Handheld computer (display) will not turn on

29 Mar 2011

If the handheld computer (display) will not turn on, try the following solutions.

Check battery and charger

Make sure the battery has enough charge to boot up the Field PC. Also make sure the charging cable or docking station is actually providing enough power to charge the Field PC.

You may want to use a voltmeter to make sure the battery is outputting the proper voltage (such as 3.6 volts for the Allegro battery). If the power output is less than specified, you may need to purchase a replacement battery. The battery may have exceeded its 500 full charge cycles life expectancy, developed memory (mainly older NiCAD batteries in our legacy Polycorder and Fieldbook products), or over-discharged (mainly NiMH batteries for Allegro models).

Maintain the battery by plugging in the Field PC (or placing in the Power Dock) every night and weekend.

Adjust display contrast

The Transmissive LCD (display) on the Mesa Rugged NotePad and the monochrome LCD on the Allegro Field PC can potentially have the backlight brightness or contrast adjusted to the point where nothing is visible on the display. Adjusting these back to normal using the hardware keys as described in the user guide may resolve the issue.

Reset the software (Warm Boot)

Press and hold the Power Button (On/Off key) for 5-7 seconds. If a Power Button menu appears, release the Power Button and tap Reset from the Power Button menu. If a "Warm Reset Detected" screen appears on an Allegro CX Field PC, release the On/Off key. The display should flash and the Field PC should begin to reset.

Reset the hardware and restore the software (Cold Boot)

You can try pressing and holding the Power Button (On/Off Key) for 20 seconds. If you encounter a "Power Button" menu or a "Warm Reset Detected" screen, continue to hold the Power Button until the Field PC resets automatically. This should reset the hardware and restore the software (cold boot), causing the display to flash and the Field PC to begin reloading the operating system.

If the above solution does not help or does not apply to your Field PC model, please follow the instructions on our website at:

Remove Power and Restore System

Check the Touchscreen and Keypad

Make sure nothing is pressing against the touchscreen like a field carrying case or a worn, creased, or shriveled screen protector sheet while trying to turn the Field PC on. Also, make sure the area around the keys are free of debris. If you are using an Allegro Field PC, make sure no key is stuck under the plastic keyboard bezel (which you can lift using the notch at the bottom) or a keyboard label overlay.

Examine your touchscreen for wear or damage. If there is a dent or scrape in the outer layer of the touchscreen, the unit will need to be returned for repair. Please fill out our online RMA Request Form.

If you found an issue with the touchscreen or keypad and were able to fix it, reset the system by pressing and holding the On/Off key for 5-7 seconds until the display goes dark. The Field PC reboots after a few seconds.

If the Field PC still does not turn on after trying these solutions, try the following:

Replace Connector Module (Mesa, Archer, TK6000 only)

The Mesa Rugged Notepad, Archer Field PC, and TK6000 each have a field replaceable module which contains all connector ports including the charging port (DC Jack). A replacement can often be ordered through our online store or by contacting support@junipersys.com. Printed install instructions are often included with the replacement kit, though an electronic version is also available under the Support >Documentation > Accessory and Maintenance Guides listing for each product.

Send to Repair Center

A product can be shipped to a certified repair center as listed at the following web page.

Locate a Repair Center