I'd ask... what video connections does it have? VGA, BNC, SCART, a single Composite video cable? Does it also have separate audio inputs (or no audio, or audio included in the SCART or something)? Does it take any control signal from the monitor, towards the cameras (e.g. for pan/zoom control)?
If it's just VGA (or something else you can easily substitute a regular monitor with the relevant connection), first thing I'd do is see if this other monitor displays. You may need to balance it on the stepladder, for the cables to reach (if you don't have KVM-like VGA extender cables/etc) while testing.
On the whole, though, I can't tell you what the mechanical sounds might be (unless it's an integrated PC with an HDD in it?). I can think of a few electrical 'thunk's that might sound mechanical, but no friction-like sounds. Except for general white noise.
But the blinking power button is very reminiscent of either the primary power converter or the bits that specifically power the LCD backlights malfunctioning. Both mean bits that are repairable/replaceable, if you know how, but I'd go for a direct replacement if you don't. Even then, if you're lucky, all you need to do is get an existing desktop monitor, unscrew it from its stand and screw onto the ceiling mount you'll by now have removed the duff one from, connecting up the (hopefully, being the simplest of all cases) VGA connectors, et voila.
If it's BNC/phono-style composite/SCART/whatever... You can probably get a new unit with that capability as well. Just at more cost, and less likely that one is just "hanging around" in the office.
(Am really assuming you have an LCD/TFT-like display. If it's a CRT one, then it gets complicated. If it's got the integrated camera scanning/recording functions in, then sounds like you need to replace what is effectively the main module. But you should still be able to plump the old camera feeds into it, one way or another, even if you have to rewire or convert somehow. If it's something that has the pan/zoom controls integrated, that might need a bit more shopping around, or hacking a replacement system... Probably best/easiest,then, to go for something newer, anyway, assuming it isn't brand new in the first place.)
[Somewhat ninjaed, I think.]