Teensy 3.1 OctoWS2811 atrifacts only on led2 line

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RichardFerraro

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I have followed all of the posts on flicker.

I have two independent systems with different Teensy 3.1, 74HCT245 drivers, power supplies and different strips of 2812b's (one 36 long and one 90 long).

I have been very careful with short wire lengths and 20 AWG wire with each strip tied back to power.
I bring both signal and ground from each strip back to the 74HCT245.

I have tried different resister values (no resister seems to work best).

On both systems:
I get unintended pixels turning on (or not turning off) on the led2 line (pin 14) of the Teensy 3.1 through the 74HCT245.

As I have cleaned the system, I mostly get no pixels in error, sometimes one or two.
The problem is always when low brightness values are used.
This is especially true when I am setting the value for only one pixel and issuing a show().

On either system, I can swap Teensy LED pins (e.g., swap LED2 and LED4) and the problem always follows what ever string of led's are connected to LED2 (pin 14).

I NEVER get bad pixels on any other string.

I conclude that something is up inside the Teensy 3.1.

Any suggestions anyone?
Is anyone else testing by just turning on a single pixel?
 
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