I just tried something that I think might change where the fault might be. Maybe I'm wrong about this, but the reed relay is connecting K1 and K2 if I understand things. I decided to risk it and to just jumper k1 and k2 power it on to see if that would hijack the protection circuit (albeit in a potentially harmful way) and get rid of the blinking S-meter light problem. As it turns out, the radio behaves exactly the same way with K1 and K2 jumpered together, bypassing the relay entirely. I'm not the best at reading schematics so I'm not sure if there might be more to it than that, but at the very least this rules out the relay.

Is there something I'm missing, or does this indicate that maybe the problem is with the blanking unite itself and not with pb1445?