Crossover cable

[MSL]

OK will the less complicated things are out of the way (have you checked/changed the cat5 cable?) Looks like some of the others who have more in depth talents than I will have to help from here on.

Caretaker: Yes. I have tried several different cat5 cables. I have went as far as checking continuity on them.

I would take a close look at the smaller PIC behind the MAGjack.  There were some issues with some of the pins not being properly soldered on some of the initial boards.  With light pressure and under magnification, drag a pin across the pins of the PIC.  If any of them move, then they are not soldered properly which could cause this issue.  It is also possible that the MAGjack itself is defective.

Tbone: I checked the small PIC. None of the pins move. There does appear to be a bridge between the two end pins in the lower right corner (see photo). Is that suppose to be there or should I attempt to remove it?

Thanks again to all who have helped.

Mark

[tbone321]

Yea, I believe that one is supposed to be there.  Was this EDT accidently connected to one of the hubs controller ports?

[MSL]

No. I just built this one. The only equipment it has been connected to is the PICkit 3 and an Express through a combiner (reversed).

[MSL]

And my laptop.

[MSL]

I just remembered the 49.9 ohm resistors that were replaced in one of the coops. I purchased this one from another member. He bought it from someone else. I don't know what coop it came from.

I tested the 4 resistors I installed and am reading around 0.3 ohm on each one.

Can someone look at the attached photo and confirm these are the wrong resistors?

If they are the wrong resistors did I do damage to the EtherDongle by using them?

Mark

[tbone321]

Those resistors are correct.  I'm not sure what you are saying here.  Were the 49K resistors there before? I would look into possibly replacing the MAGjack. 

[MSL]

Those resistors are correct.  I'm not sure what you are saying here.  Were the 49K resistors there before? I would look into possibly replacing the MAGjack.

What I am saying is I went back and tested all the resistors on the board. All the other resistors came within the allowed tolerances. Those four showed less then 1 ohm when I tested them. That is why I asked if they were correct. They are not testing as 49.9 ohm resistors. I am getting readings of .3, .2, .3 and .5 ohm respectively.

If those resistors failed would it cause the problems I am having?

I will purchase a MagJack. Do you know the Mouser part number for it?

[rmp2917]

Since those resistors are in parallel with the inductors inside the magjack, they will measure close to 0 ohms and will appear to be shorted when they are not. The only way to measure the resistors is to remove them from the board (or remove the magjack).

[tbone321]

It is not always valid to test a resistor in a circuit because you are also measuring the resistance of the circuit that they are a part of so the resistor is in parallel with other devices, you are also measuring the resistance across them as well and the measured resistance will always be lower than the lowest device in the parallel connection.  To get a true measurement of the resistor, you would have to remove one end from the circuit to break the link to other devices in the circuit.  There is a separate link to the MAGjack in the WIKI right under the BOM for the EDT.  It is a link to Newark, not Mouser.

[MSL]

It is not always valid to test a resistor in a circuit because you are also measuring the resistance of the circuit that they are a part of so the resistor is in parallel with other devices, you are also measuring the resistance across them as well and the measured resistance will always be lower than the lowest device in the parallel connection.  To get a true measurement of the resistor, you would have to remove one end from the circuit to break the link to other devices in the circuit. 

Thanks Tbone. I did not know that about testing the resistors.

I will order a MagJack and see were that leads me.

Mark

[Dennis Cherry]

Is the Green LED on the PCB on when you apply 6vdc power?

If not then the problem may be the 5.0 MHZ oscillator.

They will go bad or it is installed wrong.

[tbone321]

The picture he posted shows it installed correctly and he said that the green LED was lit after flashing the PIC.

[MSL]

Yes. The green LED on the board is on. No lights are on the MagJack.

Mark

[MSL]

Unfortunately I have another EtherDongle that I have not been able to program (another story / another time). When I power that one up the green light on the MagJack comes on. It appears that the MagJack on that EtherDongle is working. I de-soldered both MagJacks and swapped them. 

When I power up the one I have been working on (that now has a different MagJack) I still get no lights on the MagJack even if I plug it into the laptop (straight cable or crossover).

When I power up the other board (that I put the MagJack from this board on) the green light comes on the MagJack (like it did with the other MagJack before).

Anybody have any ideas (besides using this EtherDongle for target practice)?

Mark

[caretaker]

Ahh things are becoming clearer!  When you said the "green light" before I (and I think some others) assumed (I know you not supposed to do that!) that you were talking about the green led on the ether dongle board NOT the green led on the MagJack.  If the green light comes on on the MagJack then the MagJack is most likely working, it is just not receiving data. The green led on the EtD board also needs to be lit, this indicates the PIC is programmed. If the both Green LED's light then try this with your laptop, go into the setting for your network card and select the properties for the TCP/IP.  On that page if it says "Obtain an address automatically" uncheck that and enter "192.168.0.10" then save the settings. You will then need to reboot the computer. After that try the etherdongle with a regular (not crossed ) patch cord. If that is a no go, try the crossed connector. 
 

Unfortunately I have another EtherDongle that I have not been able to program (another story / another time). When I power that one up the green light on the MagJack comes on. It appears that the MagJack on that EtherDongle is working. I de-soldered both MagJacks and swapped them. 

When I power up the one I have been working on (that now has a different MagJack) I still get no lights on the MagJack even if I plug it into the laptop (straight cable or crossover).

When I power up the other board (that I put the MagJack from this board on) the green light comes on the MagJack (like it did with the other MagJack before).

Anybody have any ideas (besides using this EtherDongle for target practice)?

Mark