This is the Lantronix Xport module.

http://www.lantronix.com/device-netw...ers/xport.html

This particuler unit randomly, a couple of times a week maybe, draws a
lot of power and gets very hot, 80C or so, and still works, but
flakily. So we decided to rip it open and see what's inside.

I love those LEDs.

The two chips are a Lantronix thing and an Atmel serial flash. So
there must be a heap of ram inside the Lantronix chip, enough for the
tcp/ip stack and the jvm and all that.

I scaled the pic res down, as the original files were huge.

John

"John Larkin" wrote in message
...
This is the Lantronix Xport module.


http://www.lantronix.com/device-netw...vers/xport.htm
l

This particuler unit randomly, a couple of times a week maybe, draws a
lot of power and gets very hot, 80C or so, and still works, but
flakily. So we decided to rip it open and see what's inside.

I love those LEDs.

At least one looks to be bi - color as it looks like there are two bond
wires and two LED dies in it.

There seems to be significant manual assembly needed for these, as it would
be hard for a robot /selective solder to solder many of the through hole
components (LEDs, inline header, ground wire, connector going to the outside
for your PCB, RJ45 pins (they are SMT on both sides of the board), the
transformer wires (these may be wave or selective soldered)). The manually
assembled parts look to have significant weird looking flux residue around
them, at least on the blue board.

Weird ground wire (I assume) going to the rear case.

I am quite surprised they used a 1.6 mm thick PCB, and one close to it. I
suppose they have the room (there is surprisingly a lot of room left over).
The simple top PCB is at least a 4 layer PCB.

It's weird they used a custom set of pulse transformers and potted them to
the PCB. They must have had problems finding one small enough, but then
again the ones in PCMCIA cards were quite small.

I'm surprised the Atmel memory IC is a BGA - all the ones I've currently
used and seen were CASON 8 or oversized body SO8's

There are a bunch of 0402's. The pads width and overall length looks good,
but the gap between the two pads looks a little large - possible tombstone
or worse, drawbridge problems, but without having the actual dimensions or
looking at the board in more detail, it's hard to say.

There is no evidence of something getting hot - usually the PCB will darken
in high heat areas, and if really hot, the solder joints will melt a bit,
giving a cold solder / wrinkly look to them


The two chips are a Lantronix thing and an Atmel serial flash. So
there must be a heap of ram inside the Lantronix chip, enough for the
tcp/ip stack and the jvm and all that.

I scaled the pic res down, as the original files were huge.

John

On Sat, 05 May 2007 15:51:59 GMT, "Jeff L"
wrote:


"John Larkin" wrote in message
.. .
This is the Lantronix Xport module.


http://www.lantronix.com/device-netw...vers/xport.htm
l

This particuler unit randomly, a couple of times a week maybe, draws a
lot of power and gets very hot, 80C or so, and still works, but
flakily. So we decided to rip it open and see what's inside.

I love those LEDs.

At least one looks to be bi - color as it looks like there are two bond
wires and two LED dies in it.

There seems to be significant manual assembly needed for these, as it would
be hard for a robot /selective solder to solder many of the through hole
components (LEDs, inline header, ground wire, connector going to the outside
for your PCB, RJ45 pins (they are SMT on both sides of the board), the
transformer wires (these may be wave or selective soldered)).

Yeah. The board-board pins are stiff, old cordwood style. Must be hell
to rework.

The manually
assembled parts look to have significant weird looking flux residue around
them, at least on the blue board.

Ugly yellow no-clean flux everywhere.



Weird ground wire (I assume) going to the rear case.

Right.


I am quite surprised they used a 1.6 mm thick PCB, and one close to it. I
suppose they have the room (there is surprisingly a lot of room left over).
The simple top PCB is at least a 4 layer PCB.

It's weird they used a custom set of pulse transformers and potted them to
the PCB. They must have had problems finding one small enough, but then
again the ones in PCMCIA cards were quite small.

I'm surprised the Atmel memory IC is a BGA - all the ones I've currently
used and seen were CASON 8 or oversized body SO8's

Balls on the top ic are directly opposite balls on the other one.
Ballsy, somebody called it.


