Yeah, if it's that bright, check for a defective/non connected/reverse/totally absent diode along that particular row/column. Had something similar, albeit much worse on one of my pins before. A whole column and one row was always on when just one lamp lit up. Someone 'replaced' a lamp holder, but there was no third prong for properly connecting a diode, so he probably figured that it wouldn't hurt running it without one. Became really obvious when I filled the complete matrix out with LEDs.
(Topic ID: 156856)
Sioux Falls, SD
