If the service guide does not cover localized features specific to your region, you should contact your regional Acer office or the responsible personnel/channel for further technical details.

The flickering is normal due to the nature of the fluorescent light. To resolve this, turn off the Power Switch and then turn it on again. The flicker should disappear.

An afterimage is a normal occurrence with LCD screens, especially if the same image is displayed for an extended period. To recover the screen, change the image or turn off the Power Switch for a few hours.

If you see an 'Out of Range' message on the screen, it means the input signal is out of the supported range. The OSD will display this message within 5 seconds, and the LED will be green. Ensure that the input signal resolution is within the maximum supported resolution of 1440x900.

If the screen shows 'No Signal' and the LED is green, it indicates that there is no input signal from the selected input source. The OSD will display this message within 8 seconds. Check the input source and connections to resolve the issue.

The Acer AT1921 monitor supports various resolutions and refresh rates, including 640x350 at 70Hz, 720x400 at 70Hz, 640x480 at 60Hz, 800x600 at 56Hz, 800x600 at 60Hz, 800x600 at 72Hz, 800x600 at 75Hz, 800x600 at 85Hz, 1024x768 at 60Hz, 1024x768 at 70Hz, 1024x768 at 75Hz, 1280x720 at 59.86Hz, 1280x720 at 74.78Hz, 1360x768 at 59.8Hz, 1360x768 at 74.89Hz, 1440x900 at 59.89Hz, and 1440x900 at 74.98Hz.

During the disassembly process, group the screws with the corresponding components to avoid mismatch when putting back the components.

First, check the VGA cable to ensure it is connected correctly. If the cable is fine, check the input P2 at the motherboard. Specifically, verify that pin 13 (H-sync) and pin 14 (V-sync) are functioning correctly. If these are correct, check the PC for any issues. If the problem persists, consider changing the motherboard.

To find the correct part number, you should check the most up-to-date information available on your regional web or channel at http://aicsl.acer.com.tw/spl/. If you are an Acer-Authorized Service Provider, use the local FRU list provided by your regional Acer office to order FRU parts for repair and service of customer machines.