HELP! My keyboard doesnt want to function properly!

[bkgrnd]

i just soldered the rows and columns of my keyboard to the pins of my microcontroller but for some reason only 3 out of 12 columns work
when i check everything with a multimeter there are NO shorts, everything works as intended but when i solder everything to the controller i get that problem.
ive tried to redo the firmware many many times but its always like this. i have tried resoldering the wires around 3 times and always only 3-6 columns work. i have no idea what is causing this.
any help would be appreciated

[zegonix]

not much information to go about. what controller/board are you using? are you sure that you connected to the right pins of the controller (are they all gpios? what are the alternate functions of the pins? ..)? do you have a schematic of your matrix? and please tell me you used diodes!