no network activity leds

[Steve Gase]

I have 2 EtDs that were built by someone else but not working.  I have 2 more EtDs that I just built.
After loading pixelnet firmware into all four I started with my first test... connecting power, then ethernet.

3 of the 4 units are fine so far... i'm stopping for the night.
the 3 have a green led on the board, and when connected to my ethernet swith I get ethernet activities lights -- solid green and flashing yellow.

the 4th unit looks broken.  with power I get the green led on fine.  BUT the is no activity on the ethernet connector.

solder points look good to me.  chips appear to be oriented correctly.  i don't see any bridging -- even on the surface mount chips.  when i burned  the firmware i also did a verifiy (as always) and it had no problems.

Any idea on what next to try?  (i'm thinking of swapping swapping socketed chips with a working unit next.)

[tbone321]

Now you have been here long enough to know that good closup pictures are required to assist in diagnosis and to help rule out the simple things.

[caretaker]

According to RJ "It is not a power indicator. It is connected to the ethernet phy chip. It is an indicator for it." I had a hard time getting my ED to work check out this post for some things to try:  You are not allowed to view links. Register or Login   Common problems, bad Xtal's (post has procedure for checking), solder bridge on ethernet chip (I looked five or six times and did not see one but when I went around the chip with flux and desolder braid it fixed the problem). 

[Steve Gase]

It was late at night, so I thought I'd post the question before the pics.
I swapped out socketed chips and the questionable chips worked in another board, and good chips did not work in the questionable board.
I checked all of the soldering and could not find anything -- touchups did not work.

I finally used a magnifying glass and found what I think to be the problem...  a missed leg on the small surface mount chip -- pin #1 and I can't read any descriptive text on the chip. 

can someone confirm that this particular problem would cause the described behavior?

next... what do people do when we get a bad surface mount?  is this problem even repairable?  do I buy a new kit?  do coop managers plan for failures and have a few replacements in reserve?

thanks.


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[RJ]

Unless I am nuts that is not a broke leg you have all 12 on that side it is a rouge piece of material that should not be there.

There is 12 legs on each side of that chip.

Am I correct?

RJ

[Steve Gase]

 

it looked so realistic! i used tweezers and it came out and blew away. 

so... back to an unexplained issue.

here is the front and back-sides of the board.

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I didn't solder this one, and I've wondered of the tinge of black -- is it from an iron that is too hot? or a different kind of solder?

[chrisatpsu]

is there a solder bridge on the long dual row of pins?

about 8 or 9 pins down on the outside?

[n1ist]

On the back side, near the magjack, there are a number of solder joints that don't look like they have flowed correctly; I still see the gold plating on the pads.  Try reflowing them and see if it helps.
/mike

[Steve Gase]

is there a solder bridge on the long dual row of pins?

about 8 or 9 pins down on the outside?

  no bridges.  but there was some of that blackened residue.  it cleaned it up and also did the same for each of the other tight spots.

still broken.

[RJ]

I hope the black is not from someone using plumbers solder. I had a dongle sent to me like that once years ago and I had to remove all solder clean and resolder the board to get it working. It had black goo of a flux not like normal rosin. I do not know that was what is was but they jonits also were grainy. Almost lilke no lead solder but with black goo on it.

RJ

[rm357]

I'm thinking that your iron is not hot enough. Many of your solder joints have not flowed through the board. I usually use too much solder which makes little balls on the other side of the board, but I know I've got a good connection when both sides of the board look like they've be soldered.

[Steve Gase]

I hope the black is not from someone using plumbers solder. I had a dongle sent to me like that once years ago and I had to remove all solder clean and resolder the board to get it working. It had black goo of a flux not like normal rosin. I do not know that was what is was but they jonits also were grainy. Almost lilke no lead solder but with black goo on it.

RJ

My helper used good solder.

I got the solder at Altex.
It say's Core Solder.
Sn60Pb40
RA300
3.3%fux

[Steve Gase]

I'm going to do the following tonight:

• get better light and magnifying glass
• use flux and braid to do thorough check around the SMT chips
• reflow all of the connections --  add more solder with sufficient heat to get it to come through to the other side of the board
• clean up solder spatter
• check voltages:
  
  • crystal voltages (Xtal should read 3.3 volts between pins 4 and 8 and 1.6 volts (approx) between pins 4 and 5 )
  • 5V regulator (7805): 7.98V on pin 1, 0V on pin 2 and 5.00V on pin 3
  • 3.3V regulator (117v33): 0V on pin 1, 3.29V on pin 2 and 5.00V on pin 3

If I'm not successful, then I'd next like to have some info on other meter readings -- which specific locations to test, and what readings to expect.  Hopefully someone can share the technical details. 

These threads have been excellent for information... can links to each be added to the wiki us "Troubleshooting Discussions"?
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Thanks!

[rrowan]

I'm going to do the following tonight:

• get better light and magnifying glass
• use flux and braid to do thorough check around the SMT chips
• reflow all of the connections --  add more solder with sufficient heat to get it to come through to the other side of the board
• clean up solder spatter
• check voltages:
  
  • crystal voltages (Xtal should read 3.3 volts between pins 4 and 8 and 1.6 volts (approx) between pins 4 and 5 )
  • 5V regulator (7805): 7.98V on pin 1, 0V on pin 2 and 5.00V on pin 3
  • 3.3V regulator (117v33): 0V on pin 1, 3.29V on pin 2 and 5.00V on pin 3

If I'm not successful, then I'd next like to have some info on other meter readings -- which specific locations to test, and what readings to expect.  Hopefully someone can share the technical details. 

These threads have been excellent for information... can links to each be added to the wiki us "Troubleshooting Discussions"?
You are not allowed to view links. Register or Login
You are not allowed to view links. Register or Login

Thanks!

Hi Steve,

I hope you find the problem. If not then maybe RJ can give you more info for meter readings.

As far at the Wiki, Sure it can be added but to be honest links back to the forum in the wiki for troubleshooting is not a good option. Putting the text info in the wiki that is in those links work much better.

Rick R.

[Steve Gase]

• get better light and magnifying glass
• use flux and braid to do thorough check around the SMT chips
• reflow all of the connections --  add more solder with sufficient heat to get it to come through to the other side of the board
• clean up solder spatter
• check voltages:
  
  • crystal voltages (Xtal should read 3.3 volts between pins 4 and 8 and 1.6 volts (approx) between pins 4 and 5 )
  • 5V regulator (7805): 7.98V on pin 1, 0V on pin 2 and 5.00V on pin 3
  • 3.3V regulator (117v33): 0V on pin 1, 3.29V on pin 2 and 5.00V on pin 3

 

There did seem to be some bridging on the PIC.  I used flux and then the solder sucker and it now looks good.
I tested the regulator and 50 xtal voltages described above -- and they are good.

So, I've run out of ideas.  it still doesn't work.

To summarize -- I have 3 units that show life on the magjack, but unit #4 does not.
I know that the cable is good (because of the success of units 1-3).
The power LED on units 1-4 ALL come on.
voltages on 50 xtal, and each regulator all match the numbers aboe.

Other tests to try out?