This upgrade is for robots equipped with controller bottom board ver. 2.3 rev. A-C. It is an improvement of the eye servos current measurement unit.
For this operation you will need three tools: a soldering station and tweezers.
To perform this hardware upgrade, you have to get following parts:
1. The first step is to remove EMYS controller from the head.
2. Take out the bottom board of the controller.
3. Each servo has an independent current measurement circuit based on ZXCT1109 integrated circuit. See full controller schematic here LINK.
4. Replace four (3 resistors and 1 capacitor) elements for each current measurement circuit on the EMYS controller bottom board.