WRT54G - unable to communicate

192.168.0.1 is the IP address of the router. Use that to configure the router via the browser.
            ^

try removing power from the unit , hold in the reset, apply power, after 20 seconds or so let out the rest button, then connect one w/s with a cat5 streight through cable to the router nothing else, open a comand prompt ,,, do the ipconfig /all ,,, release .... renew . Then in the browser type in th 192.168.xxx.xxx that gets you to the devices embeded web page.

Actually according to the manual 192.168.1.1 is the default.
Sometimes if the units become locked up you have to reinstall or upgrade the firmware. Since you cannot log on to do so there is Linksys has a free TFTP software application you can download and use to try to re-load.  Very simple and works well. It is available from:
  ftp://ftp.Linksys.com/pub/network/tftp.exe 
It comes with .pdf file instructions.
You will also need the latest firmware version for your router. Go to the following site and follow the links for your router. There are several versions, so make sure you match the version # of your WRT54G:
http://www.linksys.com/servlet/Satellite?c=L_Content_C1&childpagename=US%2FLayout&cid=1115416835852&pagename=Linksys%2FCommon%2FVisitorWrapper

Is this a wireless router and are you doing this from a wireless workstation?

If you disabled the DHCP server, what is assigning your IP address?  Your computers IP address must be in the same IP subnet as the WRT54G, which by default is 192.168.1.0/24 (netmask of 255.255.255.0).

Hard code your IP adress to 192.168.1.2 mask 255.255.255.0 and see what happens.

Thanks for all who have given hints so far.

To clarify the configuration, the router is connected to the computer's network port via CAT5. I have to assume that the cable is configured correctly because It is the same cable that I pulled out of my main router, through which I am posting this message.

I tried to restore the factory default by removing power, holding the reset button in, restoring power and continuing to hold it in for over 20 seconds. No response to ping or browser.

I have tried to "hard code" the router address by specifying the ip address to use in the Local Area Connection properties rather than allowing the computer to obtain a IP automatically. I have tried both 192.168.0.2 and 192.168.1.2 and attempted to ping 192.168.0.1 and 192.168.1.1 respectively. Ping just times out.

I downloaded tftp; I found no documentation.  I ran it and it puts up a screen requiring server, password and file. From what I can gather elsewhere on the web, server is the identification of the routher. Since there is no IP address that I can find, I'm stuck.

The WRT54G is a wireless router with 4 CAT5 connections as well as an internet connection. I have been connecting to the cat5 ports via cable.

I am still looking for a solution. thanks to all who have posted already.

Is the power light blinking?

When the WRT54G is powered up and your PC is connected is the port light on for the port you are connected to?

You may want to try this:

http://linksys.custhelp.com/cgi-bin/linksys.cfg/php/enduser/std_adp.php?p_faqid=175&p_created=1084205858&p_sid=bahDSq*h&p_accessibility=0&p_lva=&p_sp=cF9zcmNoPTEmcF9zb3J0X2J5PSZwX2dyaWRzb3J0PSZwX3Jvd19jbnQ9MTAmcF9wcm9kcz0wJnBfY2F0cz0mcF9wdj0mcF9jdj0mcF9zZWFyY2hfdHlwZT1hbnN3ZXJzLnNlYXJjaF9ubCZwX3NjZl9sYW5nPTEmcF9wYWdlPTEmcF9zZWFyY2hfdGV4dD1jYW4ndCBwaW5n&p_li=&p_topview=1

Disabling the DHCP service should not have that effect, sounds like a bad firmware image.  Make sure your ip, subnet and gateway are set correctly. If you can not push the firmware though tftp then you might have to exchange the product.

Hope this helps.

Thanks again for all the help.

I've run the ipscan program for 192.168.0.1->192.168.9.?? and found no active IP addresses other than the computer itself. I also ran it in the 127.0.0.0 range and of course if found local host. I have not run it for the entire range of ip addreses (0.0.0.0->255.255.255.255). That will take some time and I'm not sure if it is even necessary.

