I'm afraid that there's not much more I can say other than what I already have: disconnect it from the power, remove the base and carefully check all the connections to see if any of them have become loose or corroded. Carefully pull off and replace each spade connector in turn (by pulling on the connector not the the wires) and if the contact area is not shiny, clean it up with a fine emery board.
If you're lucky that might fix it, but I'm afraid that if it doesn't then my guess would be that RLA1 has failed.
It's probably fixable but there is not really much else you can do without working on it live and DO NOT do that.
If you're lucky that might fix it, but I'm afraid that if it doesn't then my guess would be that RLA1 has failed.
It's probably fixable but there is not really much else you can do without working on it live and DO NOT do that.
