A quick Google search on "dell 510m backlight" reveals the inverter
probably needs replacement -- that's a hardware item. Several repair
services appear under the same Google search, you might want to contact
them.

You either have a bad lamp or a bad inverter. If the screen has a
pinkish tint, it is probably a bad lamp. Sometimes one of the wires
comes loose from one end of the lamp, which also causes the inverter to
shut down because it senses an overcurrent condition. The strange part
of your problem is the length of time the lamp stays on before shutting
down. Usually a bad bulb or a defective inverter will cause shutdown
within a second or two, not a minute or so.

At any rate, if the problem is a bad inverter, they are pretty easy to
replace by removing the bezel around the LCD panel. It is located
inside the lid below the bottom of the panel, and plugs into the video
cable on one end, and the lamp plugs into the other end. You can get
the inverter on Ebay, similar to item #190261086678.

If the lamp is defective, it is not replaceable without taking the LCD
panel apart or doing some creative cutting and grinding, and the usual
solution is to replace the complete panel.

Good points, and it looks like we both hit on the inverter being the
likely source of the problem, but, as you wrote, the one-minute time
is strange.

If the backlight was marginal and the display pinkish, I'm sure the
OP would have mentioned that.

To see how to open up and make repairs to the 510m, the owner's manual
and service manual are here:

<support.dell.com/.../index.htm>

I've ordered a new inverter and will see how it
goes.

Just as a follow up - I can get my display to work (for long enough to
be practically useful, at least) by turning the brightness right down.
I assume this is putting less of a stress on the components, so they
don't shut down. Anyway, it works well enough for now, so I'm happy(ish).

I am using Ubuntu 9.10 and have a Nvidea video card. I installed the
proprietary drivers offered by Ubuntu for this card and my display
changed resolution so bad that I cannot change it via the gui. Is there
any way to change it by cli?

Restart your computer and choose the second option which is the recovery
mode. You may need to press escape to see the options.
It will bring up a text mode menu which allows reconfiguring several thing
including display settings.

I had a problem where the display was set so low I couldn't see the tabs
on the change display box. I got around this by using orca
(screenreader). It read whatever button I had tabbed to and I was able
to hit enter and do what I wanted.

I'm having a similar problem, try this and report if you have success:
ttps://answers.launchpad.net/ubuntu/+question/92953
It brings up nVidea GUI which is easy to configure as you want.

I also have NVidea card and 9.10 of Kubuntu & Ubuntu (duo boot) and they both
gave resolutions up tp 1280x... after the installation. That was UNTIL I
installed the NVidea driver. That's when the problem starts; highest resolution
becomes 1024x. I can use the NVidea util to change the resolution but it is lost
when rebooted.

In previous versions of Kubuntu, I did modify xorg.conf but this doesn't work
with 9.10. The nVidea util, even under sudo, fails to save changes.

BTW, I'm using the oldest NVidea driver; x96 due to the age of my card/computer.

Nvidi cards have given me issues with Kubuntu Karmic (9.10) also but it has
been inconsistent. On a 128 bit card at least 2 years old it works
magnificently at 1600 x 900, however on another computer, AMD 64, a new PCIe
card won't save the resolution and tops out at 13xx by 7xx (can't recall
exact figures) both using the non-free Nvidia drivers!
That isn't the most puzzling display issue I'm working on however. On my 2
year old MSI Wind U100 every version of 9.10 I've tried (Ubuntu, Kubuntu,
Ubuntu, Mint etc) has the 'flashing brightness' problem that never occurred
with any previous Ubuntu, or any other distribution. Yes I have searched
the forums and net extensively but have only found partial and temporary
solutions. Before I start to move (temporarily) beyond the Ubuntu family I'd
like to appeal for help with this.

I'm sorry you've had trouble... i've had the same and it's beyond my
knowledge to help. I'm using 8.04 while i test another distro.