Hello
This is my first post after numerous hours of searching for a solution.
I have a 1711M NEC TFT monitor. I encountered 2 problems:

1. Sometimes when Mandrake 10.0 boots the display is displaced 1 inch aprox. to the right.

This problem is more or less fixed automatically by the auto button of the monitor. I had the same problem with SuSE 8 but not with RedHat 8.0.


2. After I connect as a user everything seems OK, but after a short while-variable time duration- the monitor display "corrupts" with lines and specks. What you can see is a general layout of the windows and icons but you cannot recognize them. The same behavior I got with SuSE 8 but not with RedHat 8.0.

I have tried
logging again: no solution
restarting: temporary solution. Starts same tricks again
changing a lot of different sets eg 800x600, 1024x768 etc but nothing seems to work

any suggestions out there?

The "offset" is due to your display not being set properly for the video resolution which is being output by the machine.

The auto button indeed attempts to correct this.

This is UNRELATED to the second problem, the display corruption.


The second problem occurs because the kernel or driver is overwriting the video frame buffer.

This can be due to an errant driver, the wrong driver selected, the driver not knowing how much video ram is available, the wrong agp driver, or the agp driver not knowing where the i/o mapped address space is.

You didn't post your machine specs, but if you have an integrated display (UGH THESE STINK for the most part!) chipset then this can also be due to a bios setting...

e.g. the AGP aperture size

being wrong for Linux.

Thank you for your time to reply.
Unfortunately i don't yet know how to find the appropriate information for my system. I copied from the herware list the info about my graphics card, so here it is:

Vendor: ‎nVidia Corporation

Bus: ‎PCI

Bus identification: ‎10de:171

Location on the bus: ‎1:0:0

Description: ‎NV17 GeForce4 MX 440

Module: ‎Card:NVIDIA GeForce4 (generic)

Media class: ‎DISPLAY_VGA

I think this info is not enough but I will try to search and learn how to provide more info. This is just to tell you that I need some time to figure that out...

I came up with an idea but I don't know if it is relevant or not. If I change my grapgical server from Mandrake (default) to KDE would that help? (I use KDE as my desktop environment).

Where do you think shoult I start reading from?

You should start by posting your machine specs and configuration, not just the graphics card.

While the Nvidia MX 440 is no powerhouse, it does work fine in Mandrake.

However this video card did not always tolerate faster AGP data rates, so you may need to crank down the AGP settings in your system's bios and turn off sideband addressing and write combining.

Sorry for delaying so much to reply but I tried to find a better way of posting pc specs than copying from the hardware list -didn't so far- so i list nVidia card, processor and AGP bus from the hardware list (that was all I could see it was relavant, but i may be wrong. So here they are:


Vendor: nVidia Corporation

Bus: PCI

Bus identification: 10de:171

Location on the bus: 1:0:0

Description: NV17 GeForce4 MX 440

Module: Card:NVIDIA GeForce4 (generic)

Media class: DISPLAY_VGA




Bogomips: 3563.52

Cache size: 256 KB

Coma bug: No

Frequency (MHz): 1800.924

Cpuid family: 6

Cpuid level: 1

F00f bug: No

Fdiv bug: No

Flags: fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 mmx fxsr sse syscall mmxext 3dnowext 3dnow

Is FPU present: Yes

Whether the FPU has an irq vector: Yes

Halt bug: No

Model: 8

Model name: AMD Athlon(TM) XP 2200+

Processor ID: 1

Model stepping: 1

Vendor: AuthenticAMD

Write protection: Yes




Vendor: VIA Technologies Inc

Bus: PCI

Bus identification: 1106:b168

Location on the bus: 0:1:0

Description: PCI-to-PCI Bridge (AGP)

Media class: BRIDGE_PCI


Additionaly I went throught my mobo, graphics card and TFT monitor manuals.

Observing more the kind of abnormal behavior of my monitor exhibited I saw that this was more or less a slight displacement of vertical lines (not all the way from top to bottom) and these slight displaced lines had different colors according to background and icon. Trying to see an asf movie on Totem Movie Player I saw that it had vertical zones with no image at all).

