I am not a man of music, so I will start with a quote from a famous musician about the music instrument we have been working on. “It’s a sound that simply couldn’t – and can’t be beaten!”

Founded in the 1960s, this client’s instrument has changed the course of music history, defined genres and given rise to no small number of musical icons. It has become one of the world’s great luxury brands, a unique play on US and China’s growing consumer demand and an innovator in technology.

Project: Troubleshooting Conducted Immunity Issues in a Music Instrument

Timescale: Three working days

Scopes of work: A music instrument experienced EMI issues including radiated, conducted immunity, conducted emissions, etc. The equipment under test (EUT) is currently being tested in a formal EMC test house, with more results coming soon. Due to the mechanical constraints and UI design of the instrument, there are long ribbon cables and sub-optimum grounding topologies and the electronics are not shielded.  It is a challenging instrument and the issues need to be fixed as soon as possible. 

The key performance test is audio breakthrough during the immunity test. When audio breakthrough occurs, the sound can be heard from speakers and earphones.

By using simple near field loop attached to an RF amplifier, we successfully located the problematic areas, therefore were able to fix the issues. The product was later tested in the test house again, with a pass as a result.

Techniques of locating noise victims on the PCB

It was also the first time we used CDN for conducted immunity trouble shooting. See the following video demo to understand CDN test set-up.