If your LabQuest is not powering on at all, that is the power button LED is off and the screen is black, even when connected to AC power, here are some things you can do to troubleshoot the issue.

1) Start by connecting your unit to AC power using the included AC adapter. Leave the adapter connected for at least one minute before proceeding. Press the power button on the LabQuest. (In some instances, the unit will power on as soon as you connect the AC adapter. This typically indicates that your battery is totally dead.) The expectation is that the unit will power up normally. If it does, leave the unit charging for at least 8 hours before trying to use the unit on battery power. (Not sure if your battery is good, see Original LabQuest Battery Troubleshooting and FAQs.)

If the power button LED comes on but the screen stays black, see LabQuest blue power-button LED is on, but the screen is black.
If the screen comes on, but the unit does not boot all the way, see My original LabQuest is stuck on the LabQuest logo screen.
If there is no change, continue on.

2) Verify that your device can receive power from the adapter.
a) Confirm that the AC outlet you are using live.
b) Confirm the AC adapter is working with another unit or has a measurable 5V voltage output. How can I tell if my LabQuest power adapter is good?
c) Check that AC port on your LabQuest has the center charging pin in place.
d) Ensure the reset button, located on the back of the unit, is not stuck behind the casing.

If you have a bad AC adapter, you can purchase a new one. (LabQuest Power Supply (LQ-PS, discontinued))
If the center charging pin is missing, see How do I replace the AC adapter port on an original LabQuest?
If the reset button is stuck, use the stylus to gently reposition the button.
If all of these are fine and your LabQuest still has a black screen and the power button LED is off, continue on.

3) Reset the unit by doing the following…
a) Remove the unit from AC power.
b) Remove the battery from the unit (see How do I remove or replace an original LabQuest battery?).
c) Reconnect to AC power.

The expectation is that the unit will power up normally. If it does, put the battery back in the unit. Verify that you can use the power button to power the unit off and back on normally. Leave the unit charging for at least 8 hours before trying to use the unit on battery power. (Not sure if your battery is good, see Original LabQuest Battery Troubleshooting and FAQs.)

If the power button LED comes on but the screen stays black, see LabQuest blue power-button LED is on, but the screen is black.
If the screen comes on, but the unit does not boot all the way, see My original LabQuest is stuck on the LabQuest logo screen.
If there is no change, continue on.

4) If the unit still has a black screen and the power button LED is off, determine if a different, charged battery can provide power to the unit.
a) Remove a fully charged battery from a unit that is known to work (How do I remove or replace an original LabQuest battery?).
b) Put the working battery into the non-working unit and see if the unit will power up at all.

If the unit does power up, then your unit is not receiving power from the AC port, see How do I replace the AC adapter port on an original LabQuest? for some options.
If the unit does not power up, the unit likely has damage that cannot be repaired and should be recycled. Check with your local recycling center for information about recycling electronic components or check:
http://www.electronicsrecycling.org

If you have any questions or concerns regarding this issue, contact Vernier technical support for further assistance.

Additional Information:
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