Okay so I own a nikon d60 and I have an external flash that my dad gave to me. It looks pretty old. Its a Promaster powerwide FTD 5400 and ive used it on my d60 probably 100 flashes already but now I just read online that it can actually be bad for the camera and the high voltage difference can actually KILL your camera?? Does anyone know if promasters are like this or any other information? thanks!