We have lost the default password for Aten Master View 1216A KVM Switch Password. How to retreive the same?

SOURCE: Password reset for ATEN kvm switch

If you are unable to perform an Administrator login (because the Username and
Password information has become corrupted, or you have forgotten it, for
example), there is a procedure you can use to clear the login information.
To clear the login information do the following:
1. Power off the CN8000 and remove its housing.
2. Use a jumper cap to short the jumper on the mainboard labeled J6.
3. Power on the switch.
4. When the front panel LEDs flash, power off the switch.
5. Remove the jumper cap from J6.
6. Close the housing and power on the CN8000.
After you start back up, you can use the default Username and Password (Login: administrator, pass: password).

SOURCE: Lost the instructions for the CS62U switch

here is the link to the aten website.

http://www.aten.com/download/download.php#productGuide

go to the select quick guide section and locate the model # in there,
p.s. its cs not c5

SOURCE: My Altusen Aten CS62U-2 Port USB KVM Switch seems

It very well could be just a cable causing this problem, try switching around the cables to see if you can isolate the issue. It could be the KVM is not compatible with your monitors refresh rate though, I have seen this happen a good number of times. It will work but will blink randomly to allow the monitor to re-sync with the video card.. . I have a monitor currently on a kvm that does this exact thing. You may want to try another KVM if you can't get it narrowed down to certain cables.. there is a chance the actual KVM is causing this issue, but is not defective, it is just at a different frequency then the monitor.

Thanks so much
Tim

SOURCE: I have an Aten CS62US

Reading a manual would be more useful, and if not please find out how to do configure the hot keys of a kvm switch at kvmstuff.com.

SOURCE: I have Aten USB KVM

You can check out here- there's a lot many Aten usb kvm switch, check your model and find out how to resolve your problem http://www.kvmstuff.com/server-management/kvm-switches/usb-kvm-switch.html