TFT Display scrolls or slides when mouse at edge of screen

TFT Monitors Picture scrolling side to side or up and down problems are common when connecting a new display for the first time.

The usual way to configure a TFT monitor is to connect it and start the computer, then go to the display properties as shown on the Basic Checks page and select the highest possible resolution, however if the monitor is connected to a working system - it may not check the resolution of the new screen until re-started.

This will usually be the native resolution of the TFT monitor - and the correct resolution to select. However - some display adaptors allow a higher resolution to be selected than the monitor is capable of - and then they display only part of the whole screen area on the monitor - moving it accordingly when the mouse approaches the edges of the screen.

The whole effect of this is very disconcerting when seen for the first time (and the second and third time too!) - but it should be understood that it is the PC that is panning the screen (actually Windows and the display driver) - NOT the monitor, which is simply displaying the part of the screen as instructed by the PC.

This is important to realise because no amount of adjusting the monitor will resolve the problem! - The display settings need to be changed to the correct native resolution of the monitor, as usual.  The monitor will then display the whole picture correctly and it can then be adjusted as normal.

Some LCD and Plasma Televisions fitted with PC analogue inputs do NOT work correctly!  Some have been found to incorrectly return their resolution to the PC, resulting in difficulty in configuring the display settings:

The Relisys RTL3000 (30" TV / monitor circa 2005) for example has a 1280 x 768 display resolution - but declares it's resolution as 1024 x 768.  If the connected PC is set to 1280 x 768, the screen scrolls horizontally to accomodate the extra width.  Also, pictures are distorted as the Relisys stretches the 1024 pixels displayed to the full width of the screen.  The only option is to override the monitor settings and force 1280 x 768 resolution and manually adjust the graphics card settings until an acceptable picture is obtained.  This was possible with an ATI Radeon card - however a two pixel border could not be avoided.

Some other models have been found to revert to a stretched picture format after every power off/on, requiring a manual re-configuration on the remote control to correctly display from a PC.  The effect of this is seen clearly with the vertical stripe test pattern displayed.