B737 IDG
Guys,
Thanks for the replies.
As i understand it the 'SOURCE OFF' light does not mean the transfer bus is not powered. That is done by the 'TRANSFER BUS OFF' light. The 'SOURCE OFF' means a GCB has opened and an AC TRANSFER BUS is powered from a non normal source.
Say IDG 2 is powering both TRANSFER buses then IDG 1 will have a 'SOURCE OFF' light on.