Recently, I decided to finally do a flight controller upgrade on my quadcopter and replace good-old KK2 board with a shiny new Flip32 10DOF flight controller. After finally receiving a second Flip32 board (note to myself: never forget to double-check the battery polarity, even on battery monitor pins), I got everything blinking and working. Almost.
Buzzer, which I connected to the board, did not produce any sound (maybe except for a short click when connecting the battery). Comparing a Flip32 schematic with the real board, there was an infinite resistance between the microcontroller and a transistor driving the buzzer, although the schematic says it should be just 100 Ω. Few hours later, the culprit was found on the bottom side of the PCB -- instead of 100 Ω resistor there was a small SMD capacitor. After a small SMD rework, the cap was replaced with a slightly larger resistor and the buzzer now works as expected. A more detailed description of the rework with photos can be found here .
Buzzer, which I connected to the board, did not produce any sound (maybe except for a short click when connecting the battery). Comparing a Flip32 schematic with the real board, there was an infinite resistance between the microcontroller and a transistor driving the buzzer, although the schematic says it should be just 100 Ω. Few hours later, the culprit was found on the bottom side of the PCB -- instead of 100 Ω resistor there was a small SMD capacitor. After a small SMD rework, the cap was replaced with a slightly larger resistor and the buzzer now works as expected. A more detailed description of the rework with photos can be found here .
