A while ago, after some forum debate, and thinking, I opted for one, then another YN568EXii.
First... hey, good design. I like 99 percent of what they have there. The build quality is pretty decent (with noted exception below). Both flashes run consistantly with regard to exposure and recycle times. They work marvelously with the YN622 remote setup. Zero issues there.
Here's whats going on with these otherwise excellent flashes. After speaking with some other Yongnuo users, It seems the first of the 568EX's had a problem with the tension on the batteries. They sat low in the compartment, had some issues getting good tension and good contact. Someplace along the line, Yongnuo listened, and put taller/stiffer battery contacts in the flash. Thats good! Problem is, they didn't beef up the door to handle the stronger force now put upon it.
Both of my battery doors broke, in exactly the same way, after the same amount of time - and they have only been used so far in the house for testing of the setup. Zero harsh treatment. You can see by the direction the little plastic lock broke off that the force was from the inside, pushing out. Both flashes broke the bottom two rear most locking pieces. Contacting Yongnuo... they said to contact their eBay store, and they'd list the door as part - about $20 each shipped from China.
That prompted me to go for a better solution, since any replacement door would have the same issue. One possible solution, too late for me, is preventative action. If you look at how the locking tab works, and fits, you can see there is room for a fillet of material behind it to give it strength. If I was doing this on a new flash... I'd use some of that great black superglue (StewMac.com). I've used that stuff to actually rebuild bakelite pickup rings on a Guild electric guitar (not standard rings, and long long out of production). Also used it to totally rebuild the lost tip of a Gibson L6-S pickguard (the forward tip, that always breaks). Its good stuff, strong, and easy to work with. Just have to be super patient and go in thin layers, allowing dry time of at least half a day each layer. Think in terms of five or six nights with a toothpick, and an out of action flash during that time.
Ok... thats not for everyone. So, let it break, then fix it.
The YN568 is easy to get apart. Very orderly inside too. Most of all, its easy to get back together! Electrical connections are snap in plugs. You needn't get it far apart though, in order to change the door. Two screws, left and right, on the main housing accessable when the flash is rotated 90 degrees. Four screws holding the shoe/base on. Thats it. It seperates.... you'll need to take the front off, then finagle the pin holding the door out, and finagle the new door into place and slide the pin in. You'll also have to get the spring arm correctly placed in the case. Not hard, just... may take three attempts before you get it right.
However, since I don't have a replacement door, and its just as bad as the original....my option was to be a little more permanent. Remember, the flash is already broken... so how bad can it be right? I evaluated the location spot for an external thumb screw on the door, judging where the hole would appear inside the flash. There's a LOT of open real estate area in that flash btw, and an external power pack would be easy to adapt in. Anyway, about 1/4 inch down from the tip of the arrow on the door, you can make a little hole and fit a nut within the flash (epoxy) and voila....thumbscrew to the rescue. You'll need a 6-32 thread thumbscrew with about a 3/8 inch long thread. Computer case thumbscrews "may" work, as I had one that fit that very description, but I also noticed I had others that were short threaded.
Now for the mod.... I may do this after Biketoberfest. Not before, in case I screw it up. I think I'll be able to fit a power jack under the door, with corresponding opening right through the door for the plug. I plan on using a standard barrel type power connection, and while not the sturdiest, a little velcro to hold the cable from moving about will be good enough - for my use at least. Power to be had from a 6v sealed lead/acid battery, as is available from many sources, and which also fits nicely in a common rifle magazine pouch. Charge with a wall wart fitted with another power jack on its cable. Quick and simple, not high tech at all. The power connection within the YN 568 is the top most and bottom most inner batter connections. The rest just bridge to each other to series fit the batteries. Don't use both power supplies at the same time please, or.... as I may do, is just remove the thumbscrew at that point, and install a flush fit screw. At that point, I'll stick a fork in it, and call it done.
Folks.... this is a good flash, many parts are hot glued in place to prevent them vibrating loose, a nice touch to see a capacitor not just hanging in the air, nice to see the little connector cables all with plugs and jacks inside the flash. This is not a junk item, by any stretch of it whatsoever.
Hope some of you may be of benefit of my misfortune, and my couple of fixes.
PS - I went out today and bought some things to actually do the fix. Ended up getting some 8-32 nylon thumbscrews from "that big box home store" for the whopping price of $0.75 American money, and since my 8-32 tap was worn from tapping some stainless steel motorcycle parts... I opted for a new tap and the proper drill as a kit for about $5.25 in similar American money. Total price with tax, just over six quid.
I ended up using a small chuck hand held, and things drilled and tapped nicely. Had to go back and enlarge the hole in the door a little, to allow the thumbscrew to easily pass, and alls well - save for a little deburring to get the excess from the edges of the holes. In nylon, the slightly larger 8-32 size made more sense for strength, and there's just enough meat in the plastic of the body to allow direct threading into the material. Nylon on styrene should be ok. Should it wear, I can always fit the epoxy'd on screw as formerly described.
Pictures in the next post, no particular order