So i've done some reading on the net regarding the purpose of diodes across a coil. If anything this journey so far has been very educational.
It seems that the voltage spike created when the coil is activated and subsequently released is opposite in polarity. The end of the coil connected to the collector of the transistor will be positive with respect to the coil's other end and unless something were done about it (ie the diode), the collector voltage could rise so far above the supply value that damage might be caused.
A bad diode across the coil would explain why a transistor would fail - definitely, however, would this explain why the transistor is failing PRIOR to even activating the coil, ie on first powering up the machine?
