Can't turn on all LEDs in row using 7219

Other Hardware LEDs and Multiplexing
1

I have a large 5x7 LED array connected and am using the LedControl library. I can turn on every LED in a given column, but only four in a given row at a time. Turning on more than four causes the LEDs to briefly light up (just a flicker) and then all go off again. All LEDs can be turned on/off, so the LED matrix appears to be functional.

This sounds like a current issue, so I turned down the intensity (software control) to 1/2 of the value but the same exact thing happens.

My current limiting resistor is 10k. Am I exceeding some maximum for the chip? I would have expected the LEDs to dim, not flicker on and then turn off.

Any ideas?

2

Found my own problem. The current limiting resistor needed to be larger. Increased it until the problem went away, then increased a tad more for good measure.