Searching \ for 'Subject: [EE] Nailed it! - Regarding faulty segmen' in subject line. ()
Make payments with PayPal - it's fast, free and secure! Help us get a faster server
FAQ page: www.piclist.com/techref/index.htm?key=nailed+regarding
Search entire site for: 'Subject: [EE] Nailed it! - Regarding faulty segmen'.

Truncated match.
PICList Thread
'Subject: [EE] Nailed it! - Regarding faulty segmen'
2011\04\22@001127 by RussellMc

face picon face
1. This was rejected due to 390kB attached file. Files need to be <= ~ 30 kB
to get posted.
Sending on without photo in interests of getting it on list.

2. Changing subject line mid-thread is generally held to be 'bad form' -
expression of joy can be just as effective in body of text under old subject
line.

3. VERY important.

Changing R130 yourself is about 101.9% liable to invalidate any warranty and
also any request for replacement.

As the board runs OK enough as is you'd be best advised to leave it
untouched and contact them when available. that way you MAY get a
replacement board.

You can declaim all you wish about what you would LIKE them to do or about
what they SHOULD do but your situation is exceeedingly time honoured and
it's generally held as a reasonable compromise that they replace your
product like for like or repair it BUT that if you attempt self repair all
obligations are terminated. You may manage to improve on that but if you
attempt to do so the risk lies with you and YMMNV.

         R


---------- Forwarded message ----------
From: <spam_OUTpiclist-ownerTakeThisOuTspammit.edu>
Date: 22 April 2011 15:18


  Reason:  Message body is too big: 542635 bytes with a limit of 40 KB


---------- Forwarded message ----------
From: V G <.....x.solarwind.xKILLspamspam@spam@gmail.com>
To: PICLIST <piclistspamKILLspammit.edu>
Date: Thu, 21 Apr 2011 23:17:51 -0400
Subject: [EE] Nailed it! - Regarding faulty segment on Nexys 2 board
On Thu, Apr 21, 2011 at 8:18 PM, Spehro Pefhany <.....speffKILLspamspam.....interlog.com> wrote:

{Quote hidden}

I guess your long shot was the solution. I first measured all the voltages
on the pis using an oscilloscope and everything looked fine, including the
voltage drops across each segment. Then I measured each of the resistor
values using an ohm meter. R130 measured to be 2.2k, but it should be 100
ohms.

Where to go from here? I have a "defective" board and it's under warranty. I
wouldn't mind a free board, so I'll go pester Digilent while I search for
another 100 ohm resistor. Kinda makes me question what other "defects" my
board came with...

Anyway, I linked a picture of the resistors beside a ruler. What size are
these resistors? As in, what size should I look for when looking for a
replacement? Also, I doubt my local electronics store carries such small
resistors anyway, so this is going to be a real pain in the ass.

Picture: http://postimage.org/image/2dfsy9sn8/

Also, many thanks to Mr. Sean Breheny for the awesome oscilloscope. Made
debugging this board a breeze

2011\04\22@002636 by V G

picon face
On Fri, Apr 22, 2011 at 12:10 AM, RussellMc <apptechnzspamspam_OUTgmail.com> wrote:

> 1. This was rejected due to 390kB attached file. Files need to be <= ~ 30
> kB
> to get posted.
> Sending on without photo in interests of getting it on list.
>

That's a real pain in the ass. You'd think MIT has enough bandwidth to
forward message with a 1MB photo.


{Quote hidden}

Thanks. I wasn't going to change it until I got a response that I liked from
them

2011\04\22@011849 by RussellMc

face picon face
> That's a real pain in the ass. You'd think MIT has enough bandwidth to
> forward message with a 1MB photo.

At 2000 users getting that amounts to about 2 GB of bandwidth per MB of file.
Do that a few million times and after a while it starts to mount up
towards real traffic.
:-)

> Thanks. I wasn't going to change it until I got a response that I liked from
> them.

Aha. Wisdom is winning through!
Very good :-).


         Russel

2011\04\22@013645 by V G

picon face
On Fri, Apr 22, 2011 at 1:18 AM, RussellMc <@spam@apptechnzKILLspamspamgmail.com> wrote:

>  At 2000 users getting that amounts to about 2 GB of bandwidth per MB of
> file.
> Do that a few million times and after a while it starts to mount up
> towards real traffic.
> :-)
>

Why would it be a few million times? I mean, people rarely upload
attachments

2011\04\22@020423 by RussellMc

face picon face
>>  At 2000 users getting that amounts to about 2 GB of bandwidth per MB of
>> file.

