Hi,
Thanks for the thoughts!
>Check that you've got AC coming into the 12V rectifier and DC coming out.
Confirmed, and the electrolytics on the way are fine too. I believe the figure was around 19 V.
>There's then a fairly simple linear regulator, where a likely suspect would be the pass transistor.
Yes, I too must assume the regular and/or transistor are at fault, because everything before there is fine, but by the time we get to the +12 V supply, it's minuscule. I have ordered replacements of both.
Also, a poor attempt to probe that vreg led to it being shorted, which promptly blew the fuse just before the rectifier in question! Hopefully it works once that fuse finally arrives from HK... It's 1.0 A instead of 0.8, but it'll have to do for the moment.
Another thing that was suggested to me is that perhaps the EL backlight has gone high-resistance and is stealing current from other, more important components. Though I doubt this is the main cause, it certainly won't hurt to cut the traces to the EL's transformer if the regulator/transistor don't fix it. The backlight was already whining, and I find that a lot more annoying than a dim screen, which I'll be using in a lit room anyway!
Thanks again! appreciate the help and any other comments you might have.