Vintage 1979 Budweiser Clydesdale Lighted Sign Digital Clock 004-130-79 READ For Sale

Vintage 1979 Budweiser Clydesdale Lighted Sign Digital Clock 004-130-79 The digital clock will light up. I think the clock needs to be reset. However I’m not sure how to do that. I can get the digits to light up, however when I release the time adjustment buttons, they disappear from display. I’m not 100% sure the clock works like it should.