Ok i have an old Melcom st600 panel and a very old bell box that stopped working 2 years ago so i decided to change the bell box as it was crumbling off the wall (picture supplied). I swapped the old bell box for a Texecom premier 1E and wired it up but this is not working as well, i have a 4 core cable and was told to put the red wire to the 12v and the black to the bell, then use blue and yellow for the tamper (picture supplied). Melcom st6000 picture also supplied. I have checked the 3 fuses in the Melcom ST6000 panel and all ok, so I'm a bit puzzled.