Hi Chris, I've not met this soundbar, and likewise, cannot find a s/m for it. Can only suggest monitoring the volts on said C914 when you turn the unit off at power point. If it drains rather rapidly, maybe a short in PSU secondary, but if it maintains a charge for quite some time, then the primary is inert - maybe the control IC, which seems awol on sites I frequent. Don't forget the PSU start resistor/s
of yore. Maybe it has some.
Bruce