The lights do come on, it's just that the ones that come on are (o) = lit, ( ) = not lit ( ) Power OK ( ) Over Voltage (o) Over Current (o) +2.5V Fail ( ) +5V Fail (o) Reg Fail ( ) Over Temp (o) Power Have the printsets now, will probably take both units apart for Inspection and cleaning. John -----Original Message----- From: Peter Turnbull [mailto:pete@dunnington.u-net.com] Sent: Thursday, November 07, 2002 2:45 PM To: cctalk(a)classiccmp.org Subject: Re: 875 Power Controller/H7104C 2.5VDC PSU/H7104D 5VDC PSU On Nov 7, 13:43, John Willis wrote: The Field Maintenance print sets for the PSUs and the power controller are available at http://208.190.133.201/decimages/moremanuals.htm (part of the DFWCUG Historical CPU Preservation Society). They are BIG files. If an 875 power controller is like an 876, then if the lights don't come on, reset your breaker :-) I don't know about the H7104's (I've never seen one up close). I assume there is something plugged into the 3-pin Power Bus connector, or you have the three-way switch in the "local" position, otherwise it won't turn on. -- Pete Peter Turnbull Network Manager University of York