Sony FW Problem

I tried searching, but this is an odd problem to describe, so I didn't get any results.

I have a Sony Vaio FW 190. I recently had to roll back from Windows 7 RC to the original Vista 32 manufacturer install. No problems. I uninstalled a lot of the bloatware, and installed the programs I need. No problems. Let it do all of the updates, including installing SP2. No problems. Finally, I leave my laptop plugged in almost all of the time. I know this is probably not the best behavior, but it is what it is.

Yesterday, I downloaded, installed, and was just starting to play the Bioshock demo. Suddenly, my screen started changing from full brightness to dim and back again, as well as just performing poorly. Thought it was the game, so I got out of it, but the problem persisted.

Noticed that what was causing this was the computer switching from running on battery to running plugged in. We are talking this cycle happening every second: on power, on battery, on power, on battery.

Turned everything off, and unplugged the brick from the wall. Let everything be for a bit. Turned everything back on, same problem. Tried plugging the brick directly in to an outlet, same problem.

So I assumed my brick was dying. However, with the laptop off, I plugged it in this morning, and the battery LED on the front was holding steady, as if it were charging normally. When the computer is on, that same light is switching the same way the screen is, thinking it is getting power, then not.

I have already ordered another brick. However, the fact that it only seems to do this behavior when in Windows has me thinking it is something with the OS. Anyone ever experienced this before? Or have any ideas what could be causing this?

 

Quick update:

It actually starts this behavior from the moment the power switch is pressed and it starts booting up, not from Windows. So probably not OS related. Still interested if people thing it is the brick, or something with the computer itself.

Update Again:
OK, so I was wrong about that. It is right before the login screen appears that it starts going crazy, not while it is booting. So that puts it back in to Windows.

 

i dont think its the adapter. I think its your DC connector. your computer is not getting connection to the adapter. once computer not get charge? power option take over and dim your screen. when you move. computer get connection and the screen go back to full brightness. Power is not stable. possible ac adapter or dc connector. Try move the connector where it plug in on the back of the computer. if the battery icon change from charging to battery? than you know where the problem is.

 

i dont think its the adapter. I think its your DC connector. your computer is not getting connection to the adapter. once computer not get charge? power option take over and dim your screen. when you move. computer get connection and the screen go back to full brightness. Power is not stable. possible ac adapter or dc connector. Try move the connector where it plug in on the back of the computer. if the battery icon change from charging to battery?than you know where the problem is
If you get unstable light flickers on bios? than back light or inverter problem.