Problem with Ethernet on iMac

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scottmso

Limp Gawd
Joined
Apr 15, 2004
Messages
380
My parents have a G4 iMac that has recently been having problems with its Ethernet adapter. The Internet would run very slowly downstream - it would get about 100 Kbps when it should be around 3-5 Mbps. But the upstream is about 500 Kbps, which is what it should be. (I must note that it works fine for all other computers on the network)

Here's the thing - when I connect to a Wi-Fi router with the AirPort card it works completely fine. This seems to indicate that it must be a problem with the Ethernet adapter. What exactly might it be? I didn't see any configuration problems that may have caused it. I was also thinking that it might be a hardware problem with the Ethernet adapter, meaning that they would need to buy a new motherboard for it? Any other suggestions to what might cause this? (btw I'm not really too familiar with Macs)

Any advice is appreciated - thanks!
 
perhaps an OS X reinstall would do it? I'm not sure........strang issue you have there.
 
Does your imac have os9 on it as well? If so boot into that and try the nic. If it doesn't work in that then it may be a bad nic. Another option would be if you have another power pc bases mac in the house. If you do boot it in target disk mode and use a firewire cable and boot your mac off its hard drive. That can also help you knock out software issues.

If it comes down to a bad nic just find a usb nic or something.
 
swatbat said:
Does your imac have os9 on it as well? If so boot into that and try the nic. If it doesn't work in that then it may be a bad nic. Another option would be if you have another power pc bases mac in the house. If you do boot it in target disk mode and use a firewire cable and boot your mac off its hard drive. That can also help you knock out software issues.

If it comes down to a bad nic just find a usb nic or something.
Click to expand...

I'm not exactly sure - I know for sure that it never ran OS 9 alone because it's a G4 (flatpanel) iMac. But don't all versions of OS X come with the "classic" OS 9 mode? Is that what you're talking about?

And we do have an old G3 iMac that has OS 9 on it. I'm pretty certain that the newer Macs can't boot the old OS's, right? (I used to use Macs a lot before OS X and that was the way it was back then...) My dad (away from home) has a G4 iBook - would it be pretty easy to boot off of that when he comes back? Or would it be tricky (kinda like booting a Windows install off another PC :D)
 
I want to say that all of the g4 imacs support os9 but it has been a while.

Anyway all you need to do is either use the ibook or the g3 if the g3 has firewire. You hook up a firewire cable between them and turn on the extra mac and hold down t for target disk mode. This turns the other mac into an external hard drive. Then turn on this imac holding down option to bring up the boot menu and tell it to boot off the other macs hd. It is much easer then it is with a pc.
 
swatbat said:
I want to say that all of the g4 imacs support os9 but it has been a while.
Click to expand...
all g3 and g4's support Classic. Its the G5 and intel's that have problems running it. OSX also comes with Classic installed by default i think on a G3/4 based machine.
 
I'd try creating another user, log in as that user and see what happens. I'd also check to see that the iMac is using the same DNS servers as everyone else.

The other thing I'd do is to plug in one of the machines that tested fine to the cable/port the problem iMac is currently using. It well could be the cable and/or port on the switch that the iMac is using.

Classic Mode isn't going to help with your problem since it is simply going to grab the TCP/IP settings from the OSX side. If you really want to go through OS9 to troubleshoot the problem, you'll need to boot the machine to OS9.

Buzzard> iMac G4/G5s support Classic Mode just fine. Intel iMacs do not support Classic Mode at all.
 
CreativeMac said:
I'd try creating another user, log in as that user and see what happens. I'd also check to see that the iMac is using the same DNS servers as everyone else.

The other thing I'd do is to plug in one of the machines that tested fine to the cable/port the problem iMac is currently using. It well could be the cable and/or port on the switch that the iMac is using.

Classic Mode isn't going to help with your problem since it is simply going to grab the TCP/IP settings from the OSX side. If you really want to go through OS9 to troubleshoot the problem, you'll need to boot the machine to OS9.

Buzzard> iMac G4/G5s support Classic Mode just fine. Intel iMacs do not support Classic Mode at all.
Click to expand...

I already tried using another user, no difference there. When I was talking with my (somewhat Mac-savvy) dad about this he suggested that it might be a DNS issue too. However it looked like it was getting the same DNS servers from the router that it should. And I seriously doubt that it would act like it is acting just because of DNS server issues. (i.e. if it is just downloading sites slowly then it is probably resolving the domains properly anyways)

I'll make sure to try the cable thing as there's a (small) chance that could be it, as well as booting it off another disk. Thanks for all of the advice!
 
In addition to the cable, I'd try another machine at that location as well. That would allow you to verify whether the cable and the port on the switch/router is good.

Another thing I'd try is using the following DNS servers -
198.6.1.1
198.6.1.2

These are UU.net's DNS servers and have never failed to be reliable. I've often seen where a sluggish DNS server will cause internet traffic to slow down. Tho it wouldn't explain why others with the same settings are fine.

Something else to check - make sure there aren't any proxy settings in the Network preferences.
 
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