Everyone here has seen the awesome PO-12 mod with arcade style buttons by allymobs http://www.allymobbs.com/blog/?p=907
u can see pretty clearly what is being soldered to the buttons in the pics on the allymobbs page.
also peep this thread if u haven't already..
that our very own punji has been deconstructing the PO's. lots of good info in there.
also i saw on the youtube video, that ally said that the beat repeat button is just wiring the speaker ground pad to the grounds of all the arcade buttons.
it looks like its not super complicated altho the soldering is tiny parts
@docshermsticks yes thanks mate. it seems pretty straight forward. will heat up the iron and go for it
nice. keep us posted! over the weekend, i actually drew up a quick button layout and stuff for one of my own.
i don't have much experience soldering such small areas, so not sure if I want to jump in w/ the iron yet.
^ That repeat button is connecting the speaker negative pad to the keys common line. That is not a ground signal, but rather a PWM pulse from the codec power amplifier. That could be potentially destructive unless an open collector transistor is added to avoid a short-circuit, given that there is already an output pin driving the common line at ground level.