Allen's right about the depth reading. You take the depth while you have the pinpoint button depressed.
I use the daylights out of my pinpoint button and depth reading. I'll pass my coil over a good hit many, many time before I decide whether or not to dig. Since I use Nimh rechargeables, I don't care how much battery I use. After I get a hi-coin hit, I pinpoint and trace the target from all 4 directions. Coins have a tight profile. After you pinpoint some coins, you'll know what I mean. Take some coins and some of your square nails out into the yard. Cover them with a piece of cardboard. Practice pinpointing and you'll see the difference the 2 targets make. Now, a deep piece of iron will have a fairly tight pinpoint also.
I also don't dig many targets unless they continually hit coin in all 4 directions consistently. Not many people will tell you to do that as some coins come in as iffy one way targets. while I agree that can be true, my experience is that darn few coins don't at least hit in 2 directions. Even at 2 directions, I get lots of junk. That's why I rarely dig unless it hits in 3 or 4 directions. Am I missing some coins, no doubt, but I rarely dig a rusty nail.
Keep trying. Don't let it beat you. You can do it.
Another word on headphones. My favorites are some Maxells I got on ebay used for 6 bucks. They have an inline volume control and seal around your ears. I bought a headphone extender cord at Radio Shack. I put the extender into the machine and run it to my belt. I run the lightweight headphone cord down under my shirt to my belt to where I connect it to the extender. These are the only phones I can stand to wear all day. I have 2 other sets. Koss TD-80s and some White's Royal somethingorother. I hate the White's phones and I wear the Koss's when I'm only going out for 3 hrs or less.
Good Luck