Osborne One -- No video.

Hello all, I recently acquired an Osborne One, but it seems to be having a video problem -- as in no video at all. I did the obvious - played with the brightness and contrast -- but still nothing. If I press a key on the keyboard, the floppy starts seeking, so I assume the rest of the computer is at least partially working, but I get no video output at all. I have NO docs or schematics, so it's a bit hard for me to test stuff out. The CRT make no noise at all when power is either turned off or on (no static or hum, or anything else). Also, I took the cover off, and carefully looked inside while turning the power on, and the CRT didn't light up, or have any other response. After powering down, a very careful disassembly showed no physical damage signs -- no burn spots, missing components, broken wires, etc. Any clues? This is the blue case, with the modem, and a composite video jack (female RCA jack) in the bottom right.... Rich B.