Ryobi weed eater upper and lower shaft spins, but head doesn't spin, why?

If the lower drive of your Ryobi weed eater has broken off about an inch, it may be possible to repair it. However, the extent of the damage and the specific model of your weed eater can affect the repairability. Here are a few steps you can take to assess the situation:
1. Examine the broken piece: Carefully inspect the broken lower drive and determine if it can be reattached or if it requires replacement. Look for any other damaged components as well.
2. Check for replacement parts: Visit the official Ryobi website or contact their customer support to check if they offer replacement parts for your specific model. If the broken lower drive is available as a separate part, you can order it and replace the damaged one.

from your description the drive cable is broken.
Good luck

check for debris around the cutter

Just give it a try. Some different brands will interchange. I have done this with a Toro and it is still running.

That is called a quick-change shaft I believe. You need to take it apart at the connection and make sure that the two pieces on the inside of each piece of shaft are inner locking with each other. One piece of drive shaft should slip into the other.

If that doesn't do it, then you may have broke one of the pieces of shaft.

Good Luck!

Jim

May also be the clutch, in the drive section up by the motor. You will have to take it apart to inspect it

U broke the shaft that turns the head on the weedeatet probably cheaper to buy another one

Sounds like the clutch has taken a long trip south. If the clutch pads are not wore out, try some wd40 on the pad hinges.

rotate attatchment head slightly while inserting driveshaft

You need to check out this video...