XO 3 A1 ECOs

  This page is monitored by the OLPC team.

These are recommended engineering change orders (ECOs) to the A1 prototype of the XO-3 laptop. This is NOT a list of changes from A1 to A2, that is located elsewhere.

Fix OTG connector

The pinout on the USB OTG port needs to be swapped.

Done to some motherboards. Motherboards which haven't been modified should have tape blocking the use of the port.

Switch LCD Scan

• Depopulate the 10K resistor in R200.
• Populate R189 with a 10K resistor.

Done to all motherboards.

Fix Audio Jack

We attempted to support TRRS headphones (ones w. integrated microphones) in the headphone jack. Unfortunately, the engineer used the Nokia TRRS headphone/mic spec. instead of the one used by Apple, and as a result the external Mic. jack is crippled. This ECO drops all support for integrated microphones.

• Depopulate R3

Done to all motherboards.

Fix Camera

• Swap an AO3402 into Q9

Done to all motherboards.

Backlight PWM

• Change PR128 to a 1K resistor.
• Populate PC122 with a 0.1uF capacitor

Done to all motherboards.