There are a bunch of 0402's. The pads width and overall length looks good,
but the gap between the two pads looks a little large - possible tombstone
or worse, drawbridge problems, but without having the actual dimensions or
looking at the board in more detail, it's hard to say.

There is no evidence of something getting hot - usually the PCB will darken
in high heat areas, and if really hot, the solder joints will melt a bit,
giving a cold solder / wrinkly look to them

Every once in a while, Icc would jump up and the case would go up to
80C or so. It still worked, mostly. It would take a power cycle to
reset it. Sure sounds like cmos latchup to me. Standard factory
reaction, "that's never happened before."

John

"John Larkin" wrote in message
...
On Sat, 05 May 2007 15:51:59 GMT, "Jeff L"
wrote:


"John Larkin" wrote in
message
.. .
This is the Lantronix Xport module.



http://www.lantronix.com/device-netw...rvers/xport.ht
m
l

This particuler unit randomly, a couple of times a week maybe, draws a
lot of power and gets very hot, 80C or so, and still works, but
flakily. So we decided to rip it open and see what's inside.

I love those LEDs.

At least one looks to be bi - color as it looks like there are two bond
wires and two LED dies in it.

There seems to be significant manual assembly needed for these, as it
would
be hard for a robot /selective solder to solder many of the through hole
components (LEDs, inline header, ground wire, connector going to the
outside
for your PCB, RJ45 pins (they are SMT on both sides of the board), the
transformer wires (these may be wave or selective soldered)).

Yeah. The board-board pins are stiff, old cordwood style. Must be hell
to rework.


Hot air will make rework simple, as well as a really wide tip that can touch
all pins at once.

The manually
assembled parts look to have significant weird looking flux residue
around
them, at least on the blue board.

Ugly yellow no-clean flux everywhere.

I'm surprised they did not clean them - this product is generally meant for
low volume specialized equipment that is intended to have a fairly long
lifetime. I generally encourage people to wash the boards if the product is
intended to last more then 5 years, and especially if it will not be used in
an reasonably controlled environment with reasonable humidity.

It's a different story when your building mass produced consumer stuff
(junk?) where profit is low and unfortunately the product life time is
measured in months.




Weird ground wire (I assume) going to the rear case.

Right.


I am quite surprised they used a 1.6 mm thick PCB, and one close to it. I
suppose they have the room (there is surprisingly a lot of room left
over).
The simple top PCB is at least a 4 layer PCB.

It's weird they used a custom set of pulse transformers and potted them
to
the PCB. They must have had problems finding one small enough, but then
again the ones in PCMCIA cards were quite small.

I'm surprised the Atmel memory IC is a BGA - all the ones I've currently
used and seen were CASON 8 or oversized body SO8's

Balls on the top ic are directly opposite balls on the other one.
Ballsy, somebody called it.

That is a bit "Ballsy". The BGA on the bottom of a double sided reflow (this
is when one side of a PCB is built completely, and then the other side is
built - as in the case of about 99% of automated double sided PCB assembly)
will have it's balls stretched out as the solder ball surface tension holds
it from falling.

I don't know how that effects reliability as we don't encourage this type of
design, but a demo board from a large semiconductor manufacture had a BGA
that was on the bottom of a double sided reflow. The BGA had a flaky ball
and had to be brought up to reflow temperature on a rework station in the
upright orientation to fix it.

Placing BGA's opposite from one other could produce some interesting routing
and via issues, but if blind vias are used (which is likely, since I don't
see many vias, especially the ends of ones going to internal planes only),
that would be eliminated. The reflow profile could get a little tricky, but
the parts are small in this application, so I doubt that would be an area of
concern.



There are a bunch of 0402's. The pads width and overall length looks
good,
but the gap between the two pads looks a little large - possible
tombstone
or worse, drawbridge problems, but without having the actual dimensions
or
looking at the board in more detail, it's hard to say.

