LinuxQuestions.org - curious black lines on screen, just started appearing

I've been running a full-install Puppy 5.28 on this machine trouble-free for about a year now, (and very happy with it!) but have encountered a problem today which is making life virtually impossible.

The problem seems to be specific to this installation; I have other OS's on this machine which are starting normally, and I am at this moment working normally in an instance of Puppy loaded from a live CD, so I feel reasonably sure it's not the hardware that's the problem.

When switched off last night, everything working normally, and I have done no recent fiddling with any settings, so the fault is apparently spontaneous. My screen is showing random vertical and horizontal black lines, sometimes angled ones, sometimes fanned ones, occasionally a small black box. Initial screen display on starting up builds very slowly indeed, and icons take a long time to appear, and are sometimes corrupted. When I click on any icon or work through any menu, any response takes a good 30-60 seconds, which makes me think that all the system resources are being soaked up by the system's efforts to put something sensible on the screen?

The only thing it's occurred to me to try is to run Puppy's XOrg 'Wizard', which probes the hardware and reports back that everything should work normally. The wizard exits the X session to do its work... it's when it restarts X that things go wrong again.

Hugely grateful in advance! In the forlorn hope that it might help, here is my xorg.conf

Code:



#Special base config file used in Puppy Linux.



# **********************************************************************

# Module section -- this  section  is used to specify

# which dynamically loadable modules to load.

# **********************************************************************

#

Section "Module"



# This loads the DBE extension module.



    Load        "dbe"          # Double buffer extension



# This loads the miscellaneous extensions module, and disables

# initialisation of the XFree86-DGA extension within that module.

    SubSection  "extmod"

      Option    "omit xfree86-dga"  # don't initialise the DGA extension

    EndSubSection



# This loads the font modules

#    Load        "type1"

#    Load        "freetype"



# This loads xtrap extension, used by xrandr

#  Load      "xtrap"



# This loads the GLX module (if present). xorg 7.4/5 need explicit disable to disable...

    Load    "glx" #LOADGLX



# This loads dri module (if present). 7.4 loads it by default, have to disable...

  Load      "dri" #LOADDRI

#    Disable "dri"



EndSection



# **********************************************************************

# Files section.  This allows default font paths to be set

# **********************************************************************



Section "Files"



# Multiple FontPath entries are allowed (which are concatenated together),

# as well as specifying multiple comma-separated entries in one FontPath

# command (or a combination of both methods)



    FontPath  "/usr/share/X11/fonts/misc/"

    FontPath  "/usr/share/X11/fonts/Type1/"

    FontPath  "/usr/share/X11/fonts/TTF/"



EndSection



# **********************************************************************

# Server flags section.

# **********************************************************************



Section "ServerFlags"



# Uncomment this to disable the <Crtl><Alt><Fn> VT switch sequence

# (where n is 1 through 12).  This allows clients to receive these key

# events.



#    Option "DontVTSwitch"



# Enables mode switching with xrandr

# There is a report that this can cause Xorg not to work on some

# video hardware, so default is commented-out...

# but i want to use it in xorgwizard so leave on...



    Option "RandR" "on"



# With this, Xorg won't talk to HAL to add evdev devices and you'll be back

# with the old Xorg behavior (pre-7.4)...



    Option "AutoAddDevices" "false"



# For no-Hal, kirk also suggests this...



#    Option "AllowMouseOpenFail" "true"



# Xorg 7.4, Ubuntu Jaunty, CTRL-ALT-BACKSPACE is disabled by default...



    Option "DontZap" "false"



EndSection



#everything past here is auto-generated by Puppy's Xorg Wizard...





Section "ServerLayout"

        Identifier    "X.org Configured"

        Screen      0  "Screen0" 0 0

        InputDevice    "Mouse0" "CorePointer"

        InputDevice    "Keyboard0" "CoreKeyboard"

EndSection



Section "InputDevice"

        Identifier  "Keyboard0"

        Driver      "kbd"

        Option      "XkbRules" "xorg"

        Option      "XkbModel" "pc102"

        Option      "XkbLayout" "gb" #xkeymap0

EndSection



Section "InputDevice"

        Identifier  "Mouse0"

        Driver      "mouse"

        Option            "Protocol" "IMPS/2" #mouse0protocol

        Option            "Device" "/dev/mouse"

        #Option      "Emulate3Buttons"

        #Option      "Emulate3Timeout" "50"

        #Option      "ZAxisMapping" "4 5" #scrollwheel

EndSection



Section "Monitor"

        Identifier  "Monitor0"

        VendorName  "Monitor Vendor"

        ModelName    "Monitor Model"

        HorizSync    31.5-100

        VertRefresh  59-75

        #UseModes    "Modes0" #monitor0usemodes

        Option      "PreferredMode" "1440x900"

        EndSection

        

Section "Modes"

        Identifier "Modes0"

        #modes0modeline0

EndSection



Section "Device"

        Identifier  "Card0"

        Driver      "nvidia" #card0driver

        VendorName  "nVidia Corporation"

        BoardName  "NV44A [GeForce 6200]"

        BusID      "PCI:1:0:0"

EndSection



Section "Screen"

        Identifier "Screen0"

        Device    "Card0"

        Monitor    "Monitor0"

        DefaultDepth 16

        #Option        "metamodes" "1440x900_60 +0+0" #METAMODES_0

        Subsection "Display"

                Depth      16

                Modes      "1440x900"

        EndSubsection

EndSection



#PuppyHardwareProfile=NVIDIA