it powers up without bsi coding just does the beep, with the pp2000 you can just enter the vin to unlock it, is connecting up the speakers to test the cause of the pop noise, i have no spare speakers at the moment but i did manage to do a form of that test, when i had the radio out of the slot but still plugged in i hit it with a bic pen and it reproduced the pop.
I've never tried the unlock thing lozz, but if i have the pp2000 in ill try to delete the characters in the vin bit it might actually unlock the radio, its a good security system but i don't really think peugeot had to do it, the shape of the radio makes it useless in anything but a 406, and you need a display to be able to see what station is playing.
About the soldering, here is the earthing things i resoldered:

what do you think is wrong here, the soldering i do never is as shiny as the original soldering, is something missing?