H132548 - G70 MONITOR SCREEN BLANKS INTERMITTENTLY SYMPTOM: Intermittently, the G70 Monitor screen may blank for about half a second, then return to normal operation while running at 1024x768 with a 75 Hz refresh rate. PROBLEM ISOLATION AIDS: The monitor is a G70 running in 1024x768 @ 75Hz refresh mode. Serial numbers prior to 23-28000 are affected. Only the G70 monitor is affected. The monitor may be attached to any MCI/PCI architecture system which complies with VESA 75 Hz timings specification. FIX: PROBLEM BACKGROUND: The blanking is the result of a Mode Blank signal from the monitor's internal processor. The blank screen occurs when the monitor's count of sync pulses changes, and the monitor erroneously assumes a mode change has occurred. Eleven predefined user modes are pre-programmed into the monitor along with several factory presets. The Factory presets are VESA specified. One of the user defined modes is XGA (1024x768) The monitor counts sync pulses searching for a mode it recognizes, first from the user defined modes, then from the factory presets. When it recognizes a mode, the monitor assumes the image geometry (height, width, etc.) programmed for that mode. Because the difference between XGA mode and VESA 75Hz mode is very slight, the monitor sees the initial mode and compares it to the user defined modes, and may select the XGA mode without checking the factory presets. Once this occurs, the monitor locks into that mode. Since this mode is not an exact fit (and sync sampling continues), the count will occasionally be sampled differently. The monitor then blanks the screen and selects a new mode. It samples the timings again and matches them to the XGA user defined mode, starting the whole process over again. Preventative Actions: XGA timings have been removed from current manufacturing to eliminate the problem. Engineering will continue to examine modes selected for the user defined space to ensure they are not close enough to the factory presets to cause confusion. Permanent Fix: A permanent fix is available from the PC Company Bulletin Board System by calling 919-517-0001, and downloading the following file to reprogram the user defined modes of the G70 monitor: File Name - G70FIX2.EXE (disk image) File Size - 131,553 bytes File Date - 02/16/96 Directory - IBM PC 300/700 Files The instructions that are given at the start of the program MUST BE FOLLOWED EXACTLY. The geometry must be changed for each screen and then wait for more than 5 seconds before going to the next screen. As an interim solution, you can change the refresh rate in the BIOS setup to 72Hz for 1024 by 768 resolution. To do this, any DDC capability of the system will have to be disabled. This may result in a slight increase in flicker, which is why the fix on the BBS is recommended.