TLC5940 not working at all

Other Hardware LEDs and Multiplexing
1

Hi again,

can you help troubleshoot my problem with brand new TLC5940NT I just got?

I wired the chip correctly per instructions in BasicUse example from latest library (Arduino Playground - TLC5940), uploaded the sketch but there is no sign of activity on LEDs. I reduced LEDs to a single LED, triple checked all connections, replaced Deumilanove with Mega2560 (respecting pin assignment change), separately verified PWM functionality on used PWM pins, tried to reduce resistor from Iref to Gnd, nothing... Not even a flash pulse.

Are there other things to check before ordering new chip?

Thanks

qwertysimo

2

Make a picture of what you built, or draw a schematic, nobody can guess what is on your breadboard by just reading 'I hooked it up like here' because 9 out of 10 times something is wrong.

Did you put the LED's the right way around? Remember, the TLC5940 is a current sinking LED driver!

Have you got a multimeter? If so, measure the outputs of the TLC that you activated, see what comes out.
If you don't have one, get one! Even a cheap one can be great to debug a simple circuit.