[clug] Ubuntu 8.1 on Toshiba Tecra black screen problem]

[Hal Ashburner]

>> Hal, I'm interested in the unjamming you accomplished with IBM magic  
>> firmware keys, though I don't know if Toshiba has anything like that...
>>     
I'm sorry I didn't see this until now.

On the IBM thinkpad  Fn + F3, Fn + F4 & Fn + F7 do magic things. Turn 
off the screen backlight, send the box to sleep and do something with a 
second monitor attached respectively.
My backlight was out accross reboots, regardless of FC10, knoppix or 
NetBSD being booted. Mashing Fn + F3 while in the bios magically brought 
it back to life where, touch wood (he says knocking his head) it has 
been ok since.

ACPI is dark, nasty magic that I don't understand involving turing 
complete forth interpreters in the kernel and other such hideousness and 
can be pretty painful.
I notice acpitool has a --Toshiba switch which will "show supported 
Toshiba ACPI extensions (LCD brightness level, video out routing, fan 
status)."
I'd definitely have a bit of prod there before cracking the case, but 
that's me, soldering irons scare me silly. :) perhaps some variant on
% sudo acpitool -l 7
will do something useful for you. I think it's at least possible that 
some bug in the hideous acpi stack has blanked your monitor by setting 
something non-volatile that needs to somehow be reset. The fact that you 
do get some kind of light out of the thing for a brief instant makes me 
suspicious of the hardware failure diagnosis - but hey, I've been wrong 
about things I've been more confident about than that.
I wish I could be more use to you.

One option might be to post your extensive and carefully written 
descriptions to a kernel acpi mailing list and just ask "Does this sound 
like a hardware fault or something you might have seen in your travels 
and know how to prod effectively?" Those hackers have seen a hell of a 
lot of laptops. Occasionally they have the reputation of being a bit, 
um, how to put this, maybe "abrupt" is the right word. I doubt they 
would be with regards a question with a genuine attempt to include all 
the right info the way you seem to do it. Just don't take it personally 
if they say something like:
"Hardware fault, goodbye." That info is still just as useful as if 
they'd been more polite about it. Maybe I'm being prejudiced and they're 
nothing but charm and kindness.

Best of luck.
Hal