matrix 12

[riccardo]

 Hi everyone,
 there's a problem here with a matrix 12.
 The nice fellows at Oberheim put a switching power supply into them.
 This power supply does not have any protection when a failure occours
 and the voltages supplied raise in value.
 On mine, it happened that the voltages were more than the double of the
 expected.
 Of course at the moment nothing works except for the power supply which I
 have fixed.
 No capacitors or resistors diodes etc. in a mess, must be some chip.
 As I do not have a clue of the power supply path on the other boards, before
 I start changing all the chips on the main board and on the other ones
 my question is:
 is there anybody who knows these machines well enough to suggest what ICs
 are better to try to change or test first?
 cheers to you all