This laptop uses mainboard sound chip with Realtek AC97 Audio. When the sound works it works fine, but it sometimes just stops working when you reboot (sound adjustment options are grayed out on Sounds And Audio Devices Properties but the drivers and hardware show as working correctly in Device Manager).
I have uninstalled then reinstalled the current sound drivers several times both in Safe Mode and regular mode. This does not solve the problem when the sound is not working. I have also visually inspected the physical sound chip on the mainboard; all solder joins seem intact and it shows no evidence of generating excess heat.
The issue can usually be fixed by removing the battery, powering down the computer, disconnecting the AC adapter, waiting about 5 minutes, then rebooting. But invariably the sound will stop working again at the next reboot or the reboot after that.
Does anybody have any ideas or options that I haven't tried yet? I would very much like the sound to work all the time on this box, which has been otherwise very dependable.