Sangram

That'll teach me to do math after a dose of Norval - of course you're right.

Two 4V 2.6AH batteries in series, connected the input of the 4015. Output goes to GPIO, use at least two ground and two hot pins.  Before connecting set the 4015 to output 5.1V with a 1 ohm, 10 watt resistor across the output terminals. If you have a big enough resistor (20w at least), use 0.47-0.5 to simulate a 2 amp current draw. You can get 2+ hours out of this at full load, more at reduced draw. **Edit - this math is wrong, was corrected few posts below***
 
Remove your dummy load and hook up the Asus. I use a powerbank with a Little Pi Zero as a portable media player and headphone amp (not using Armbian for this). Powerbanks are usually quite variable in quality, so you might get a lemon. The 4015 is at least reliable.

First time hearing of it, looks like another misadventure by Asus and will end in a badly coded TinkerOS which cannot install even basic stuff like Samba properly.
 
I would really have liked to see USB 3.0. The additional performance of the 3288 is lost in thermal throttling (which they have done nothing about) and the very strange choice of micro-USB for power input - which also they did not do anything about except specify that the cable needs to carry 3A - yet to hear of a possible candidate. None promise more than 2.4A, and most of them can't even do that. They offer OTG support in the micro-USB port but that's the only way to power it, and no PC will give 3A on a USB port.
 
It's typical of Asus to continue their knee-jerk launches without fixing the underlying problems in the architecture. I know they're not rocket scientists but come on!
 
I do have mine running stable 24x7 but that is only with a top quality cable and a fan blowing air directly across the board. Oh, and because I'm not using their stupid OS, I chose Armbian.

Well, my personal opinion is this is most likely a "more complete" Tinker board with some of the originally intended functionality completed.  For instance all the pins on the 2x2 header next to the microUSB now have a purpose, eMMC, etc.  
 
For thermal, I installed a much broader heat sink that still manages to fit under the hats.  It is not perfect, but is much better about throttling.  
 
For power, you can power it via the GPIO.  For testing purposes I still use the microUSB, but for running it as a user it is strictly GPIO.  The system rarely has issues with undervoltage, but the USB devices will suffer when the 5.0 volts becomes 4.75 or lower.  If possible get a 5.25 volt supply, to give more safety factor against voltage drop.

I download it from here:
http://downloads.slimdevices.com/nightly/?ver=7.9

The exact command list:
wget http://downloads.slimdevices.com/nightly/7.9/sc/70b0c7c/logitechmediaserver_7.9.1~1515516449_arm.deb dpkg -i logitechmediaserver_7.9.1~1515516449_arm.deb After installation is done, WEB control is accessible on http://your_tinkerboard_ip:9000
 
Worked for me. Debian Stretch. Type lsb_release -a (since sprunge.us is currently down and I actually can't see anything)
No LSB modules are available. Distributor ID: Debian Description: Debian GNU/Linux 9.3 (stretch) Release: 9.3 Codename: stretch  

You could install a desktop on top of this ... but rather start with this: https://dl.armbian.com/tinkerboard/Debian_stretch_next_desktop.7z

Or there is something wrong with your network? Are you try to use the wireless network for this?? Please check/provide:
 
1. Is your server already downloading something
2. Did you notice this right after install? We are downloading package base updates in the background in the first run
3. Results of network testings.
 

Remember that you are using a mainline (NEXT) kernel which does not have all functions yet. If you want them, you need to use a default/stock kernel, found in Android or TinkerOS, which is anyway not recommended for this case. And for many others as well. You can switch kernels back and forth in armbian-config menu.
 
 

And few network tests with Tinkerboard Ubuntu Xenial desktop 4.14.14, logs: http://ix.io/EHC

Connected with onboard wireless:
after connecting a wired network