According to my monitor manual this is due to wrong vertical frequency setting, so I started playing with specific settings proposed on the monitor manual, not with much success. What I observed was that with different settings the time before the abnormal behaviour occured could vary from a few minutes to roughtly 3 hours. At the moment I have:
1024x768
24bpp
VF 75 Hz
HF 60 Hz
The monitor is set to Plug'n'Play as a custom setting
So far (2 hours) I have encountered no problems but.....

I also tried to follow your suggestions on BIOS settings after reading carefully my mobo manual.
I found no sideband addressing setting but I thing I found something on write combining.Here are my initial----->final settings
(again everything that appeared to me as useful):

Graphics Aperture Size [64MB] (my graphics card has 64MB)

AGP Compatibility [AUTO] [4x graphics card, 1x-2x-4x-AUTO the posibilities]

AGP Performance Control [Disabled]

AGP Fast Write Control [Disabled]

Video Memory Cache Mode [USWC] -----> [UC]
USWC Uncachable, Speculative Write Combining
UC UnCachable

Delayed Transmission [Disabled]

For your information, first I made the BIOS setting change from USWC to UC and then started to play around with the frequencies, which as iI mentioned earlier proved unsuccessful so far. This means that my BIOS settings change had no effect to my problem.....

Do you have any suggestions what to read so I can try to fix it -if it is not yet fixed whith my last frequency setting, which I thing will not work as well eventually.

Thanks again for your time and iI hope you reched reading to this point.....

Best regards

Graphics Aperture Size [64MB] (my graphics card has 64MB)

If your system has 512 megs of memory you may want to increase this to 128 megs


AGP Compatibility [AUTO] [4x graphics card, 1x-2x-4x-AUTO the posibilities]

Set to 1x get things working, then move it up to 2x.

AGP Performance Control [Disabled]

Hmmm. this may be toggled later.

AGP Fast Write Control [Disabled]

Good for testing

Video Memory Cache Mode [USWC] -----> [UC]
USWC Uncachable, Speculative Write Combining
UC UnCachable

OK

Delayed Transmission [Disabled]

Turn ON


"Observing more the kind of abnormal behavior of my monitor exhibited I saw that this was more or less a slight displacement of vertical lines (not all the way from top to bottom) and these slight displaced lines had different colors according to background and icon. Trying to see an asf movie on Totem Movie Player I saw that it had vertical zones with no image at all).

According to my monitor manual this is due to wrong vertical frequency setting, so I started playing with specific settings proposed on the monitor manual, not with much success. What I observed was that with different settings the time before the abnormal behaviour occured could vary from a few minutes to roughtly 3 hours. At the moment I have:
"

As you are seeing changes in the colors of these bars, this has nothing to do with monitor timing and EVERYTHING to do with the original problem, that the driver is overwritting the frame buffer.

Is your card plugged into an AGP slot or PCI one?

What type of motherboard do you have and what is it's chipset?

What Nvidia driver are you using?

What AGP driver are you using under Linux?

Hallo again.

Strangely enough I have no problems (yet) with my monitor. I tried to have a crash test session yesterday and it behaved well for 7 hours continuously. Odd!

Refining my remarks on the abnormality the parallel short length displaced color lines DO NOT change color over time. Their color is stable. Also scrolling down a document I get a fynny scroling of a "shadow" of my text right or left depending on my scrolling down or up, as if the text wraps from the right part of the screen to the left and vise-versa.Now I see how incomplete was my first description.....Sorry about that...



Coming to your remarks:

"Graphics Aperture Size [64MB] (my graphics card has 64MB)

If your system has 512 megs of memory you may want to increase this to 128 megs"

My system has 256 MB of physical memory.I left it to 64 MB



"AGP Compatibility [AUTO] [4x graphics card, 1x-2x-4x-AUTO the posibilities]

Set to 1x get things working, then move it up to 2x."

