Old 912 ul ignition

I have an old style silver ignition box. The ignition modules are stuffed in the box. Rotax Part number 965-320. Ignition checks are good idles and runs fine but the starting circuit is out on one of them i believe. I can start the engine with one ignition on but not the other by itself.  Has anyone had theirs rebuilt by this company.  Thanks in advance

https://www.ecurepair.com.au/product/rotax-912a-912ul-electronic-box-smd-cdi-bombardier-965-320/