My Aerogarden pump quit working (noticed no pump noise after a few days) so took it apart to try to repair or replace. At first i thought the pump was a sealed unit and ordered one from Amazon ($13 delivered) but looking at the old one only the 12 vac electromagnet is sealed and the impeller is attached to a simple round magnet which inserts into the electromagnet cavity and which was scaled up and stopping the pump. The rotor magnet and impeller twisted straight out with some needle nose pliars and i put the whole mess in a small cup of white vinegar for a half hour or so, brushed it clean with a stiff throwaway brush (the hollow pipe like handle of the brush worked great to clean the inside of the electromagnet cavity walls) and it then worked fine - so now i have a spare and you don’t have to wait to fix yours- really the cleanout didn’t take much more time than the replacement! Since the rotor, shaft and impeller unit are the only real moving parts and the electromagnet should last a long long time this is certainly the most common failure for the pump.
The led panel is a replacement i did for the original flourescent tubes which are expensive and short lived as well. I just put it on so will wait til i see how it performs before doing an ‘Ible on that.

Supplies

White vinegar
Small stiff brush
Small phillips and regular screwdriverS
Needle nose pliars

Step 1: Getting to the Pump

The water tank contains the pump and, on mine (see pic) at least, just lifts off the base which contains the electronics. The light arm is also removable and clears the way to remove the root tank. I had a large tomato plant growing which I wanted to save so just took the whole tank with plant to the sink and lifted off the plate which holds the plants and mounts the pump unit. On mine there were 2 snap out (up) braces running front to back across inside the tank which had to come out with the top plate and plant as the roots were entangled in these. The pump is held in by a snap in plate (the pic shows it with plate removed but it comes off by just prying the ears shown at each bottom side of the pic outwards and you can then pop out the cover plate from the sides and pull out the tab on the plate from the other top side of the pump enclosure shown. It was a little difficult to hold one bottom ear from snapping back in while you were working on the other. Pull the pump out from its slip in hose connection on the back side of the pump. On my garden the connector wire is run thru a push in channel from the pump to a screw mounted connector all of which should be removed from the pump enclosure to remove the pump. Later models of the garden have a little different connector but the pump is similar. Sorry for the sparse pics.

Step 2: Disassemble and Clean Pump

The end cap of the pump looks sealed but pries off easily with a knife blade inserted which exposes the impeller cover which also slips off easily with a little prying up. This exposes the pump rotor. I turned mine just a little each rotary direction to loosen the scale and was then able to pull it straight out with the needle nose pliars. Careful as it rides on a small shaft extending from the electromagnet. I then put the some vinegar in the impeller casing and down the rotor hole and dunked the rest in the vinegar for an half hr.

Step 3: Reassemble and Put Back Your Plants or Plant Something!

I brushed out all the scale with a stiff small brush which had a small metal pipe handle which just fit inside the electromagnet rotor hole to clean out the scale there and rinsed everything off. You may want to water your plant roots at some point.
Reassemble in reverse order. The cable at the end of the groove near the pump was tight to insert at that point but not bad. Also be sure the flow control dial is still where you need it (usually at 2)
You can test it before reassembly to the garden if you have a 12 volt AC source (NOT 120 VOLT) as some wall warts provide this. My garden had a removable channel cover on the bottom of the cover plate where the water is distributed and i took the time to clean it as well.

Step 4: Why the Scale?

I have been using an alternative fertilizer solution for the last 6 mo or so and its chemical makeup is a little different. The Aerogarden solution was more expensive but may be less prone to scale - anyone know??