Hello,
I'm building a Temperature Fan Control with LCD. Everything works great: the code, a small test PC-fan, LCD, PCB, ...
But today I wanted to finish my project by connecting the PCB to the 2x 160mm PC-fans. The TIP-122 delivers the necessary current for them.
The LCD starts flashing when the 2x 160mm PC-fan are ON.
On Github you can find the schematic, PCB and Arduino sketch: LINK
Someone who knows the solution?
Dylan
HI, sorry github won't let me see.
What are you using to supply power for the project?
Can you post a jpg, or pdf of your schematic, something as specific as an eagle file can cause some problems, ie not everybody has the program.
It sounds like your supply is not coping with the load, can you measure the 5V rail and see what is happening when the fans are turned ON.
Have you tried just 1 fan?
Tom...... 
I found it... I just forgot to add [SOLVED] in the topicsubject.
I added a decoupling capacitor over the power supply for the fans.
Dylan