Things seem to work right now and thats why I kept it to AUTO but if anything goes wrong (again) I will bear this change in mind as a first option countermeasure.



"Delayed Transmission [Disabled]

Turn ON"

I did that although description of the feature says that this refers to a PCI Delayed Transmission (I have an AGP graphics card, slotted on an AGP bus)



"Is your card plugged into an AGP slot or PCI one?"

AGP



"What type of motherboard do you have and what is it's chipset?"

(info deducted from mobo manual)
MOTHERBOARD: ASUS A7V8X-X
CHIPSET: Northbridge VIA KT400
Southbridge VIA VT8235



"What Nvidia driver are you using?"

(info deducted from /etc/X11/XF86Config-4)
Section "Module"
Load "dbe" # Double-Buffering Extension
Load "v4l" # Video for Linux
Load "extmod"
Load "type1"
Load "freetype"
Load "glx" # 3D layer
EndSection

Section "Monitor"
Identifier "monitor1"
VendorName "Plug'n Play"
HorizSync 31-82
VertRefresh 56-75

# Sony Vaio C1(X,XS,VE,VN)?
# 1024x480 @ 85.6 Hz, 48 kHz hsync
ModeLine "1024x480" 65.00 1024 1032 1176 1344 480 488 494 563 -hsync -vsync

# TV fullscreen mode or DVD fullscreen output.
# 768x576 @ 79 Hz, 50 kHz hsync
ModeLine "768x576" 50.00 768 832 846 1000 576 590 595 630

# 768x576 @ 100 Hz, 61.6 kHz hsync
ModeLine "768x576" 63.07 768 800 960 1024 576 578 590 616
EndSection

Section "Device"
Identifier "device1"
VendorName "nVidia Corporation"
BoardName "NVIDIA GeForce4 (generic)"
Driver "nv"
Option "DPMS"
EndSection

Section "Screen"
Identifier "screen1"
Device "device1"
Monitor "monitor1"
DefaultColorDepth 24

Subsection "Display"
Depth 8
Virtual 1024 768
EndSubsection

Subsection "Display"
Depth 15
Virtual 1024 768
EndSubsection

Subsection "Display"
Depth 16
Virtual 1024 768
EndSubsection

Subsection "Display"
Depth 24
Virtual 1024 768
EndSubsection
EndSection



"What AGP driver are you using under Linux?"

I don't know how to provide this info. Searching through all files I found this directory:
/sys/bus/pci/drivers/agpgart-via
inside there were small files with names as in the first coloumn and content as the second column following-these I managed to make a readable vi out of:

class 0x060000
detach_state 0
device 0x3189
irq 0
resource 0x00000000f8000000 0x00000000fbffffff 0x0000000000001208
0x0000000000000000 0x0000000000000000 0x0000000000000000
0x0000000000000000 0x0000000000000000 0x0000000000000000
0x0000000000000000 0x0000000000000000 0x0000000000000000
0x0000000000000000 0x0000000000000000 0x0000000000000000
0x0000000000000000 0x0000000000000000 0x0000000000000000
0x0000000000000000 0x0000000000000000 0x0000000000000000
subsystem_device 0x807f
subsystem_vendor 0x1043
vendor 0x1106

I don't know if this is relative or sufficient info but it is the best I managed to do.....


I just had a nasty repetition of the monitor problem -after about 2 hours of normal behaviour.

The only thing I changed from yesterdays troublefree monitor operation was the Delayed Transmission feature which I enabled.

Troubleshooting:

1. I left it enabled to see if this was coincidence and observed monitor behaviour:
It exhibited the same problem again in 15 minutes time.

2. Changed Delayed Transmission back to my troublefree configuration (Disabled).
It exhibited the same problem again in 15 minutes time. I rebooted and it lasted for about an hour.

3. Changed Delayed Transmission back to your suggestion (Enabled) and set AGP Compatibility to 1x.

I will continue monitoring and get back.........

Thanks a lot for keeping up and helping me out on this.......