Lasermad.com

Connect the meter again across the points for R1 and power up. You should read about 40-50mA now. If not, check the soldering around the components connected to T1 and T2.

You can now repeat this with each pair of transistors, the reading should rise by about 50mA each time you add a pair.







Repeat for all 4 boards or for the x64 board, all 4 identical strips.

When all 4 boards have been completed and tested with a working display piece lay them out as show here:



Solder 3 scrap component legs between the bare strips running along the edge of each board to link them together. Keep them away from the holes and the outer edge of the board to avoid fouling the spacers. Now carefully turn them over and repeat on the other side. This links the 12V and 0V lines for all 4 PCBs.