Part of screen goes black, intermittently

[Hoov]

Look on the motherboard and see if there are any long connectors that are on the motherboard that are near the back of the computer running straight toward the front. If there are, tell me what color the plastic of the connector is.

[Poet8]

Sorry for the delay.  The black patch hadn't happened for a while.  Here are two photos of it on the screen (just about half an hour ago).  Strangely, when I closed the Firefox window, the black patch completely disappeared.  I.e., it didn't stay on the screen when I went to the wallpaper of the desktop.

Also, here is a photo of the motherboard.  If I understand you correctly, there seem to be a few long connectors -- two beige and one green.

Thanks.

[Hoov]

Does it only happen when you have Firefox open?

[Poet8]

That's hard to tell.  Lately, yes.  But I vaguely remember maybe the first time it happened it transferred to the wallpaper too.  But I can't remember for sure.  Lately it has only seemed to be while in FF, though.  Sorry I can't remember more specifically.

[Hoov]

Try using Chrome or Safari for a while and see if it happens again.

[Poet8]

Sorry for the delay -- I was trying to see if it would happen in Chrome, but I was not able to duplicate the problem.  It seems to start when I am in FF.  I can't remember if it then persists on the screen when I close FF or not, but it has definitely always started in FF.  Of course, that is usually what's on my screen most the time anyway.  But, again, it hasn't happened with Chrome these last 4 days.  Any thoughts?  Thanks.

[Hoov]

What plug ins and themes do you have installed?

[Poet8]

I use the default theme.  The plug-ins listed are for Adobe Acrobat, Google Earth, Google Update, Java Deployment, Java Platform, Microsoft DRM, Mozilla Default, Quicktime, various RealPlayer, Shockwave Flash, Silverlight, and Windows Media Player.

[Poet8]

UPDATE:  Within about 3 hours of switching back to FF, the black splotch has reoccurred.  It seems to begin in FF, and then carry over to whatever other window I click into.  For example, if I am in FF and the problem happens, then it follows into Word, into Chrome, and when I minimize all windows, it remains on the desktop wallpaper some of the time but not in every instance.

[Hoov]

Try running Firefox in safe mode.

1.  Close down Firefox completely: At the top of the Firefox window, click the File menu, and select the Exit menu item.

2.  In Windows, click Start, open the All Programs list, and navigate to the Mozilla Firefox folder. In the Mozilla Firefox folder, select Mozilla Firefox (Safe Mode).

3.  Firefox should start up with a Firefox Safe Mode dialog.

4. Click Continue In Safe Mode. This starts Firefox in its Safe Mode. While you are in Safe Mode, your extensions and themes will be disabled, and any toolbar customizations will be reverted back to their defaults. These changes are not permanent - when you leave Safe Mode and start Firefox up normally, your extensions, themes, and settings will return to the state they were in before you entered Safe Mode.

[Poet8]

Running FF in safe mode for the rest of night was fine -- the blacked-out area did not return, at least as of yet....

[Hoov]

I would say the next step is to start FireFox normally, and then go into the addons and disable all of them. After restarting Firefox, if it runs good that way, then start reactivating the addons and see which one causes the problem.

[Poet8]

OK, will try it.  But don't I need some of them?  For example, if I need to open a pdf as a web page and I've disabled the Adobe Acroboat add-on, won't that mean it won't work?

[Hoov]

Exactly, but if the plug-in is malfunctioning, then it probably isn't working anyway. This is the way to find out what the problem is.

[Poet8]

Now I think I'm having a problem with Adobe Flash -- when I was investigating what the various plug-ins were, just so I'd know what I was disabling, I came across an Adobe page which suggested I update to the latest version of Flash, which I did.  However, then I noticed that it came with something called PlusPlus and a McAfee security scan (the latter I didn't want and uninstalled through Add/Remove Programs).  I also read that Plusplus was not desirable and so disabled that new add-on.  Then later, when I tried to play YouTube, YouTube would not work -- the video portion was just a black screen.  So I tried to troubleshoot Flash -- I uninstalled and reinstalled, but YouTube still does not play.  When I reinstalled Flash there was no Plusplus this time.  I supposedly have the latest version installed, but I'm wondering why YouTube won't play.  Also, at one point during this process, a black box similar to what was going on before (but much smaller) blacked out the Flash Installer icon on my desktop.  I don't understand what's happening, but feel that, one -- I've messed things up somehow, and two -- given the blacked-out Flash icon, maybe it was a bad version of Flash that has been been causing this problem all along?  Is that possible?