Gentlemen, I discovered my error. I didn't mention in my original posting that I was using the camera in my studio with a PC sync cord to my lights. I apparently left the Flash Synchronizer Selector on the Yashica on the "M" setting instead of the "X" setting. The "X" setting is for electronic flashes.(posted 8217 days ago)I made the switch on a roll this morning and all is well! Thanks for your help.