Connection issue for one Mac on our network

First time poster...so be gentle.

We have DSL, and a wireless network in our home using a Time Capsule. I have a new iMac G5, my wife has a MacBook Pro and upstairs is the older iMac G5 our kids use (all running OSX 10.5.8). I never have connection issues with my G5 (it sits right next to the Time Capsule). My wife's MacBook never has connection issues (it's usually in the next room, but also works upstairs). The iMac upstairs occasionally gets a weaker signal.

But the problem is that the upstairs iMac now cannot access the internet or printer over the network. It's got the wifi signal fine, but it "Cannot locate a wireless device on this network..." This happened once before but I can't for the life of me remember exactly what I did to fix it- thought it was a one time deal, in one ear out the other. Bygones. I do remember it taking hours of digging into the bowels of discussion forums before I found a solution. Not so this time.

Anyway, I did a hard reset on the Time Capsule, to no avail. I connected the Time Capsule directly to the old G5 via an ethernet cable, hoping it would kick out an IP address, to no avail.

System prefs/Network diagnostics indicate the following status:

Airport (green)
Airport settings (green)
Network settings (yellow)
ISP (red) failed
Internet (red) failed
Server (red) failed

What do I need to do to fix this?

And here are a couple rhetorical questions that are more just frustration than a request for answers:

• What can I do to make sure it never, EVER happens again? (although I will write down the steps to fix it this time).
• Why does it happen only to the old G5?

Thanks for any help.

Itchy Dog said:

...
• What can I do to make sure it never, EVER happens again? (although I will write down the steps to fix it this time).
• Why does it happen only to the old G5?

Thanks for any help.

Click to expand...

• Not Possible - routers, modems, network cards, wireless cards, cables all fail as does the software controlling it all become corrupted, not to mention ISP outtages....
• Because it is upstairs from the router would be my first response - typical issue in this scenario

1st thing to do is reset all the devices.
unplug the modem for 30 seconds and plug it back in
unplug the TC for 30 seconds and plug it back in
do a full shut down the G5 and then boot up

next create a new user account and see if the issue is system wide or is a problem only with the existing user account

Bobtomay gave excellent advice. If you make a new user account and it works, then you know it's an issue with your normal account. If it still does not get an IP, I still feel it's an OS issue as it's affecting both WiFi and Wired. I can't see both chipsets dying at the same time!

Let us know on especially a new account and we can take it from there if it does not help. Also just to be sure, you might put in the OSX DVD that came with the machine and hold down the Option key at the startup sound. When the choices come up, select Apple Hardware Test and run that. See if it finds any bad hardware.

bobtomay said:

• Not Possible - routers, modems, network cards, wireless cards, cables all fail as does the software controlling it all become corrupted, not to mention ISP outtages....
• Because it is upstairs from the router would be my first response - typical issue in this scenario

1st thing to do is reset all the devices.
unplug the modem for 30 seconds and plug it back in
unplug the TC for 30 seconds and plug it back in
do a full shut down the G5 and then boot up

next create a new user account and see if the issue is system wide or is a problem only with the existing user account

Click to expand...

Thanks for the info, Bob...however, I did all that and the old G5 still cannot connect. Same issues. And I actually moved it into my office so it's sitting right next to my machine and the Time Capsule. A fleeting part of my memory tells me I had to do something to get the TC to release an IP address to the G5 last time, but it's hazy at best...

When you hardwire the iMac G5 to the router, are you sure DHCP is selected in network in the System Preferences? Have you tried hitting Renew the IP Address? On 10.5 it's under Advanced once you are in Built In Ethernet.

dtravis7 said:

When you hardwire the iMac G5 to the router, are you sure DHCP is selected in network in the System Preferences? Have you tried hitting Renew the IP Address? On 10.5 it's under Advanced once you are in Built In Ethernet.

Click to expand...

I did this.
The IPv4 address begins with 169.254....

On My machine the IPv4 address is 10.0.1.2

the 169.254.x.x is an address that the OS assigns when it can't get an IP by DHCP. Did you open advanced and hit renew the IP under DHCP? Does it still come up with the 169 one?

dtravis7 said:

Bobtomay gave excellent advice. If you make a new user account and it works, then you know it's an issue with your normal account. If it still does not get an IP, I still feel it's an OS issue as it's affecting both WiFi and Wired. I can't see both chipsets dying at the same time!

Let us know on especially a new account and we can take it from there if it does not help. Also just to be sure, you might put in the OSX DVD that came with the machine and hold down the Option key at the startup sound. When the choices come up, select Apple Hardware Test and run that. See if it finds any bad hardware.

Click to expand...

Sorry, I missed this post before responding to your second post.
OK, so I inserted the OSX disk and held the option key down on startup. I never got a choice to select hardware test- just clicked an arrow pointing right. When I did that it went through some sort of cycle, made a loud fan noise, then the normal desktop appeared and now it can connect to the internet, the printer, etc. It's still hardwired, fyi.

I assume this is a good thing, although I have no idea what I just did ; )

dtravis7 said:

the 169.254.x.x is an address that the OS assigns when it can't get an IP by DHCP. Did you open advanced and hit renew the IP under DHCP? Does it still come up with the 169 one?

Click to expand...

Yes, that is exactly what I did.

One more thing u might want to check - see if the DNS numbers are showing up in the Network settings of upstairs iMac, if not might be worth adding them per this.

Well, whatever worked didn't last long. 2 days and the upstairs mac is back to the same problem. Any ideas on how to extend the success of the remedy?
Is it just because the mac upstairs is far from the aiport/wifi signal?

Well, whatever worked didn't last long.

Click to expand...

What did u do that gave you 2 days? Go down that path and u may have an eureka moment.