screw (countersunk for the master panel design) into the hole from the front, and fit a washer,
star washer and nut onto the screw but keep it loose. Do the same for the TIP145.
Now if you have done all this correctly, you should find that the when the power supply PCB
is aligned once more, you can coax the power devices’ legs through the respective pads on the
board. You will probably have to wiggle the power devices about a bit to get it to fit
smoothly. Check that the transistors' leads have not been pushed downwards at all – they
should not be touching the metal panel.
Place a star washer on a 6mm screw and a plain washer over that. Place into one of the PCB's
mounting holes and screw into the hex spacer but do not tighten. Do this for the other three
holes. Now secure the transistors in place by tightening the nuts. Do not overtighten. All you
need to make sure is that the transistor sits firmly to the panel. If you tighten it too much the
device will lift at one end and not sit flat against the insulating pad.
Then gently tighten the board's four screws. Again, all you need to do is secure the board.
You can now solder the transistor leads from the top side of the board. Any excess lead
lengths can be cut down as you would a normal component.
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