[Blackheart]

I've been keeping and using Aquaclear filters for quite some time now and they do a great job. I've been using the 70 model for my 55 ever since I first set it up.

I did however do a water change the other way, and some filter maintenance and went to turn the filter back on, and it was just dead. No sound, no movement, nothing. What's up with that? Though they are great filters, it begs me to ask the question; are they cheaply made? Has anyone had similar problems?

 

[Mango]

You gotta push the impeller a bit and it will start moving.

 

[PlantedRich]

For long term, we might ask how you clean the impeller section. If you don't take filter off the tank, take the motor off the filter and really do a cleaning on the impeller itself, debris and algae (gunk?) will build up and keep it from restarting. A push will get it starts until it get heavier but then I don't want to be there to restart it every time the power blinks so I favor cleaning it better. It can also save you needing to replace the filter if you really clean anything like sand that gets down into the impeller. A bit of sand riding around in there can score it bad enough to require replacement.

But then also be sure something is not wrong like the power to the outlet off or something really simple.

 

[discuspaul]

For long term, we might ask how you clean the impeller section. If you don't take filter off the tank, take the motor off the filter and really do a cleaning on the impeller itself, debris and algae (gunk?) will build up and keep it from restarting. A push will get it starts until it get heavier but then I don't want to be there to restart it every time the power blinks so I favor cleaning it better. It can also save you needing to replace the filter if you really clean anything like sand that gets down into the impeller. A bit of sand riding around in there can score it bad enough to require replacement.

But then also be sure something is not wrong like the power to the outlet off or something really simple.

This response is right on the mark.
We don't know how long your tank has been set up - so we also don't know how long it's been since your AC 70 had any proper maintenance of all of it's parts.
As Planted Rich said, the motor housing itself & it's impeller shaft needs regular maintenance (on any AC HOB) as the rest of the unit does.
As was said, you need to remove the motor unit from the filter box, open it up & clean all the insides of accumulated gunk, including the impeller shaft.
You can do this by inserting some tissue/paper towelling wrapped around a toothpick or something similar & pulling out the gunk that gets caught up in it.
Once you've done that, I'm sure you'll find the filter starts back up like a charm.

 

[WaterLife]

Yep, as the others have said, unplug it, pull out the impeller and give everything a scrub.