W. eWatson said:
Well, this turned out to be a simple problem. I figured it had to do
with the PC, so I put an XP laptop on the cable. The light stopped
blinking. BTW, it's a slow blink. Once per second or two. However, I
couldn't see the other PCs on the LAN, so I looked closer on the back of
the (desktop) PC, which is in a difficult to see the back. I found I had
a built-in ethernet port and two on an internet card. I found that on
the troublesome PC port that pushing hard apparently did the trick. All
seems well now.
I had a buddy that was trying to fix non-working video in his home PC
for a month. He and I worked in the Software QA group and were used to
building and fixing our own alpha lab test hosts. He even replaced the
motherboard thinking a cracked slot housing was the problem. He
eventually brought it into work where he was going to start swapping out
parts with our alpha lab hosts. Whoa! Don't be farking with our
company gear. So I decided to look into what was his problem. This had
an AGP video card. I pulled the card out and pushed it back in. His PC
worked. He wondered what magic I had performed. I smiled at him and
said that he had not pushed the card all the way down into the slot. He
had pushed just far enough to start insert of the card but more effort
was needed to get the slot pins to move aside to shove the card between
them. He had worked on this for a month, replaced the mobo, tried
another AGP video card at work, swapped out memory, and who knows what
(it's been a long time since this happened). After that, all I had to
do was smirk at him and he'd retort "Shut up". He knew what I was
smirking about.
Besides a port that requires a bit more oomph to push in the connector,
also watch out for connectors that are missing the locking tab. It's
the plastic finger sticking out from the side of the connector. If
gone, there's nothing to keep the connector in the port. When pulling
cables through the walls, ceilings, or under the raised floor, we put
tape around it so the locking finger doesn't get pulled off. Some RJ-45
connectors have a shroud around them to protect the end of the finger
but I find them more difficult to push against to press down the finger
to remove the connector.
So it was a bad cable - in that it didn't get fully seated. Glad it was
an easy and cheap fix. I'd be checking why it was so hard to push in
but if it's working then leave it be. The port connector has solid
wires or pins that angle into the opening. If you look inside the port
connection, it looks like
http://ak.buy.com/PI/0/1000/231526217.jpg.
The connector you slide in has finger contacts that wipe against the
pins which spring outward as you slide the connector into the port. If
a pin is bent sideways, it could be trying to slide atop the plastic
spacer between the finger contacts on the connector. Besides getting
bent out of alignment, I've also seen where the pins get bent up.
Because they don't extend down as far means less spring pressure of the
pin against the finger. The sliding action of pin against finger wipes
the contacts on each but there has to be some pressure for the wiping to
work and to ensure the pin is against the finger. In some cases, mostly
due to abuse, I've had to pull the pin inward to the center of the hole
so it would make contact and provide some pressure when the connector
was inserted. A few times I've had to pull them to the side because
they were misaligned.
There is always a chance that the connector on the end of the RJ45 cable
is defective. The wires are crimped onto pinching fingers. The fingers
pinch the wire to pierce through the insulation to make contact with the
wire. See
http://www.jebcable.com/upload/product/big/1241746785.jpg
which shows the contact fingers on the left side of the connector.
Notice they are like blades that extend into the connector. You push in
the individual wires, press down the blades, and the blades pinch the
wires to get through their insulation to contact the metal wire inside..
Sometimes the blades don't make good contact or the connection gets
abused (by users pulling on the cable instead of the connector). It is
not a solid permanent connection of the wires inside the connector. The
wires are not soldered to the contact fingers in the connector. It's
just a pinched connection. Pushing hard (in or out) on the cable can
move the wires around enough to make break the connection and then doing
the same can temporarily "fix" the connection but later movement or
stress on the cable can result in a bad connection again. Wiggle the
cable around to see if you lose the connection. Stress it by flexing it
constantly in one direction and repeating in other directions.
See
. At step 4 (1:48
timemark), see how the wires are slid inside the connector. You can see
the fingers on the left side of the connector. The crimper presses
these into the connector so their piercing fingers pinch through the
insulation to contact the wires. The piercing isn't always perfect and
a pinched connection isn't the best for durability or reliability. The
pinched connection is similar to how a Scotchlok crimp connector works
(
).
If it took a lot of pressure to push in the RJ45 connector into the port
then something is probably wrong. Could be a bent pin inside the port
connector. Could be the locking finger on the connector is broke or
twisted. Could be a protective shroud around the connector (mostly to
protect the locking finger) is too far forward so you end up having to
push harder because you're having to push back the shroud as you're
trying to shove the connector in the hole.
I did run into more trouble when I hooked up a Win7 PC laptop. I could
get a Login dialog to the other PCs, but couldn't sign-in. I'll
worry about that another day.
Don't use homegroups in Win7. Only Win7 editions know about homegroups.
No prior version of Windows support homegroups. Use workgroups on the
Win7 hosts.
