I have a Pentax ME Super camera and a Vivitar 283 flash, recently I put the flash on my camera and plugged it into the camera, and got nothing. The flash would charge and when I pressed the shutter button, the flash didn't fire. The only way the flash will work is if I press the button on the flash. However, if I move the cord that goes from the flash to the camera, sometimes I can get it to flash that way, repeatably sometimes as well. That makes me think it's the cord. Am I right?