i currently working on a lecture task in laboratory, especially aquaculture and meet this problem
my air pump doesn't work anymore
because i'm not sure it's about the power wire problem (the power wore looks good in condition)
so i decided to disassemble it and check for the internal components problem,
hope this instructable solve your problem
and sorry for bad english
(btw this is my first instructables hope you enjoy it)
Step 1: Disassembly
make sure the power line is-OFF-the-power-socket
turn your air pump upside down and unscrew it
don't lose all the bottom screws, you'll need it later
so keep it,
turn your air pump back, and open up the lid/cover
Step 2: Core of the problem
just leave that last two part intact
the inner component, the adjustable part is torn by rust...
i decided to disconnect the power wire from the pcb to magnetic coil, and the main power source... i use scissors to cut the wire (oops)
i want to connect it directly form main power source to the magnetic coil.
i broke the pcb and put them away, and it's look poorly damage. But i leave the moveable knob stay in its place for an aestethic reason, unless you want to throw it away and you'll got a hole in your air pump.
Step 3: Connect the wire
i just using pigtails knot to connect it... you can using tape to secure it
but me, i just leave the pigtails
Step 4: Here come the shock!
PROCEED WITH CAUTIONS
connect to power socket...
voila... it's vibrating
if it's not vibrating, this instructable maybe not for you...
Step 5: Re-assembly
assembly everything except the pcb... and don't forget the screw...