My grinder spins but no coffee powder coming out. I tried to open the top cap to vacuum out the beans and cleaned it with a brush and so, but still no coffee powder coming out from the grinder. What can i do?

Your question is not right.
Grinder stops on its own in 16 to 18 seconds (times out).
It may not be grinding beans an spinning free because the beans are not feeding.
You may have used oily beans or set the grind fineness at very fine powder like. This powder like fineness also clogs the grinder..
You need to clean the grinding chamber and the ground coffee outlet.

Btw, I’m available to help over the phone in case u need at https://www.6ya.com/expert/edward_bbd2c7ff4ee1828a

It is most likely that something is blocking the pathway to the grinder. As the Rocky is a direct drive grinder there is no gear that could be broken.
Try to remove the beans from the hopper and inspect the pathway, move the beans that might be under the 'disk'. If that is not working you might have to open the grinder;

• remove all coffee beans
• unscrew the three screws in the bottom of the hopper
• remove the hopper

Now you can see the grinder wheel and tell if it is turning normally.
This might be a good opportunity to give the grinder a thorough cleaning.
Do not soak it in water, just a stiff small brush (e.g. a toothbrush) is the best tool. And perhaps accompanied by a vacuum cleaner :)
If you have been using very 'oily' beans for a long time they might have clogged the grinding wheels.

Good luck,
Villi

When the grinder spins free and fast it only means that fresh beans are not feeding into the burrs. This happens when:
1- Grind setting is too fine and beans cannot enter the grinder mechanism.
2- Use of oily dark roast beans can clog the ground coffee chamber and preven the fresh beans entering the grinder.
3- The ground coffee chamber outlet is clogged due to oily beans or too fine coffee setting.

When you cleaned the grinder you may not have cleaned the coffee outlet to the doser on the left. You can clean the outlet to open the passage of coffee grounds to collect in the dosing device..
After cleaning the outlet, you should next make sure that coffee grounds are not packed in the doser. The doser is inside the door right above the brew group.
To access the doser:
1- Remove water tank.
2- Remove the brew group.
3- Lay the machine on its back for full view of the doser.
4- Pull the doser door open (it is like an Attic door.
5- Keep the doser door open and clean the inside with a brush. The outlet from the grinder is on the right side with a wire wiper cleaner that moves across the grinder outlet fills from the grinder. This opening.
Use a brush to clean the doser.
On the left of the doser space there is a plastic flap that is pushed to the left when coffee grounds fill the doser.
At certain distance push back (1/4") the notch on top of the flap pushes the doser micro switch pin to stop the grinder. Push the flap gently to the left to make sure that it is moving well. With each push back of the flap, one can hear the feeble click sound from the micro switch.
When the above cleaning is done, try the grinding.
If the conical burrs have not been replaced for over 2500 grinds, it is time to do so.

The above grinder and grinder doser cleaning instructions are available as download files on the following page link:

One can find many useful maintenance guides on one page.
Good luck.
http://www.partsguru.com/MaintenanceofEspressomachines.htm

Btw, I’m available to help over the phone in case u need at https://www.6ya.com/expert/edward_bbd2c7ff4ee1828a

- coffee-channel is stuck.

check google for calibrating/cleaning your gaggia.

This can be caused by several things;
If it used to be good but is now faulty it is most likely that it just needs cleaning. If you are using beans that are 'oily' they can clog the grinder, you should anyway disassemble it and clean every year. Do not use soap and water, just brush it with a stiff brush (e.g. the stiffest type of toothbrush) and a vacuum cleaner.
There is also a possibility that something has got into the grinder along with the coffee beans that has damaged the grinding wheels; in that case you need to replace the wheels.

Unplug first. Unscrew the top. You need a long thin screw driver Phillips head is the best. Pock around the exit and entrance where the coffee beans are ground. Remember, the better the coffee and you will get more clumping of the beans. I works great. It is pain. The Chicago Clout man exits.

This fixes almost all the "beans will not feed or beans will not grind" problems caused by coffee bean dust packed in the burrs. Oily beans cause this problem more fequently.
a. Pour all the beans out the top.
b. Open the settings up all the way and see what else can be poured out. Use your shop vacuum to **** grounds out the spout and backward out the bean bin.
c. Pour in some instant rice and start grinding. Reduce the grind to a small setting like six and then open the settings all the way again. (The grinder will not start at a low setting with the rice in it. If you let it stop, open the settings to about 16 before trying to restart.)
d. Pour out the rice and vacuum out the ground rice.
e. Adjust the grinder to your favorite setting and try a coffee grind. Grind until most of the rice dust is expelled (any remaining trace of rice dust will not affect the flavor of the coffee).

This fixes almost all the "beans will not feed or beans will not grind" problems caused by coffee bean dust packed in the burrs. Oily beans cause this problem more fequently.
a. Pour all the beans out the top.
b. Open the settings up all the way and see what else can be poured out. Use your shop vacuum to **** grounds out the spout and backward out the bean bin.
c. Pour in some instant rice and start grinding. Reduce the grind to a small setting like six and then open the settings all the way again. (The grinder will not start at a low setting with the rice in it. If you let it stop, open the settings to about 16 before trying to restart.)
d. Pour out the rice and vacuum out the ground rice.
e. Adjust the grinder to your favorite setting and try a coffee grind. Grind until most of the rice dust is expelled (any remaining trace of rice dust will not affect the flavor of the coffee).

You need to open the grinder, it`s probably packed with old fine powdered coffee that blocks the outlet. Clean this out and try again. Since it works normal when you use pre-ground coffee, there shouldn`t be any problems with any other parts.

Let me know if you want a description for have to open and clean the grinder.

Good luck!

This fixes almost all the "beans will not feed or beans will not grind" problems caused by coffee bean dust packed in the burrs. Oily beans cause this problem more fequently.
a. Pour all the beans out the top.
b. Open the settings up all the way and see what else can be poured out. Use your shop vacuum to **** grounds out the spout and backward out the bean bin.
c. Pour in some instant rice and start grinding. Reduce the grind to a small setting like six and then open the settings all the way again. (The grinder will not start at a low setting with the rice in it. If you let it stop, open the settings to about 16 before trying to restart.)
d. Pour out the rice and vacuum out the ground rice.
e. Adjust the grinder to your favorite setting and try a coffee grind. Grind until most of the rice dust is expelled (any remaining trace of rice dust will not affect the flavor of the coffee).