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Repairing the humanoid robot “KHR1”

Hi, I am Nyanyan.


I have found an old humanoid robot”KHR1(Made by KONDO)“, and just now, I finished repairing that.


First the head had been lost, so I used MG90s for the head.

Second, I didn’t know the board, and I didn’t want to use that.



And there was  software for this board but I couldn’t find that, so I made a board which had an Arduino chip and a PCA9685(which has 16 PWM ports by using I2C)chip.KHR1 has 17 servos, so the MG90s is controlled by Arduino directly.Also KHR1 had  a Ni-Cd battery but it was too old to use, so I use a power unit(about 6V)for its battery.


Finishing the board I made it work, I found a servo broken.


Dismantling the servo, the FET(HAT3004 had burned.I tried to buy it, but I couldn’t find it because it is not made. Buying a new servo is not a good idea because this servo is too expensive.

Then I googled this, and I found it is often used in mini 4wd and they often change FETs.

According to these article, ‘SP8M4’ is compatible with HAT3004. So I bought SP8M4 with a mail order.

Also, chip resistance burned so I soldered a carbon resistance.

2016/ 8/20 11:39

But it still doesn’t work, then I turn the servo and found it is a little heavy to do that, so I thought the motor(RF020TH) doesn’t work, I took out the motor, connected a battery, and I found it broken.

I bought the motor by using a mail order and change motors, finally it worked.


What was broken:

First the motor was broken.

Second the FET burned.

Then the chip resistance burned.


Anyway, it can stand and bow now!

The speed of this servo is so fast, so easily it fall down not to make it move slowly.But the performance of this servo is really good.


Thank you for reading!

Published in Arduino KHR1 Servo motor Hardware Disassembly Remodeling