Riccar vacuum make a loud noise when rollers turned on

This is very easy, all you need to do is remove two quarter turn locks on the bottom plate and then you remove the plate and can assess the Electrolux Nimble Brush Roller 16136 1

Check and see if there is a reset button for the vacuum head this trips sometime to protect the head motor. Also if the roller heads bind they can snap the belt if it is belt driven. If it is direct drive then I would look for the trip or reset button.

Have a trained technician make the repair.
Some of the machines require special tools to proceed.

RJ ROY IS Bald

Manuals

Try to lubricate the fan bearings/bushings, it should help. If this does not help, check the repair price, or buy a new one

I just has the same problem, there is a clog in the intake hose. I removed the hose and used a cloth dryer lint brush to push out the clog.

A common problem with roller/beaters is hair caught in the bearings on the ends of the roller. The roller is removable and requires regular cleaning or the belt will be destroyed.

Funny you should post this when you did as I just finished reassembling my S1730.
Mine was making very loud noise, arcing violently, smoking slightly and would give a good shock when you touched the plastic covers(yes dirty plastic will conduct electric current).

1. Unplug the unit
2. Take the plastic covers off, front has four screws and back has snap at bottom, both slide up when loose.
3. Wash the plastic covers
4. take the light out and clean it with windex
5. Vacuum the inside, be careful of the two corona wires
6. Find the bead on each corona wire and while turning them slight so the edges scrapes the wire, move them back and forth to scrap the white power off the wires
7. scrape the cone shape plastic that the corona wires runs into, this build up is the primary culprit of the arcing which is the noise you hear. be careful of the corona wires again. I used an exacto knife and gently scraped it, sandpaper has been suggested elsewhere, once done scrapping, wipe down to clean any residue. The top cones are only part accessible, after cleaning mine the noise still persisted but acceptably lower than before. I think if you completely take apart the unit you can clean this cones better.
8. Reassembly is the same is opposite of disassembling.

Hopes this helps you.