Home › Evil Mad Scientist Forums › LED Matrix Kits › MeggyJR – power-on display problem › Re: MeggyJR – power-on display problem
February 26, 2013 at 4:12 am
#21205
Windell Oskay
Keymaster
Okay, column #5 – the column directly under LED D4, is really “Row 4” in the matrix, starting with row 1 on the top (your right hand side) and working down. Row 4 is at pin 23 of the LED matrix socket, and is controlled by transistor Q3, through resistor RB3, from pin 11 of the microcontroller.
So, check those points for a possible missing solder joint. See also a previous forum post on the topic: http://www2.evilmadscientist.com/forum/viewtopic.php?showtopic=5352