Problem with Nubytech SFAC Controller

I’ve had one of these (Ken model specifically) for about a year but recently broke it out again and when I play 3S on my PS2 the game will randomly pause (I dont think I am accidentally hitting start because it happens even if I dont hit any of the attack buttons – does happen when I tap the d-pad) but it doesnt happen when I play HSF2 or anything from the Alpha anthology disc.

Does it sound like a loose wire? Is there any way I can open it up and try to figure it out?