motor controller burned out

Submitted by Roman on Wed, 07/20/2011 - 00:34

Hi all.
Does anybody know if there is a circuit diagram of the vectrix motor controller available anywhere?
Also a partial diagram would help.
The center stud of the three motor connection studs has come loose , overheated and caused the PCB to burn black around the stud.
Unfortunately it has also burned the small IC right next to the "CAP1 1" labeled muRata capacitor.
The IC that is missing looks exactly like the "U18" right next to the "CAP 2" labeled muRata.
The big Bussmann 125A fuse was not blown.
I think the damage was just caused by the temperature of the arcing stud and not actually by a electrical short circuit or blown FET inside the IGBT.
The 3 motor connector outputs on the IGBT do not measure a short in between them and also no short circuit to the negative and positive input connectors of the IGBT is present, I believe the IGBT module is OK.
My question is: what is the small IC that is burned away and where does it suppose to connect to?
Any help would be great.

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vectrix motor controller