Green LED for Line input

Dear All,
I am using the Line input into the Pro V3 board. To do this, I am using the four pins PH2 connector situated on the board, and not the 3,5 mm mini-jack on the back of the board. This works fine, but the problem is that the green LED does not stop blinking. It only stops blinking when a mini-jack is inserted into the back of the board.
Does anyone know if there is a way to have the green LED continuously on and not blinking, without having to insert a mini-jack at the back?
Thanks for your help,

Hi @Frank222d,

Try to short the switch pins of the jack socket!

A schematic of the board might shed some light on why, but alas none are supplied.
Is there some reason why you cannot use the jack socket?

Hi @zitev
Not a bad idea; but I need to figure out which are the switch pins and which are the signal pins. In addition, I am not sure wether the switch pins are normaly open or normaly closed.
I was looking for a solution linked to the software, e.g. with an api.

Yes a schematic would be helpful. I cannot use the jack socket because I have another board which is situated just behind the ProV3 board. In addition, I find the quality of the contact within a mini-jack socket is not so good, I’d rather use the 4 pins Ph2mm plug on top of the ProV3,


it’s very simple, check the legs with a multimeter, also with the jack plugged into the socket and pulled out.

Dear Zitev,
Thanks for your recommendation. Your proposal is exactly what Coco from Arylic also recommended us to do! Here is a picture of the pins that have to be connected in order for the green led to stop blinking:
Best regards,



I’m glad I could help, thank you for the photo feedback on behalf of everyone!