XO 1.75 A3 ECOs: Difference between revisions
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==Audio Power== |
==Audio Power== |
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This corrects a wiring mistake ( |
This corrects a wiring mistake (<trac>10974</trac>). |
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* Wire +3.3VA_AUDIO (U24.5) to +3.3V_AVDD (the side of C218 closest to the codec). |
* Wire +3.3VA_AUDIO (U24.5) to +3.3V_AVDD (the side of C218 closest to the codec). |
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==RTC Power== |
==RTC Power== |
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This corrects the inability of the RTC to maintain data |
This corrects the inability of the RTC to maintain data across a power-off (<trac>10999</trac>). |
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* Change R29 (top side of board, underneath the RTC) to 330 ohms |
* Change R29 (top side of board, underneath the RTC) to 330 ohms |
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Revision as of 00:53, 18 June 2011
These are recommended engineering change orders (ECOs) to the A3 prototype of the XO-1.75 laptop. This is NOT a list of changes from A3 to B1, that is located elsewhere.
SMBus Pullups
These correct a mistake omitting the pullup resistors for the SMBus between the EC and the battery charger. It has been done to all boards.
- Add a 1.3K resistor between PR200 and +3.3VSUS (available at PD31, pin 2).
- Add a 1.3K resistor between PR201 and +3.3VSUS.
External SD Power
This corrects a wiring error. It has been done to all boards.
- Tie PQ64.2 to Q22.2
Audio Power
This corrects a wiring mistake (<trac>10974</trac>).
- Wire +3.3VA_AUDIO (U24.5) to +3.3V_AVDD (the side of C218 closest to the codec).
It has not been done to many boards. Marked AUDIO on the tag.
RTC Power
This corrects the inability of the RTC to maintain data across a power-off (<trac>10999</trac>).
- Change R29 (top side of board, underneath the RTC) to 330 ohms
- Add a 10 uF capacitor in parallel with C227
It has not been done to many boards. Marked RTC on the tag.