Education Technology

Solution 11141: Re-Establishing a Connection Using the Black TI Connectivity Standard A To Mini-B USB Cable After Failed OS Upgrade on the TI-84 Plus Family of Graphing Calculators.

Why can't a connection be re-established using a black TI Connectivity Standard Mini-A to Mini-B USB cable after a failed OS upgrade on the TI-84 Plus family of graphing calculators?

If the error message "Cannot establish communication" appears after an OS transfer failed, the calculator may no longer have a usable OS installed. The OS transfer may have failed because of dead batteries in the calculator, the cable was inadvertently disconnected and/or PC processor-intense activities were running during the OS transfer. At this point, the calculator will rely solely on the boot code to operate and communicate with the PC.

The black TI Connectivity Standard A to Mini-B USB cable must be plugged in after the boot code screen (i.e. "Waiting...Please install calculator software now") is initialized.

To re-establish a connection between the PC and calculator, try the following:

• Unplug USB cable.
• Turn the calculator OFF (by removing one battery).
• Re-insert the battery and turn calculator ON (by pressing [ON]).
• Plug the USB cable into the calculator.
• Start the OS download within the next 50 seconds.

Windows® may report an attached USB device has malfunctioned. If the calculator goes to the error screen (Press any key to turn unit off. Then turn unit back on) before the transfer starts, try the steps above again.

If the calculator has a corrupted OS (i.e. won't power on with good batteries), it may take a few extra steps to get to the boot code screen. Try the following procedure:

• Hold down the [DEL] key.
• Remove any AAA battery Wait a few seconds.
• Reinsert the battery.
• Release the [DEL] key.

The calculator should now display the boot code screen.