|
4.769 bytes |
Service Hints & Tips |
Document ID: YAST-3NYT4C |
IBM Monitors - Two fine horizontal lines on certain displays
Applicable to: World-Wide
Service Information:
The phenomenon descibed in the attached text occurs also on the 9521 Display. The Tension Mask used manufactured by Mitsubishi is similar to the TRINITRON CRT described below and the horizontal lines are NOT a product defect.
In some application panels, two fine horizontal lines may be seen across the screen locatde approximately one third and two thirds of the distance from the top to the bottom of the screen. The lines can be seen in the test raster (Signal Cable Disconnected).
These lines are due to the CRT technology used in the 8517, 9517, 6553, 6554, 6555, and 9521 monitors. See additional information onTrinitron monitors below. This is NOT a defect of the CRT. The CRT should NOT be replaced if these lines are detected. This information is also provided for the customer in the "Guide to Installing and Using" document that was shipped to the customer with the monitor.
Trinitron:
Developed by the Sony Corporation of Japan, Trinitron CRTs are markedly different to conventional CRTs. Most noticeable is the fact that the CRT is completely flat in the vertical plane and only slightly curved in the horizontal plane. The Trinitron does not have a conventional shadow mask. Instead, it has an aperture grille, formed by an array of tensioned vertical wires. In order to ensure correct spacing of these wires there are usually one or two horizontal tie wires which keep the vertical wires in position.
These horizontal wires may be just visible as thin dark lines across the picture when a bright uniform screen is displayed. These lines can sometimes be confused with being part of the image. Although this may cause concern when using the monitor for certain applications, such as CAD and desk top publishing, this is a normal phenomenon for ALL Trinitron CRTs, not just those used in IBM monitors, and does not indicate a defect.
Advantages:
1. Doming cannot occur on Trinitrons under normal conditions as the tensioned wires simply relax slightly under bright screen conditions and do not move.
2. Trinitron CRTs have a radically different electron gun assembly design compared to conventional CRTs. This tends to give a smaller spot size and hence better focus performance.
3. The other main advantage of the Trinitron is that it produces considerably more brightness, for the same beam current, than a conventional CRT. This is due to the higher transmission of its aperture grille.
4. Arguably, Trinitron CRTs give better convergence performance than conventional CRTs.
Note: The 6553 Monitor has only one wire and will show only one line.
SAS KEYWORDS:
PSY2 PSY2DISP D/T9517 D/T8517 WIRES 9517 8517
D/T6091 6091 D/T9521 FTSGNK
|
Search Keywords |
| |
|
Hint Category |
General Information | |
|
Date Created |
05-10-95 | |
|
Last Updated |
20-01-99 | |
|
Revision Date |
20-01-2002 | |
|
Brand |
IBM Monitors | |
|
Product Family |
Personal System/2 | |
|
Machine Type |
8517, 9517 | |
|
Model |
All | |
|
TypeModel |
| |
|
Retain Tip (if applicable) |
H046232 | |
|
Reverse Doclinks |