teeth, but it's obviously causing the servo to malfunction.

I'm going to head to my LHS today, but I called and they're pretty swamped and couldn't come to the phone. I was hoping to gather up a little information before I went. The book calls out a DS75H servo. The guy at the LHS wasn't familiar with it, but said he had a DS75 (no H) servo. He also said they have other servos (Hitech, Futuba) that would probably work. Since they're about an hour away (closest good RC store), I want to make sure I've got some part numbers and/or understand what I need to replace the servo.

Can I assume in most cases that the servo itself doesn't get burned up, so much as the gears get ripped apart? It would be super easy to just replace all the gears if they have those for sale... But if they don't, and all they sell are servos, what's the difference between the DS75 and the DS75H servos? And is anyone aware of a replacement of the DS75H that uses the exact same measurements. As it was, the DS75H was a tight fit in its mounting position. If it's not exactly the same, a replacement wouldn't fit.

And lastly, how does one go about re-setting the position of the linkage to the heli? I'm hoping it's a simple matter of plugging it in, screwing the linkage bar back on, and the resolver/encoder built into the servo will read the current position and set itself accordingly to the transmitter's stick position?

EDIT: I realize after thinking about it, that my assumption is wrong. Since the linkage arm coming off the servo isn't keyed (that I know of), how do I know what position to screw the arm back onto the new servo?