Ethernet connection problems

My house came prewired with Cat5 connections in every room, so I currently have a setup of WDTV players in each room to stream content from my PC.
However, in my son's room there seems to be a problem with the connection.
The WDTV player will not connect to the network via wired Cat5, only wireless.
I tried another unit from another room and get the same problem.
Each time I get a message stating it cannot get an IP address.
The green and yellow lights are flashing in the back of the port on the WDTV player, so there seems to be a connection going.
I tried another ethernet cable and got the same thing.
I moved the unit to another room and it works via Cat5 connection.
What could the problem be?

I would first confirm that the port is working by plugging a laptop in to the port and attempting to stream from a laptop.

Quote from wwhsgrad2002 : I would first confirm that the port is working by plugging a laptop in to the port and attempting to stream from a laptop.

Just tried and I cannot connect via wired. I can only connect via wireless.
I get a message stating that the ethernet cable is not plugged in, even though it is.

Ethernet is a star topology. Both ends of the cable have to be connected to something and they meet in a central location where multiple cables are connected to an ethernet switch.

Find the other end of the cable the goes to your son's room and verify if it's connected to anything. If it is connected, try different patch cables on both ends (short cables that go from jack to device or switch) and try a different port on the switch. If the other end of the cable isn't connected to anything, connect it to a switch.

The other end of the cable goes to my router. I tried switching to another port on the router but get the same problem. The connectivity light is flashing on my router for that port.

How is the end of the cable that goes to your router terminated? Does it have a modular plug and goes directly to your router? Does it go to a patch panel or wall jack and then is there a patch cable (short ethernet cable) from there to your router? A photo of this area and of the jack in your son's room after unscrewing it from the wall an pulling it out a couple inches would go a long way.

If you have a relatively new computer, check to see if the network adapter drivers have a tool to test the cable (see screenshots). If not, try updating your network drivers or look in your bios to see if a similar tool exists. Run these tests on the cable from both ends with the patch cable still connected to the jack in the bedroom when you test the other end. Scroll though all the results and describe what it says or post screenshots. Your computer my have a tool like this with slightly different steps needed to get to it, poke around.

Sounds like a bad run. Cable is damaged or broke somewhere along the line. Either wall fish a nre run yourself, or have someone come out

Quote from TheSawg : Sounds like a bad run. Cable is damaged or broke somewhere along the line. Either wall fish a nre run yourself, or have someone come out

Quite possibly, but the problem is likely near one of the ends of the cable. If you can do a test like I suggested, you can get a lot more information.

Take the jack off the wall too, you might find they didn't even terminate the cable. Pictures are worth a thousand words.

If the house has wired cat5 jacks, it's possible the owner took out the original patch panel that connected to the router.

Sounds like the wiring in the wall is messed up, I would take off the plate on both ends and make sure that the wire is secure in the panel and there is no issue on the rj45 (the plug it's self) for the wire running though the wall. By the lights lighting up we know that the router sees something plugged in but it does not mean that one of the wires in the cat5 cable is not damaged or you are getting interference from from something like a power line.

As other have said you are better off doing your testing with your laptop then the WDTV as it gives you more control.

I would plug in a laptop into the router with a short ethernet cable directly and make sure the laptop gets the IP info (by renewing the IP or reboot) before start troubleshooting the wiring in the walls.

Here are some pictures of my setup. I apologize if the quality is poor.
The first couple of pictures are the connections in my son's room.
The last few pictures are where all the Ethernet cables from the different rooms in the house meet (after passing through the attic) to go to my Linksys E3000 router.

Looking at that structured media cabinet makes my eyes bleed a little. I don't like to see that much of the cable without its jacket at the punch down jacks but at least it looks like they kept the wires somewhat twisted.

Were the yellow Cat-5 intended for phone originally and the blue for data? The upper module in the cabinet is supposed to be a patch panel for data and cable. The lower module is an amplified splitter (with limited bandwidth thus it's unused) and telephone distribution module.

Macro mode can help you take close up photos that are in focus, but may not be an option on cell phone cameras.

Look closely at the keystone jack, there should be two color codes shown possibly with numbers 1-8 the two sets of colors be be denoted A and B or T568A/B. Verify that the colors of the wires matches one of the color codes on the sticker and tell us which one, preferably tell us which color wires correspond to each number 1-8. Look closely at the other end of the cable, try to visually verify that all of the wires were fully inserted into the modular plug and with the tab down provide us with the colors of the wires from left to right (probably Orange-white, Orange, Blue-white, Green, Green-white, Blue, Brown-white, Brown).

Do any of your computers have a cable test utility in the drivers like I showed earlier? If not have you checked for driver updates or looked to see if a similar tool exists in any of your computer's bios? These tools work surprisingly well and can often pinpoint to location of the failure in a cable within a couple feet.

Quote from jkee : Looking at that structured media cabinet makes my eyes bleed a little. I don't like to see that much of the cable without its jacket at the punch down jacks but at least it looks like they kept the wires somewhat twisted. Were the yellow Cat-5 intended for phone originally and the blue for data? The upper module in the cabinet is supposed to be a patch panel for data and cable. The lower module is an amplified splitter (with limited bandwidth thus it's unused) and telephone distribution module. Macro mode can help you take close up photos that are in focus, but may not be an option on cell phone cameras. Look closely at the keystone jack, there should be two color codes shown possibly with numbers 1-8 the two sets of colors be be denoted A and B or T568A/B. Verify that the colors of the wires matches one of the color codes on the sticker and tell us which one, preferably tell us which color wires correspond to each number 1-8. Look closely at the other end of the cable, try to visually verify that all of the wires were fully inserted into the modular plug and with the tab down provide us with the colors of the wires from left to right (probably Orange-white, Orange, Blue-white, Green, Green-white, Blue, Brown-white, Brown). Do any of your computers have a cable test utility in the drivers like I showed earlier? If not have you checked for driver updates or looked to see if a similar tool exists in any of your computer's bios? These tools work surprisingly well and can often pinpoint to location of the failure in a cable within a couple feet.

It seems now I can't even get a connection to test the cable.
It's been hit or miss all day.
Sometimes the light on the router will come on and sometimes it won't.
No lights flashing on the device port either.

A lot of the wiring you see is for the home alarm system and phone jacks. It was all pre-wired by the builders.
I'm not sure if blue the cables were intended for one thing and yellow for another.
They both seem to work just the same.