1:Whole LED screendoesn’t work at all. Possible failure factors:Power isn’t available; Input signal is in the wrong direction;Positive and negative power supply terminals are inversely connected(IC can be damaged)
2: LED Panel don’t work but screen connection is normal. Making 4th and 5th pins of 74HC138 IC short-curcuited by soldering iron
3:There is one line not lighting among every 3 lines Possible leading factors:4953 IC damaged;
4:one line lighting but another line nearby not lighting Something wrong with A signal: Please check whether it’s not soldered well for 74HC245 or 74HC138,for which you can measure whether voltage of first pin of 74HC138 is 2.5V and just replace another IC if it’s true.
5:Lighting every two lines and not lighting every two lines Something wrong with 74HC245 and 74HC138 IC,for which solutions is to measure voltage second pins of 74HC138.
6: 4 LED lamps don’t work vertically Please check whether it’s cause by cold solder joint or replace 74HC595 IC.
No comments:
Post a Comment