I have a pair of old 10/100 fibre converters on either end of a fibre optic run. The collision light is on permanently on both of them and network performance over the link is abysmal. I think one of them malfunctioned because of a power surge (maintenance had to reset some trip switches this morning and the problem began) . Can I replace one of them or do I need to change both, bearing in mind the new one will probably be a gigabit converter or better? Their is no brand name on the converters. The collision light stays on even if no cables are plugged into the converter ( I presume you cannot have collisions if their are no cables plugged in).