Osborne monitor service information ?

Hi Guys, I have an Osborne-1 with a bad monitor - I have the technical manual, which gives schematics for the main logic board and the disk board, but NOT the monitor. The monitor is a: Zenith model DS5NF3 Symptoms are: Its Powered through a single +12v line on the connector, filiment lights, which suggests power is present. Horizontal drive, vertical drive and video signals are all present on the monitor connector. No light at all, no "buzz" typical of flyback transformer. Looks like horizontal/high-voltage circuit is dead. Unfortunately I have no schematic - At least the only IC on the board is a 555 - hopefully no unobtainium used in this one (unless it's the flyback :-( anyone got diagrams or other service information on a "Zenith DS5NF3" monitor. Suggestions/debug hints welcome - I'm guessing horizontal output transistor or flyback ... [and before anyone asks - yes, this is the one which was missing it's monitor plug, however I have borrowed the plug from a working machine and verified that the signals are getting to the monitor] Regards, Dave -- dave04a (at) Dave Dunfield dunfield (dot) Firmware development services & tools: www.dunfield.com com Vintage computing equipment collector. http://www.parse.com/~ddunfield/museum/index.html