K
kf4rca
Guest
The emitters and collectors are reversed on Q4 - Q7, the display drivers. The schematic is correct. This can be verified by observing that the collectors connect thru R5 (10 ohm) back to VCC. On the schematic the emitters connect to R5.
The easiest fix for this is to remove the 4 SOT 23 transistors, "flip" them, and resolder. The base connection does not change. Best to use some adhesive before resoldering.
The easiest fix for this is to remove the 4 SOT 23 transistors, "flip" them, and resolder. The base connection does not change. Best to use some adhesive before resoldering.