Wiznet W5100 Repair Info -Cheap Board

I posted this at the end of a thread but figured it may help others looking to figure out why brand new W5100 shields are not responding. Here are the steps I used to repair them. With better parts and tools there are better ways to do it, but this worked and got me up and running with what was in the house. Hope this helps some people!

I purchased a few of these Chinese W5100 boards(eBay) 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 tested using the Webserver sample code and it worked immediately.

Here are some images of the re-work. Link to Imgur gallery (images are larger than 1mb) http://imgur.com/a/JrPFD

Good Luck!

Thanks.

ADDED:
I read the other posts. It seems that many of the cheap ethernet shields have a resistor network with the text "510", that is 51 ohm, and is close enough. However, probably due to a mistake, a number of shields have the resistor network with the text "511", which is 510 ohm. That will not work.

The original Arduino Ethernet shield uses a resistor network of 49R9.

If a cheap clone with W5100 chip is bought, at least buy a 'R3' version. If you have the wrong resistor network, try to get your money back.
I have added a heatsink to the W5100 because it gets hot. Therefor I prefer a W5200 or W5500 chip.

This post should be pinned to the top of the networking forum ... so common is this issue. There is another option ... remove and replace the resistor network with something around 49.9 ohms. Its tricky but it can be done.

keithsw1111:
This post should be pinned to the top of the networking forum ... so common is this issue. There is another option ... remove and replace the resistor network with something around 49.9 ohms. Its tricky but it can be done.

I don't think this problem is a common issue. Best plan is to buy based on the reputation of the vendor and not necessarily lowest price. The below vendor is not the cheapest by about $2, but has sold a lot of shields and has a good customer rating. Always check the vendor negative ratings to see if any are based on the product you are buying.

Koepel:
Thanks.

ADDED:
I read the other posts. It seems that many of the cheap ethernet shields have a resistor network with the text "510", that is 51 ohm, and is close enough. However, probably due to a mistake, a number of shields have the resistor network with the text "511", which is 510 ohm. That will not work.

The original Arduino Ethernet shield uses a resistor network of 49R9.

If a cheap clone with W5100 chip is bought, at least buy a 'R3' version. If you have the wrong resistor network, try to get your money back.
I have added a heatsink to the W5100 because it gets hot. Therefor I prefer a W5200 or W5500 chip.

The cost to return the boards outweighed the cost of using some resistors I had laying around. The 50 ohm will work as the total termination resistance should be 100ohm for ethernet. Using 47ohm radial resistors works just fine. I tested up to 100ft of ethernet cable and it was stable. For termination you can have a little lee-way in the resistor values.

zoomkat:
I don't think this problem is a common issue. Best plan is to buy based on the reputation of the vendor and not necessarily lowest price. The below vendor is not the cheapest by about $2, but has sold a lot of shields and has a good customer rating. Always check the vendor negative ratings to see if any are based on the product you are buying.

http://www.ebay.com/itm/Ethernet-Shield-W5100-For-Arduino-Main-Board-2009-UNO-ATMega-328-1280-MEGA2560-/400356634583?hash=item5d371d6fd7:g:EB0AAMXQBg5Rrcx~

I paid less than $2 a piece including shipping. For that price I have no problem replacing the resistor network now that I know they work fine otherwise. I have already ordered more, but this time I ordered some SMC 510 networks to replace the 511. 3 for the price of one of those is worth it to me. This isnt for everyone of course and if you are not handy then by all means buy the one that has no issues.

I bought mine from an USA seller. $7.99 including shipping, but he sold out. :slight_smile: