PVL Burning out

[cmtstu]

Hello all
I finally pulled out the MZ ive had in the shed for years, it was given to me because the previous owner couldnt get a spark from it. after taking apart i found that the PVL TSZ (pickup unit) had burned out, i checked through wiring and from what i can tell it is correct but when i put a new TSZ unit on it burnt it out again within a few seconds, can anyone sugest what mite be causing this problem?

Thanks