There is no evidence of something getting hot - usually the PCB will
darken
in high heat areas, and if really hot, the solder joints will melt a bit,
giving a cold solder / wrinkly look to them

Every once in a while, Icc would jump up and the case would go up to
80C or so. It still worked, mostly. It would take a power cycle to
reset it. Sure sounds like cmos latchup to me.

That sounds like latchup also - Maybe a flaky BGA ball caused it ;-)

Standard factory
reaction, "that's never happened before."

John

In alt.binaries.schematics.electronic, John Larkin wrote:
This is the Lantronix Xport module.

http://www.lantronix.com/device-netw...ers/xport.html

This particuler unit randomly, a couple of times a week maybe, draws a
lot of power and gets very hot, 80C or so, and still works, but
flakily. So we decided to rip it open and see what's inside.

I love those LEDs.


yeah, why so long, why not long leads instead?

The two chips are a Lantronix thing and an Atmel serial flash. So
there must be a heap of ram inside the Lantronix chip, enough for the
tcp/ip stack and the jvm and all that.

I note some discolouration on the corner of the lantronix chip in the
microscope photo (X9). Is that normal?

Bye.
Jasen

On 6 May 2007 03:31:54 GMT, jasen wrote:

In alt.binaries.schematics.electronic, John Larkin wrote:
This is the Lantronix Xport module.

http://www.lantronix.com/device-netw...ers/xport.html

This particuler unit randomly, a couple of times a week maybe, draws a
lot of power and gets very hot, 80C or so, and still works, but
flakily. So we decided to rip it open and see what's inside.

I love those LEDs.


yeah, why so long, why not long leads instead?

The two chips are a Lantronix thing and an Atmel serial flash. So
there must be a heap of ram inside the Lantronix chip, enough for the
tcp/ip stack and the jvm and all that.

I note some discolouration on the corner of the lantronix chip in the
microscope photo (X9). Is that normal?


I think that was flux. It came off with acetone on a q-tip and the
chip isn't discolored, so that wasn't the hot spot.

Oh, I found the clock, hiding under the connector pins.

John

"John Larkin" wrote in message
...
On 6 May 2007 03:31:54 GMT, jasen wrote:

In alt.binaries.schematics.electronic, John Larkin
wrote:
This is the Lantronix Xport module.


http://www.lantronix.com/device-netw...vers/xport.htm
l

This particuler unit randomly, a couple of times a week maybe, draws a
lot of power and gets very hot, 80C or so, and still works, but
flakily. So we decided to rip it open and see what's inside.

I love those LEDs.


yeah, why so long, why not long leads instead?

Plastic is cheaper then metal, and plastic has the benefit of being
insulated, and not allowing the leads to touch themselves or the case. The
light flows through the plastic with very little loss.


The two chips are a Lantronix thing and an Atmel serial flash. So
there must be a heap of ram inside the Lantronix chip, enough for the
tcp/ip stack and the jvm and all that.

I note some discolouration on the corner of the lantronix chip in the
microscope photo (X9). Is that normal?

If there is local discoloration on a IC from internal heat buildup, there is
a 99.9% chance the IC is completely dead.



I think that was flux. It came off with acetone on a q-tip and the
chip isn't discolored, so that wasn't the hot spot.

Do you have an X ray machine to look at the insides of the board and to look
at the solder balls on the BGAs?


Oh, I found the clock, hiding under the connector pins.

John

On Fri, 04 May 2007 20:50:40 -0700, John Larkin wrote:

This is the Lantronix Xport module.

http://www.lantronix.com/device-netw...ers/xport.html

This particuler unit randomly, a couple of times a week maybe, draws a
lot of power and gets very hot, 80C or so, and still works, but
flakily. So we decided to rip it open and see what's inside.


EWWWWW!!!!!

