Laptop starts for about 1/4 second, then shuts off

[Will T.]

I was browsing the Internet as usual earlier when my laptop abruptly shut itself off. I thought this was just one of those occasional conk-outs that Windows seems to be prone to, but upon trying to turn it back on, I found that I cannot do so. When I press the power button, the power light comes on for about 1/4 second before simply going dark again.

I've tried waiting several minutes between attempts to power it on, both with and without the battery in place during that time. I've even tried starting it with the A/C adapter in, but no battery. No luck.

If it's worth noting at all, the light by the wireless-antenna-toggle button on the keyboard turns on for a split-second right as it's shutting down. Could this indicate that the wireless antenna is the culprit, or at least an accomplice to the crime?

Does anyone have any ideas on what the problem might be? Windows self-updated a couple days ago, and I've known it to completely corrupt itself to the point of requiring a system-restore when doing so in the past; could that be the case here? Is there any way to get into Windows (short of transplanting the HDD into another machine) to restore back to before the bad update? Could it be simply a hardware connection that got knocked out of place or a component that can be easily/cheaply replaced? Is it perhaps time to get a new machine altogether (this one is due for a replacement this winter anyway, but I was hoping to put that off as long as I could)? Thankfully I can write off a new laptop as a school expense and take the $$$ for it out of existing student loans, so a new machine, while far from my favorite choice, is at least a viable option. The comp really picked a bad time to break down - I'm busy all day Monday and start classes on Tuesday - so quick answers would be very much appreciated!

Also, if it's important, the machine an HP Pavilion dv7 running Windows 7, manufactured in late December 2010 and bought at the start of January 2011.

[Boss Llama]

That's definitely not a software issue caused by the update - it hasn't even identified the existence of a hard drive that fast, much less read anything on one. I believe you're probably looking at a dead power supply - the part that is supposed to be feeding the juice to the system is not doing so.

It's a hardware issue that, being a laptop, definitely needs to be worked on by a professional. While it shouldn't go bad that fast from when you got it, and ought to be easily replaceable by a tech with the parts, tools, and knowledge needed, it might take a week or two if you have to send it off for that.

[Will T.]

Based on my tests and research, it does indeed seem likely that it is the power supply ... which unfortunately might be integrated into the motherboard on this model. I'm having very little luck finding anyone selling a good-looking mobo for this specific machine, let alone one with a dedicated GPU on it like mine. (If the power supply is a separate part, there are even fewer people selling those than mobos.) I'm thinking I might just have to put this machine out to pasture a little sooner than expected.

Heading to Best Buy tomorrow to take a look at the current entry in an Asus line that I've been keeping an eye on for a while. Thank goodness I have student loans to cover the cost...