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Topic: Ethernet sheild(W5100) not working with Uno (Read 27653 times) previous topic - next topic

thebigzank

I did the 100 Ohm resistor trick, only I used 120 Ohm ones because that's what I had laying around.
It worked as advertised. :)
Whoever discovered (and shared) this first should be given a freakin medal!!!
I stumbled on to this thread just as I was on my way to throw away not one but fife "defective" W5100 shields.

On a side note, my W5100 shields don't join the ethernet on power up (all the com LED's remain off). They get online only once I press the reset button on the shield. I will now research this.

Mauriciopc92

Hello.  I signed up just to reply to this thread.  I purchased a few of these chinese W5100 boards and have been going nuts trying to get them running.  The resistor network is definitely the issue.

There are a few ways to re-work it without the 49ohm network.

I used 47ohm radial resistors and tried 2 different methods.  Both were successful.

Hopefully my pictures and notes help.

First method:

1. Remove the resistor network labeled 511 behind the RJ45 socket. I used a hotair station. Careful hand iron would work with some chipquick solder probably.
2. On the bottom solder shortened leads to pins 1,2,3,6. (Watch pin3, space the lead carefully)
3. combine the loose ends of 1,2 and then 3,4.  
4. Run hookup wire from the junction of 1,2 to the cap behind the rj45 socket, on the end closest to the socket.
5. Run hookup wire from junction of 3,4 to the cap to the right of the 102 resistor network, also to the side closest to the RJ45 socket.

Second method:
1. Remove the resistor network labeled 511 behind the RJ45 socket. I used a hotair station. Careful hand iron would work with some chipquick solder probably.
2. Fold 4x 47 ohm resistors so they are radially configured. Snip the leads about 3mm from the bottom of the resistor. Then tin the ends with solder
3. Installing the resistors in an alternating pattern(for space) you can tack them to the surface mount pads. I was able to tack one side at a time and then go back to add more solder, being careful not to bridge any pads.  **I found removing the RJ45 socket made this much easier**
4. The side of the pads away from the RJ45 socket are common to the capacitors, so you can double up and cross over the pads for each pair.  Meaning pad1 and 2 can share the opposite side and 3,4 respectively.

The first method seems to be the easiest using 1/4w resistors.  I have some 47ohm surface mount resistors at work that I may try, but with what I had at home, this worked quite well.

Here are some images of the re-work.  I tested using the Webserver sample code and it worked immediately.

Link to Imgur gallery (images are larger than 1mb)  http://imgur.com/a/JrPFD


Hope this helps!




Hello Rostit,

I made the first method and worked perfectly! It was hard to find 4 470ohm resistors here...haha
So I soldered on the bottom of the shield, 'cause it seemed to be easier and safer.
I recommend everyone to do this way!

I hope you all can do it!

Rostit, thank you so much for your help!

emaema

Hello and first of all, scuse me for my bad english.

Just for my bad english, i am not able to understand your explanation, and so, i need some help....

Well, first step, is totally removing 511, is it ok? Or can i only disconnect some pins?

Second step:
If i totally remove 511, i have so 8 free pins. I need to connect pins 1 and 2 via 47ohm resistor and pin 3 and 6 via 47ohm resistor. Is it correct?

And the other pins? Must i leave them free?


Thank you very much for your response and please, scuse me very much for my bad english.....


Ema from Italy.

zakrzew

[...]
Well, first step, is totally removing 511, is it ok? Or can i only disconnect some pins?

Second step:
If i totally remove 511, i have so 8 free pins. I need to connect pins 1 and 2 via 47ohm resistor and pin 3 and 6 via 47ohm resistor. Is it correct?

And the other pins? Must i leave them free?

[...]

Ema from Italy.
Hi,

Actually removing existing resistors is not necessary. You can use method described by k1ggi on Dec 28, 2015, 05:16 am. Soldering 100ohm resistors between 1 and 2, and then 3 and 6 is enough.

Tested with positive effect :)

Greetings,
Tomek

antoniodv

I have the same problem.
Thank you for your advice.
Antonio de Vincentiis

antoniodv

#50
Mar 11, 2018, 01:12 am Last Edit: Mar 11, 2018, 01:32 am by antoniodv
I have only 100 ohm SMD resistors. I found this solution by slightly folding the pins 3-6




yuksel19

#51
Jul 20, 2018, 12:42 pm Last Edit: Jul 23, 2018, 03:49 pm by yuksel19
W5100 ethernet shield power on reset solution

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