Need more info. Does the B. C. work? Is the mirror locked up? Are the curtains closed and properly aligned? Here are a few things you might try as it would be cheaper to replace than to repair.

1. Shutter curtains may be slightly misaligned. This one breaks the prime rule of fiddling inside the camera, that being 'Never Touch The Curtains'. Got an XG-1 this spring in lock up condition. After a couple of weeks waiting for the Rokkor Fairy to doink it into working order, I noticed the curtains slightly off. I pressed slightly on the outer curtain and it snapped over on spring tension. Pressed on the inner curtain and it shot over and the mirror slapped down.

2. Shutter remotely released in 'A' mode. Didn't know this would happen. Got a XG-1 this week as-is from ebay. Tested it and it functioned perfectly. But in the shutter cable socket testing I exposed in 'A' mode and the mirror locked up. Took the cable out. Locked. Moved the S/S dial through the range from 1000 to 1 and when I turned it to 'B' the mirror slapped down.

3. Faulty Timer. I would set it and trip the timer release button. The timer moved about two-thirds through the cycle and stopped. It did not have the tension to complete the cycle. Here's what you do.
a. Insert the end of a paper clip into the shutter cable lug in the center of the shutter release button.
b. While applying pressure into the lug so as to trip the shutter, work the film wind crank back and forth a couple of times.

4. Take a slender pair of needle nose pliers and VERY gently pull out the battery contact in the base of the body. Lack of tension could also be a culprit.

5. These checks could prove that you do not have a blown capacitor. Doable but a pain in the rumpus.

Enriching your Minolta experience, one piece of crap at a time.