Re: MeggyJR – power-on display problem

Home Evil Mad Scientist Forums LED Matrix Kits MeggyJR – power-on display problem Re: MeggyJR – power-on display problem

#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