Mog

We have got 3 iMacs for home and business use in the house and all of them are constantly looking for the network, internet is ok but can drop out when looking for network which can be a prob when air dropping etc for files. We have got a TP Link router which has been changed and a Extreme time machine which is also giving problems on one machine.......Help as apple tech are useless.

Markus

Ok, a few questions:
1. What OS X version, or versions are the macs running, ideally they should all be on the same version unless there are reasons this cannot be done

2. Make sure that the Time Capsule (assume that is what you mean by extreme time machine) is running the latest airport firmware it can.

3. What is your network topology? In other words, where does the internet connect. I'm taking a guess it's probably into some kind of router (what type / make / model), which is then connected via ethernet cable to the time capsule and it's the time capsule that is providing the wireless network (I am assuming all these machines are connecting wirelessly, rather than wired).

4. What is the setup of the wireless network (is the network name / SSID visible?) what channel is it using (or is it set to auto) is it set to b / g / n (or a mix of some sort), what encryption is it using (WEP / WPA / WPA2) is a password configured on it? Is it setup to serve out DHCP addresses (or is something else, the router perhaps) configured to do that?