I have a Fujitsu mini split 1 compressor 3 heads 1 head works fine 2heads do not cheerp when pointing wireless remote directly at head. I can change the fan speed, the temp, the mode, but unit will not cherp so the change will not take. Unit will not even turn off when hitting power off button. Changed batteries and reset remote

Model numbers are useful for debugging this stuff online. Fujitsu has been making multi-head heat pumps for decades, and the controls are not identical throughout the ages.

Have you gone to the electrical panel and thrown the breaker, counted to 20, and turned it back on?