Thanks for the "How to Upgrade Firmware doc, RobWill. I'll read it in the am.

I did learn that the WRT54G router is currently functioning as a switch and if a computer is connected to one of the WRT54G lan ports and another WRT54G lan port is connected to a lan port on a second router with DHCP functioning, the computer is assigned an Ip from the second router and can communicate through both routers to the internet. I still have no idea how to find the ip of the router.

Thanks again and good night.

on one of the pc go to the command prompt and run "tracert [ip address of another computer]" and see if it lists the hops through the router

If you want to run the IP scan it is unlikely it would be other than 192.168.x.x  You should be able to set the computers subnet mask to 255.255.0.0 and scan 192.168.0.1 to 192.168.254.254 to cover all likely possibilities.

Don't assume it is something you have done. I have set up over 75 routers and sent back 6. Some do fail. Run all possible tests and then simply ask to return. If you provide a credit card they will "cross-ship", sending you one right away.

have you taken a look at the forums on http://www.linksysinfo.org/ its pretty much a site devoted to the wrt54g. you will also find some repair guides which are not ip dependant i believe

McAfee identifies ipscan as a "potentially unwanted program" and has decided not to let me run it today. I'm sure that I can get around this but do we know that ipscan is truly a safe program??

With my computer connected to a lan port of the WRT54G and another lan port of the WRT54G connected to my active router, I tried tracert. NO other routers are identified.

I have posted with linksysinfo, however, the dialog here has been much more active. Thanks again.

There are lots of other IP scanners out there if you want to try but I am doubtful it would be set to other than your previous configuration or the default. IPScan should be save, but any scanner can be considered "unwanted" as they are primarily used as a first step in hacking"

A couple of options for scanners:
Very small file scanner TCPViewer;
http://www3.ns.sympatico.ca/malagash/Downloads/TCPNetView/TCPNV.EXE
TuCows options;
http://www.tucows.com/search?search_terms=ip+scanner&search_scope=win&search_adv=0&search_size=&search_size_multi=b

Mcafee with show ipscan as an unsafe program due tot he port scanning nature of the program but it is a safe program for this use. i thought tracert tracked the path of a ping through router but it doesn't seem to do this on internal lans. I do not know of another method of tracing a ping but i am sure there is one. i saw a couple of posts on the linksys forums about router not resetting properly and that seems to be what is happening here. Any chance of disconnecting the router power for like 24 hours and trying to reset it again then?

tracert (traceroute) does trace the path of a packet through routers.  However, when you have to computers on the same subnet they do not go through a router, thus tracert does not show anything.  Most home devices these days are routers and switches combined in one device.  The WRT54G is one such device.  The traffic between the switch ports and wireless devices are switched, not routed, thus tracert will show nothing.  All traffic between the WAN port and everything else is routed so tracert will show you that you are going through a router.

so is there a way/program to see all the connections. I have been looking here http://www.netpenguin.net/download.htm which seems to suggest it is a program that will show all connections made to the pc including the router but i haven;t had chance to use it yet

To all those who posted suggestions, thanks. I have run the Angry IPSCAN throughout the range 192.168.0.0->192.168.254.254. Other than the computer, there were no active ports. I am now trying to get answers from Linksys. They don't respond nearly as quickly as Experts. I'll post results when I find out what they are. Thanks again

It sounds like the router was hosed somehow and may need to be replaced.  This did not occur because if disabeling DHCP.  I have DHCP disabled on mine, by is a GS though.  

Time is money, I think at this point you should contact Linksys and request a return RMA:
https://ssl.linksys.com/rma1.asp

Rob did you ever get chace to disconnect it from the power for a day or so and then try a hard reset?

sorry, that comment was directed at jwmarkert

The router was disconnected for about 6 months from the time the problem first manifested itself until a few days ago when I started working on it again.

"Disconnected" from what?  Could it have been connected to a power source and fried by a power surge?

I'v increased points to recognize diagnostic help that led me conclusion that router was NG. Thanks to all.

Thanks  jwmarkert,
--Rob