paf@murdu.OZ (Paul Fritze) (07/25/86)
Does anyone know of a source for the Mac analog board line output transformers? Apparently the early version (black) transformers have proved a common cause of board failure - 3 of ours out of 20 failed in the past year (2 this week!) - seems a pity to send a board back when the cause is known. These failures were characterized by assorted crackling, dead or flashing screen and smoke from the LHS vents - the BU406 driver transistor (on the heatsink to the front) was shot in one case and cooking in another. In the last failure, sparks could be seem emanating from the transformer. Another problem characterized by dead screen and ticking noise was caused by shorted diode on heat sink immed. in front of transformer causing 12V supply to fail. The newer apparently reliable transformer (grey) in the latest Mac+ supplied to us is marked: MONITRON 157 0026-B made in Taiwan -- Paul Fritze ASCnet: paf@murdu UUCP: {seismo,mcvax,ukc,ubc-vision}!munnari!murdu.oz!paf ARPA: munnari!murdu.oz!paf@seismo.css.gov CSNET: paf%murdu.oz@csnet-relay