Asus EEE PC: Remote On/Off
I originally bought my EEE PC intending to use it as an upgrade/replacement for my current Car PC as it is much smaller, consumes less power, and uses a solid state drive (SSD) for data storage (meaning no moving parts while booting the OS and frontend etc).
There were a couple of problems I needed to overcome though - it would not be a case of simply swapping units over.
The first thing I needed to do was figure out a way to connect the EEE PC to my existing M2-ATX PSU so that the ignition was still able to control the PC turning on and off. On the existing system, this is done using a simple connection to the header on the motherboard. When the PSU recieves the ignition signal, it shorts these two pins together and the system powers on.
On the EEE PC, there is no header that I could connect such a lead to, so I had to rip things open and add one myself...
How to Get at the Internals:
- Remove all screws from the underside of the unit
- On the top edge of the keyboard, there are a couple of springy clips holding it in. Use a flat screwdriver to hold these in and prise the top edge of the keyboard out. The whole thing should slide upwards now and will be attached to the main chassis by a thin ribbon cable.
- You can unclip the ribbon cable to get the keyboard out of the way (carefully!)
- With the keyboard out of the way, remove the black screws holding the top half of the chassis down. You don't need to remove the two either side of the screen. There are also a couple of plastic clips on the rear - by the screen pivots. These need prising apart (again - either a flat screwdriver or case splitter will be fine). The cover should lift off, revealing the motherboard.
- There are a couple of retention clips on the bottom side of the motherboard which can be released by sliding the motherboard up slightly. It should pop out.
- The VGA port also needs to be levered slight to release the side of the main board. When this is done, it should come loose and if you remove the mini-plug for the fan connector, the board can be removed entirely.
For the purpose of this guide, I was interested in the power button, located near the right hand side screen pivot point. The images below show the switch with what appears to be 5 soldered connectors. With a bit of testing and a flat screwdriver, I determined that the pins which needed shorting together to initiate turn on / switch off were the top two.
So I went about soldering some fly leads and threading them through the chassis, making them secure so they couldnt be pulled off easily.
Putting the EEE PC back together again and plugging it in / connecting the battery, allowed me to test that it all worked properly. Touching the two fly leads together (same as ignition ON) starts the PC up. Once booted, touching the leads together again initiates shutdown (same as ignition OFF).
Next problem is to sort out is the difference in voltage supplied by the regulated PSU (12V) and the input required by the EEE PC (9.5V). Stay tuned...
September 2nd, 2008 - 02:06
Thanks for the instructions!
A few notes based on when I did it(*):
You only need to remove the 6 outer screws off the bottom of the EEE, no need to remove the panel (or the motherboard later on).
When removing the top cover the audio sockets act as an anchor.
I didn’t remove the motherboard.
The two left-hand pins of the power switch are connected and grounded. The two right-hand pins are connected as well. The third pin at the bottom is connected to the switch chassis and also grounded.
Connecting either of the two right-hand pins to ground will turn the EEE on/off. I ended up with one wire soldered to the bottom-right pin and one to the bottom-center pin.
(*)I _mostly_ did it, I got some help with the soldering
If you’re still looking at a 12V-9V supply I’ve got a circuit based on a 7801 LDO (low-drop-out) regulator which is working well for me. I’d be happy to forward the schematic.