I've recently acquired a 200B-1 head and cab, and on the normal channel, everything works great. The bright channel, however, doesn't work at all. The only way to get any noise is by turning the volume to max, which results in a barely audible distorted sound coming through. The bright switch on the bright channel also pops quite loudly when turned. I've opened up the head and can't see anything jarringly wrong such as bulging capacitors or anything like that. Any help on fixing this would be appreciated!