Odd behavior of my tlc5940 circuit and pMOSFETS

Using Arduino LEDs and Multiplexing
4

Thanks for posting the schematic, nice drawing. A few points:-

  1. As the FETs are not connected to the pins of an arduino but to some TTL you can remove the series resistor altogether and connect the gates direct to the decoder chip.
  2. On the TLC5940s I connect pin 19 to +5v and pin 27 to ground.
    I can only think you have misidentified the pins on the FETs or you are using the wrong data sheet for the parts. Some components have alternative pinouts usually denoted by letter suffixes.