View Full Version : [ubuntu] Acer Aspire 5515 (ATI gfx) w/Jaunty: backlight issue in X only

August 18th, 2009, 06:28 PM
I've got an Acer Aspire 5515 running dual-boot Vista and Jaunty. This notebook uses the ATI X1200 chipset for video. Last night I encountered an odd issue where the monitor backlight was permanently dimmed. I believe this happened when I had the monitor dimmed (case almost entirely closed) and ran out the battery power. After that the backlight stayed off, but only in X. If I switched out to a terminal (ctrl-alt-F#) the backlight would come on fine. During startup and shutdown the Ubuntu logo and progress bar showed up fine (that's framebuffer, or whatever it's called, I assume?) And when I booted into Windows running at the same resolution as X, the backlight came on fine. There's a lot of different backlight issues for different brands of latop, different kernel versions, etc, etc. I poked around the net and tried some things, but nothing seemed to work. I've accidentally discovered a klugey fix: By editing xorg.conf to load a non-existent video driver, I can trigger the "error" menu whereby X starts up in some low-res VGA mode and gives you troubleshooting options. Selecting "Reconfigure for this system's hardware" (or whatever it's called) and then editing xorg.conf again to go back to the "radeon" driver allows me to restart X with the backlight on. Since I don't plan on regularly letting the battery run dry without shutting the machine down first (much less doing so with the case almost-closed) this solution is probably good enough for me. But I spent enough time poking around on the net that I'm curious now whether there's a "real" fix for this issue or not. (Or is it even on radar? Should I submit a bug report?) Also, is there any way to get to the X troubleshooting menu without "forcing" X to fail by pointing it at a nonexistent driver?