From the web page:
quote
....
Management
SNMP, Telnet, serial, internal web server, and Microsoft Windows®-based
^^^^^^^^^^^^^^^^^^^^^^^^
utility for configuration
....
Included Software
MS Windows®-based DeviceInstaller software device installer and MS
^^^^^^^^^^^^^^^^^ ^^
Windows-based Comm Port Redirector
^^^^^^^^^^^^^
....
/quote
[emphasis added]

I think I've found your problem. ;-)

Cheers!
Rich

On Mon, 07 May 2007 07:07:30 +0000, Jeff L wrote:

Do you have an X ray machine to look at the insides of the board and to look
at the solder balls on the BGAs?


I noticed the leftmost solder ball on the upper chip - it looks like it
has a very dark fillet, which looks almost like a gap.

But then it wouldn't have worked at all, would it? ;-)

Thanks,
Rich

On Mon, 07 May 2007 18:04:20 GMT, Rich Grise wrote:

On Fri, 04 May 2007 20:50:40 -0700, John Larkin wrote:

This is the Lantronix Xport module.

http://www.lantronix.com/device-netw...ers/xport.html

This particuler unit randomly, a couple of times a week maybe, draws a
lot of power and gets very hot, 80C or so, and still works, but
flakily. So we decided to rip it open and see what's inside.


EWWWWW!!!!!

From the web page:
quote
...
Management
SNMP, Telnet, serial, internal web server, and Microsoft Windows®-based
^^^^^^^^^^^^^^^^^^^^^^^^
utility for configuration
...
Included Software
MS Windows®-based DeviceInstaller software device installer and MS
^^^^^^^^^^^^^^^^^ ^^
Windows-based Comm Port Redirector
^^^^^^^^^^^^^
...
/quote
[emphasis added]

I think I've found your problem. ;-)

Cheers!
Rich

The gadget itself doesn't run Windows, but the PC setup utilities sure
do. Actually, you only need to run one Windows program to find an
Xport on the network and set its IP address. After that, any browser
can open it as a web page and finish all the setups... baud rates,
Telnet/UDP/whatever, packet sizes, timeouts, all that.

You can also do the setups over the local serial port and never use
Windows, although that's more work.

Once it's set up, you can talk Telnet or binary or whatever to it, and
it in turn talks serial to its host device. It's really pretty slick.

John

In message , John Larkin
writes
Once it's set up, you can talk Telnet or binary or whatever to it, and
it in turn talks serial to its host device. It's really pretty slick.

They're a nice gadget, one of our customers integrates them into a
security product for remote management via the web interface and they
work really well apparently, I'm just waiting for some to get swapped
out so I can play with the 'dead' ones, got a couple of ideas for them.
Hell, if I get time I might even *buy* some.
John


--
Clint Sharp

We looked at using the Xport module but at $49 in quantity, it was too
expensive to put in a product. We did settle on the Microchip PIC18F97J60.
One of our guys is a whiz at the PIC series. We bought the C18 compiler and
the ICD2 emulator, the rest of the design environment and TCP/IP stack are
FREE! Depending how you package it, will take a bit more space than the
Xport but is about half the price (or less) in quantity.
Oppie

"John Larkin" wrote in message
...
This is the Lantronix Xport module.

http://www.lantronix.com/device-netw...ers/xport.html

This particuler unit randomly, a couple of times a week maybe, draws a
lot of power and gets very hot, 80C or so, and still works, but
flakily. So we decided to rip it open and see what's inside.

I love those LEDs.

The two chips are a Lantronix thing and an Atmel serial flash. So
there must be a heap of ram inside the Lantronix chip, enough for the
tcp/ip stack and the jvm and all that.

I scaled the pic res down, as the original files were huge.

John

On Wed, 9 May 2007 15:59:32 -0400, "Oppie" wrote:

We looked at using the Xport module but at $49 in quantity, it was too
expensive to put in a product. We did settle on the Microchip PIC18F97J60.
One of our guys is a whiz at the PIC series. We bought the C18 compiler and
the ICD2 emulator, the rest of the design environment and TCP/IP stack are
FREE! Depending how you package it, will take a bit more space than the
Xport but is about half the price (or less) in quantity.
Oppie


We just charge the customers $250 for it and use our engineering for
other stuff. If we were doing lower cost, higher-volume products, we
might spin our own.

John