Just got my new Rebel and went to see if my old Speedlite 199a would work with it but it won't power up (the Speedlite that is). It's sat in my AE-1 bag for quite some time and at a quick glance, noticed mild corrosion on the battery terminals. Is this unit worth fixing (and if so, anyone know where I could find a repair manual on it?) or should I just look for another flash? Thanks!