What usually happens with the neg carriers is the hinge pins break - These are (I think) made of plastic, but are easily replaced. I have two of them, both sets had broken hinges. Drilled out the remains of the pins and replaced them with M3x0.5 set screws.
Originally Posted by aca91
I have a spare TR450 power supply, but shipping to anywhere is going to be very expensive - It is possible to use another 24V 250W power supply, but it is not a straight forward drop-in replacement. I have a circuit diagram for the PSU which I can send over. It will give you some idea of what is involved.