Router will not turn on at all - power lead checked and OK. Before total loss of power router would come on briefly then turn itself off

1. when the unit is powered on, hold down its reset button for 30 seconds
2. while still holding down the reset button, unplug the router from power and hold for an additional 30 seconds
3. still holding down the reset button, turn on power to the router again and hold for 30 more seconds

After this process (a total of 90 seconds) is complete, your router should be restored to itsfactory default state. Note that your particular router may not require the full 30-30-30 procedure. For example, some routers can at times be hard reset after only 10 seconds and without power cycling. Nevertheless, I still recommended memorizing this 30-30-30 rule as a general guideline. When the router restarts, point your browser to http://192.168.1.1 (or maybe http://192.168.0.1). Username and password are likely admin/admin, or admin and no pass. You should not need a manual but here is a link to it just in case http://static.highspeedbackbone.net/pdf/D-Link-DIR-615-Manual.pdf

Have you updated your firmware on your Archos 101? If you can get to a public wifi hotspot like at a McDonalds or Starbucks you should be able to download the latest firmware (you can force the tablet to check for it by going to Settings - About Device - Firmware Update).
The latest firmware included several fixes for WiFi issues that previous firmware versions struggled with.
I would try that, attempt to connect again at home, and if it's still not working switch your troubleshooting focus to the router itself.

> fast answer

Turn the router off.
Disconnect the electrical power from the router.

Reconnect the electrical power.
Turn the router on.

It should immediately "reboot" itself, and "talk" to your Comcast modem, and connect to the Internet.

ping your router with a packet length strength. To do the ping test, go to Start-Run and type CMD and hit enter. Then, in the Command Prompt Window type in the following

ping 192.168.0.1 -l 30000 9

I suppose the 192.168.0.1 will be the default gateway of your router. To check which is the default gateway of your router you can double click the connection icon on your PC, and click the Support tab. You'll see the degault gateway IP third on the list.

Now, if it pings back all three times with times below 100ms then ok. If it doesnt then reduce the ping length to 20000, if again you have losses then reduce it again to 10000. If the ping loses packets and response is slow you'll probably need a new power cord.
If the pinging is ok at 30k then you'll probably need to change the LAN cable that leads from your internet connection onto the wifi router.
To verify this, run this command

ping google.com -l 10000 and see if you have any losses. If you do have losses, then do a ping like this

ping google.com -l 32000 if you again have losses in the ping then you'll need to change your LAN cable because the 32kb packet is almost a standard size of packets and it should have no problems to get through the router, unless the LAN cable is bad.

Hope this helps. Please vote a Thumbs Up if you found this useful and informative.

Connect the router to a UPS to prevent temporary loss of power issues. Any electronics store will carry a UPS that won't cost you a lot.

your router is broken.

After you click 'SAVE', the router will restart itself.
While it is restarting, it briefly disables its Ethernet ports,
and your computer will report "not connected".

Wait 60 seconds, while the router finishes its restart,
and those Ethernet ports will be re-enabled,
and the pop-up balloon on your computer will close itself.

Try unplugging the router and holding down the RESET button in the back of the router down for 10 seconds...then try to power it back on. Can you also try plugging the power supply into another socket?

If nothing changes then either the power supply went out or the router itself just died.

Most are covered for a year so hopefully you kept the receipt.

restarting constantly indicates a loss of connection with the server
talk with your service provider to check the connection for continuity

First thing to do here is to press and hold the reset button of the router for 30 seconds and check if the light will be normal if still the same a firmware upgrade is need for this router............