Built-in card reader on Acer Aspire 5550
In case you haven’t known it, the built-in 5-in-1 card reader on the Acer Aspire 5550 can only support SD but not SDHC (high-capacity) cards. Although this wikipedia article shows that normal SD card can be as large as 4GB, most of my 4GB SD cards are high-capacity, which can’t be read by the built-in card reader. The same applies for the free USB SD card reader that comes with unit – both can only support SD cards up to 2GB. For the built-in card reader, nothing will happen when you insert an unsupported card. For the USB card reader, attempting to use an unsupported card will result in a continuously flashing red light. On the other hand, when the USB reader does not detect any card, the indicator will flash for 3 seconds, pause for 1 second and flash again.