I need the full network info. What is the modem? Make and model.
How is the TC connected and in what mode.. ie router or bridge?
You still did not give a version number of the TC. Please give me the A1xxx (x is number) from the base.
eg. A1355 is the last one with 1TB disk.. that is gen3
A1302 is gen2 and A1254 is gen1
All of these are now out of warranty and if the earlier ones start blinking.. well I would simply say replace it .. it is too old.
Gen 3 can be worth working on a bit.. but from Mavericks it is hard.
Reset to factory.
Universal Factory Reset.. any model TC or AE.
Unplug your TC/AE from power or turn off at the power point.
Hold in reset. and power the TC/AE back on.. all without releasing reset and keep holding in for about 10sec. (this is often difficult without a 2nd person or a 3rd arm).
Release it when the status light flashes rapidly. If it doesn’t flash rapidly you have missed it and try again.
Note..
Be Gentle! Feel the switch click on. It has a positive feel.. add no more pressure after that.
TC/AE will reboot after a couple of minutes with default factory settings and will wipe out previous configurations of the router.
No files are deleted on the hard disk in a TC.. No reset of the TC deletes files.. to do that you use erase from the airport utility.
Change the naming.
Give it all short names.. this is most important for Mavericks.
ie TCGen3 as base name.. and use different names for each band.. TC24ghz and TC5ghz.
If it starts to blink amber there is a fault.. please immediately go to the airport utility and find what is the fault being reported.
We need that info to work further.