On January 8, 2019, software on the Hubble Space Telescope detected a voltage level abnormality within the Wide Field Camera 3. The instrument, in turn, shut down automatically for safety concerns. As NASA reports in its feature, the issue was not the voltage level but that the telemetry circuits were giving inaccurate engineering data.

Source: NASA
A week later, NASA reported the telemetry circuits were reset and voltage levels were normal. NASA performed certain tests to verify the instrument. Wide Field Camera 3 has been functioning normally since January 17.