XO 1.75 A2 ECOs
Revision as of 01:19, 9 January 2011 by Wad (talk | contribs) (Created page with 'These are recommended engineering change orders (ECOs) to the A2 prototype of the XO-1.75 laptop. This is NOT a list of changes from A2 to B1, that is [[XO1.75_A2…')
These are recommended engineering change orders (ECOs) to the A2 prototype of the XO-1.75 laptop. This is NOT a list of changes from A2 to B1, that is located elsewhere.
SD power
These correct a mistake in Embedded Controller pin assignments for the SD power control signals. It has been done to all boards.
- Depopulate R335 and R345 (next to the EC).
- Remove Q16, and short pins 2 and 3 (marked I and O).
- Remove Q16, and short pins 2 and 3 (marked I and O).
VMEM stability
This corrects an undercompensation of the +1.5V memory power supply, and also delays the turn-on of the memory termination power supply. It has been done to all boards.
- Change PR49 to 22K.
- Change PR52 to 47K.
- Populate PC37 with 0.1 uF.
eMMC
This adds a needed pullup to the eMMC CMD signal.
- Populate R95 with a resistor between 4.7K and 10K.
