The A1 is what drives all your meters. Percent of load, current and such. The set will run with a bad A1, you just cant read the meters. I have in the past found them on ebay. Plug in the NSN and or part number.
Your other problem is in the A11. Static Exciter. Pull it out, take off the cover. Take a look see. Take good pictures of the Volt Ger card, front and back. Also the big transformer. In just the last 2 weeks, someone fixed his. The diodes were trash. There is also a after market VR that you can put in.
My big question is, why did the S9 trip? AND, why did you not have a light on the fault indicator? Because you should have had one.