Note: Do not use a Hard Reset except as a last resort such as when both the screen and hard keys are not responding. This is equivalent to turning off a computer by yanking out the power cord instead of shutting it down.
For other options, see:
TIL 1777: How do I reboot or reset a LabQuest?
TIL 1688: Original LabQuest Troubleshooting and FAQs (Full List)
1. To perform a hard reset, put the stylus on the reset button (see image below)
2. While looking at the face of the LabQuest, press and hold the reset button for 15 seconds. The blue power light should turn off while you are depressing the reset button.
3. Release the reset button. The LabQuest should boot normally.
If the blue power light does not go off at all, see: TIL 2087: LabQuest will not reset when I depress the reset button.
If the blue power light goes off, but the unit does not reset, remove the battery, wait at least one minute, then replace the battery. See TIL 2189: How do I remove or replace a LabQuest battery?
The reset button is located on the back of the unit, to the right of and above the battery door, just below the stylus sleeve.
TIL 2077: Original LabQuest Battery Troubleshooting and FAQs