Doser 2.1 Malfunction

Hello,
In addition to my running dosers, I have an additional Doser 2.1 from my local friend.
It was stored for a while, I recently set it up for trace elements dosing.
The phenomena are as follows.
1. The unit shows amber and red logo LED flashing alternatively.
2. The firmware is up-to-date.
3. All the normal indicaters are on on the unit and GCC shows the local time correctly when the unit is connected thru USB (stand-alone).
4. Changed settings on GCC are stored in the unit correctly.
5. The manual dosing buttions on the unit are not working.
6. The manual dosing of both "specific amount" and 'dose while press" on the GCC do not work.
7. A new spare pump motor is replaced with that of Pump #1, but it is not working. (Seems like pump drive circuit is fail.)
8. No error message appears on GCC.
9. what he touched the Doser recently, he applied a little silicon grease on the rollers and tubles.

Your kind help would be appreciated.
Thanks in advance.
Son in Seoul Korea.