Power head brush not rotating on Electrolux epic There is suction though

Here's a YouTube video describing how to troubleshoot a electrolux 1590 power head. It will cover all possibly faults.

https://youtu.be/mQQ8HKByy3c

Connect power head directly to power without wands and see if’s working
If it’s working you have problems in wands or true hose
If power head is not working directly connected to power you have problem with reset switch or power head motor
Try to push reset switch several times
You have to test hose and wands for continuity and eliminate things by things

the link to a video below shows belt replacement as well as brush, press the helpful button
Changing the Brush Assembly on an Electrolux Epic 6500 Vacuum Cleaner

I have no idea just what reverse suction would be or how to get it from ANY vac. If you're looking at getting the blowing air from the vac instead of suction, then simply move the hose from the suction end to the exhaust end.

Does the power nozzle motor come on? Is it just that the brush won't turn? If it's just the brush not rotating, the belt probably broke and needs replaced.
Is the brush clean? If not, clean all threads, etc. off.
Check all wire connections for breaks, cracks, and discoloration. Power nozzle to wand, wand to wand, wand to hose. If any of those are found, that part, and probably the one it connects to. will need replaced.
Ensure all connections are snug.
Internal wiring, including connections, could be bad. This would include wiring in the power nozzle, wands, hose, or canister.
Reset or hose switch could be bad. These would need replaced.
Power nozzle motor could be bad. Generally the belt will break before the motor burns out, but it's possible it's didn't.
For any internal repairs, including belt replacement, the entire vacuum should be taken to an authorized Aerus Electrolux dealer. The service technician can also troubleshoot and find the problem. This is generally done at no charge.
You've got a great machine, and with proper care and maintenance it should last for years to come.

No. If the power nozzle motor is running, then a new belt will do the trick.

Actually the top comes off from the bottom base. Remove the underside screws, flip the machine over and gently remove the gray cover from the motor and brush assembly. Once inside, remove two more screws holding down the brush cover which is also part of the tunnel. It will reveal the brush, belt, and much dirt so be prepared.

This portion rarely needs replacing. It is designed to pull easily away from the brush side in case of blockage and then may need to "unscrew" use only the identical component form an AERUS Electrolux dealer. This should be accomplished without dismantling the head.
If there is evidence of glue or contact cement type adhesive on the bag side, you may need to tear apart and unravel with pliers

This is a bot of a blind guess, I don't know the model. But most power head cleaners I have worked on use the suction of the vaccuum to spin a turbo fan in the head (like blowing a child's windmill). The head not spinning is usually because there's not enough **** to spin the turbo fan. Check for:
Gummed up brush bearings (dirt or damp) making the brush harder to turn than it should be.
Poor suction caused by a blocked or partially blocked pipe.
An obstruction that is tactchin the beater or the turbo fan.
Blocked filters on the cleaner, reducing the **** and thereby not providing enough vaccuum to spin the beater.

Make sure there is nothing obstructing it from rotating. Your belt could have come off track as well. Make sure that it is attached firmly.