The integrator gets an urgent service call from the client's AV engineer that there is...

The best immediate workaround is to patch the input directly to the output, bypassing the switcher. This allows the system to continue functioning while a more permanent solution is found. It ensures that the client experiences minimal downtime and disruption. Changing the power supply or replacing the switcher are also viable options, but they may take more time and resources. Calling the manufacturer for support can also be part of the solution process, but it doesn't provide an immediate workaround.