Troubleshooting Power Issues on the Mesa 3

8 Jun 2023

Use these methods to troubleshoot specific power issues with the Mesa 3 tablet. To troubleshoot general problems, refer to Mesa Windows or Mesa Android.

Charge Indicator Is Uncalibrated

For the charge indicator to accurately show the status of the internal and removable batteries, you must calibrate the charge indicator. When the charge indicator is uncalibrated, the battery may appear to never fully charge or appear depleted when it still has some charge left.

To calibrate the charge indicator, fully charge the battery and then fully discharge it. Repeat the calibration process as needed.

Battery Is Unbalanced

An older Mesa 3 battery may become unbalanced, requiring the battery to be updated then recovered. For instructions, see fixing an unbalanced battery.

New Battery Does Not Work in Tablet

Before inserting a new battery into a Mesa 3 tablet, update the firmware and OS on the tablet. If you add a battery with firmware version 7A to a tablet with outdated Embedded Controller (EC) firmware (version 1.24 or lower), the tablet may lock up or flash the red light three times when you press the power button. (For more information on battery firmware and EC firmware compatibility, see Swapping Batteries between Tablets.)

To fix this problem, remove the new battery. Perform a 20-second shutdown (or remove the power source and drain the internal battery for at least 12 hours). Update the tablet's firmware and OS before re-inserting the new battery.

Flexible Card Retainer Not Fully Seated

Make sure the flexible card retainer is fully seated, as shown in the following images. Problems with the flexible card retainer may prevent the battery from engaging.

Mesa Card Retainer

Mesa 3 Android Not Powering On

If a Mesa 3 Android unit will not turn on, plug in a 30 W wall charger and a powered USB-C cable (only for a second) simultaneously. If this works, make sure updates are installed. (See also Mesa 3 Android stuck during boot.)

Wall Charger Or Other External Power Source Not Correct

The Mesa 3 tablet (or dock) requires a 30 W or higher power supply with a 12 V output to power the tablet and charge the batteries at the same time. An older charger (such as, a Mesa 2 charger) will not work properly with a Mesa 3. For details, see Old charger will not charge newer product model.

You can also try testing with a spare charger or from another unit. Make sure the external power source meets the requirements. (See Power Input Requirements and Limits.)

Electronically Disconnected Batteries

A Mesa 3 unit may not immediately turn on if the battery pack(s) have been electronically disconnected (for example, after a hard reset). To recover a unit that is in an electronically disconnected state, make sure the main removable battery pack is inserted properly in the unit, attach a 12 V 30 W or higher power source, and then briefly press the hardware power button.

Over-Discharged Batteries

If a Mesa 3 doesn’t turn on, batteries are not appearing to charge, or the unit is not seeing the battery pack(s), the batteries may be over-discharged.

To repair overdischarged batteries,

Plug in the tablet.
Power off the tablet by pressing the power button for a few seconds and selecting Power Off or Shut Down. Do not select Restart.

Caution: Make sure the battery is within a recommended temperature range (about 68°F or 20°C). Batteries will not charge (or charge slowly) at temperatures below 32°F (0°C) or above 122°F (50°C).

Leave the tablet plugged in overnight.

Note: Initially, the system will slowly trickle charge the severely depleted battery pack(s). Eventually, the red light flash slowly, indicating that the battery has recovered and is charging normally again.

When the battery reaches 40% capacity, the tablet may respond to pressing the Power button. However, Juniper Systems recommends fully charging the tablet batteries.

To avoid over-discharged batteries, leave the tablet plugged in overnight and on weekends as recommended. If you are not using the tablet daily, store the unit and batteries properly, as instructed in the Mesa 3 manual.

For additional information on battery care, see Mesa 3 Battery Not Present or will not charge to full.

Door Magnet

Make sure the door magnet is not missing or weak. See Mesa 2 will not recognize or charge batteries.

Loose Charging Port

The charging port may be loose or damaged. To determine whether the port is damaged, charge the battery using a dock, another Mesa 3 tablet, or an external battery charger. For repairs, fill out the Repair Order Form.

Replace Battery

If the removable battery has unbalanced cells or another problem that prevents the battery from fully charging or being detected, remove the battery and insert a spare battery or one from another tablet.