dropping network connection

[mike]

I HAVE A PECULIAR PROBLEM,I HAVE TWO COMPUTERS SHARING A
BROADBAND CONNECTION THROUGH A MOTOROLA MODEM SB5100 AND
A BELKIN GATEWAY ROUTER F5D5230-4. ONE COMPUTER IS A DELL
DIMENSION L700CX RUNNING WINDOWS XP HOME WITH A LINKSYS
LAN CARD LNE100TX. THE OTHER IS A HOMEBUILT COMPUTER WITH
A SOYO K7V DRAGON PLUS M/B, (2) SEAGATE 40GB H/D'S
CONFIGURED AS INDEPENDENT DISKS (NOT RAID), RADEON 7500
AGP CARD, TDK CDRW, TOSHIBA DVD, SOUND BLASTER AUDIGY
SOUND CARD. HOME BUILT COMPUTER HAS BUILT IN LAN. I
DISABLED ON BOARD LAN AND INSTALLED A LINKSYS NIC CARD AS
PART OF TROUBLE SHOOTING. I DID THIS BECAUSE WE HAD A BIG
LIGHTNING STORM BEFORE MY PROBLEMS STARTED. THIS NETWORK
SET UP HAS PERFORMED FLAWLESSLY FOR OVER A YEAR. IN A
NUTSHELL MY PROBLEM IS THIS, THE DELL COMPUTER WILL
ACCESS THE NETWORK/INTERNET JUST FINE, THE HOME BUILT
COMPUTER WILL ACCESS EVERYTHING JUST FINE FOR ABOUT 2
MINUTES, AFTER LOADING A COUPLE OF WEB PAGES IT DROPS
OFFLINE. THE LOCAL AREA CONNECTION STATUS WILL SHOW ZERO
PACKETS SENT BUT WILL SHOW THAT THE CONNECTION IS ACTIVE
AND ENABLED. IF I REBOOT THE COMPUTER THE SAME SCENARIO
WILL OCCUR AGAIN. BOTH MODEM AND ROUTER SETUP PAGES WILL
SHOW THE DISCONNECT IF VIEWED FROM THE OTHER COMPUTER. I
HAVE TRIED UNINSTALLING & REINSTALLING EXPLORER, SYSTEM
RESTORE, PERFORMED TWO REPAIR INSTALLATIONS OF WINDOWS,
RESET THE TCP/IP STACK USING THE NETSHELL UTILITY,
CHECKED ALL CABLES/ CONNECTIONS, SWITCHED PORTS ON
ROUTER, ETC, ALL TO NO AVAIL. I THOUGHT ABOUT DOING A
CLEAN INSTALL OF XP, BUT I PREFER NOT TO AS I HAVE A LOT
OF CUSTOM SETTINGS AND PROGRAMS. I WOULD PREFER TO
ISOLATE THE PROBLEM AND FIX IT IF POSSIBLE.ANY COMMENTS
OR SUGGESTIONS WOULD BE MUCH APPRECIATED. POST HERE OR
FEEL FREE TO IM ME ON YAHOO, IDENTITY IS OLDSCHOOLROGUE
ON YAHOO MESSENGER.........THANK YOU



P.S. ONE OTHER THING WHEN IT GOES OFFLINE IT STILL SHOWS
A VALID IP ADDRESS AND DEFAULT GATEWAY UNDER STATUS. IT
ALSO WORKS PROPERLY IN SAFE MODE W/NETWORKING

 

[w_tom]

Don't start fixing things without first collecting facts. Mutliple
installs of what was probably a good OS install only multiples the
number of possible problems.

What did the system (event) logs say now and before they were
destroyed? What did the diagnostics, provided free by the computer
manufacturer, report? How did the various loopback tests perform?

Apparently you believe you suffered surge damage. The surge first
sets up a complete electrical circuit from some incoming utility,
through transistors, to earth ground. Apparently you believe that
surge path included the network wires. OK. What was in that path?
Which computers and or hub? This is how you also replace other
partially damaged peripherals before they cause intermittent failures
(and headaches).

Some things you must check if any surge got into the building.
Direct lightning strikes to incoming utilities don't damage
transistors IF the incoming utilities made a proper connection to
central earth ground. Where is the incoming broadband cable connected
to earth before it enters the building - essential to protect
transistors. That connection (that too many cable installer are not
taught) must be less than 10 foot to same central earth ground used by
AC electric and telephone. No earth ground means cable could have
been source of destructive surge. However most surge damage comes
from AC mains and is made easier if computer is plugged into an
adjacent surge protector. Incoming on AC mains. Next question is
what is the destructive outgoing path to earth.

BTW, stop yelling. Writing in all capitals is akin to yelling.

 

[Dave]

Hey two things.
If you do a repair does your internet connection come back
with out rebooting.
Second thing write down all your ip info and make that
computer static does it still drop

Oh did you try a differnet port on your router and or did
you upgrade the firmware

 

[mike]

Yes, I tried different ports on the router and updated
firmware. I even took the router out of the system and
connected the computer direct to the modem via cat5
cable, same thing happended. However, when I disconnected
the cat 5 and connected via USB everything works fine.
After doing this I then moved the NIC card to a different
PCI slot to get it on a different IRQ and reconnected via
cat 5 the problem then reappeared. Could this possibly be
a motherboard problem, maybe a bad PCI bridge?

 

[mike]

Sorry about YELLING, I didn't know that. I did much fact
finding before doing the repair installs. The ping,
netsh, and route commands all showed the same thing, a
good connection for 3 - 5 minutes and then the computer
was unable to communicate with the modem or router. I ran
net diagnostics and everything passed. My earth ground
for the coax is the same one used by AC power. One
interesting fact I've found is that if I remove the
router and just try to connect the one computer to the
internet I get the same results. Unless however i connect
the modem via USB. Using a USB connection the computer
functions fine. Could this indicate a motherboard problem
such as maybe a problem with the pci bridge?

 

[w_tom]

Diagnostics also (typically) have a loop back test where the port that
fails with continuous transmission will quickly fail. IOW is it the
hub or NIC? That testing in combination with swapping would quickly
identify the failed part. It sometimes helps to have a 'reversed'
ethernet cable so that two computers can be interconnected without the
hub. Cable can be built or bought in any computer store. But again,
the powerful part in a diagnostic is the loopback test that can find
hardware problems after so many bytes of continuous 'diagnostic' data.