Hi guys! Another trouble for me
In the second 8x4 lamp matrix, the row 11 is completely out. I've checked diagrams and analysed the signal... it runs from PIA 6821 (IC5) to pin 11 of 7406 (IC1), then it is inverted and continues its path trough resistors and diodes.
At the exit of pin 10 the signal is different if compared to the others of the matrix (f.e. pin 8 or 12 of IC1).
The others signal are pulsating low, while for row 11 is pulsating high-low. Thinking the problem was IC1, I changed it but the problem remains.
Any suggestion?
Thanks a lot!
Grazie e ciao!!!