I bought zEQ25 4 years ago, but have used less then 10 times. Last month it begun to show 'DEC overcurrent error', so I contacted with iOptron but they said that "zEQ25 is a very old product which had out of support and no replace parts available now!"

I was so disappoint that my fresh new mount which used less then 10 times has broken, but iOptron refused to help.

So I disassembled it and decided to fix it myself.

The motor is a cheap brushed DC motor, I thought the brushes might be the source of problem, but after disassembling, the brushes seems just fine.

Next I measured the resistance of each Coils, they were 4.5R，4.3R，2.5R. It's weird that one coil has a different resistance than others. I guess the commutator might be polluted by carbon from the brushes.

After cleaning the gaps on the commutator with a knife, the resistances all rise to 6R! I reassembled the motor and do some tests, the overcurrent problem had gone!!!

P.S. you may need a 0.89mm hexagonal wrench to loose the encoder on the tail of the motor.

Customers which refused by iOptron, you now have another options: fix it yourself!