>> Do that a few million times and after a while it starts to mount up
>> towards real traffic.
>> :-)

> Why would it be a few million times? I mean, people rarely upload
> attachments.

That was a purposeful misquote of a very time honoured punch line.
It went something like "10 million dollars here and 10 million dollars
there and after a while it starts to mount up to serious money"

My point, of sorts, was that even 2 GB bandwidth use on sending out
one photo, which could have been 30 times smaller and still effective
enough, is quite a lot of waste bandwidth in its own right. And it
would make a significant difference if all the 30 kB files were
instead 1 to 2 MB.



 R

2011\04\22@021244 by cdb

flavicon
face


:: Why would it be a few million times? I mean, people rarely upload
:: attachments.

Creep! Not you, but usage. People may rarely upload attachments now, because it isn't easy and the results now wonderful, make it easy and people will soon take advantage of it.

"Give a man space, and he'll fill it"!

Colin

PS, I suppose I'll have to change that to "Give a non gendered being space and it will be filled"
--
cdb, KILLspamcolinKILLspamspambtech-online.co.uk on 22/04/2011
Web presence: http://www.btech-online.co.uk   Hosted by:  http://www.justhost.com.au
 

2011\04\22@024738 by V G

picon face
On Fri, Apr 22, 2011 at 2:12 AM, cdb <RemoveMEcolinTakeThisOuTspambtech-online.co.uk> wrote:

>
>
> :: Why would it be a few million times? I mean, people rarely upload
> :: attachments.
>
> Creep! Not you, but usage. People may rarely upload attachments now,
> because it isn't easy and the results now wonderful, make it easy and
> people will soon take advantage of it.
>
> "Give a man space, and he'll fill it"!
>
>
Well 30KB is very small. A more useful figure would be 200KB or so which is
more than reasonable for MIT servers to handle

2011\04\22@030748 by Michael Watterson

face picon face
On 22/04/2011 05:26, V G wrote:
> That's a real pain in the ass. You'd think MIT has enough bandwidth to
> forward message with a 1MB photo.
>

It becomes 2Gbyte when forwarded.

if that was 4x a day for a month = 240Gbyte..

2011\04\22@030951 by Michael Watterson

face picon face
On 22/04/2011 06:36, V G wrote:
> On Fri, Apr 22, 2011 at 1:18 AM, RussellMc<spamBeGoneapptechnzspamBeGonespamgmail.com>  wrote:
>
>>   At 2000 users getting that amounts to about 2 GB of bandwidth per MB of
>> file.
>> Do that a few million times and after a while it starts to mount up
>> towards real traffic.
>> :-)
>>
> Why would it be a few million times? I mean, people rarely upload
> attachments.

If the limit was higher they would frequently instead of own storage and link, which is more efficient as only a minority may wish the attachment.

2011\04\22@031502 by Michael Watterson

face picon face
On 22/04/2011 07:47, V G wrote:
> Well 30KB is very small. A more useful figure would be 200KB or so which is
> more than reasonable for MIT servers to handle.

If if was my system I'd pick 30K rather than 200k for a mailing system as explained above.

Forum / Web page upload can be higher as the file/image is not automatically downloaded by everyone.

Users on Dialup might not like to receive 30 x 200kByte  or  30 x 1MByte images on bad days. With a link they can choose.

The logic for sizes of stuff is very different on a mailing list than Web based community. (Web based many users may not visit at all regularly, mailing list everyone gets copy even if currently not actually reading the stuff)

2011\04\22@080948 by Olin Lathrop

face picon face
V G wrote:
>>> 1. This was rejected due to 390kB attached file. Files need to be
>>> <= ~ 30 kB to get posted.

Duh.  Trying to send 400kB to this list is way beyond spec.

>> Sending on without photo in interests of getting it on list.

Russell, you are once again shorting out the list's intelligence filter.
Please stop doing that.

> That's a real pain in the ass.

No, it's just common sense.

> You'd think MIT has enough bandwidth to
> forward message with a 1MB photo.

You'd think anyone that knows how to spell PIC would understand why that's a
dumb idea.

When you measured the resistor, was the board powered down for long enough
so that any residual charge couldn't be fooling the ohmmeter?  To test your
theory, you can temporarily parallel the resistor in question with another
one just by holding its leads accross it.  This won't hurt your chance of
getting a replacement since you're not actually altering the board and they
have no way of knowing you did this.

While a misloaded part can happen, it is rather unlikely to make it all the
way to the end customer.  If it really is a misloaded resistor, then most
likely a whole batch of boards have the same error.  Chances are that they
are already aware of the problem.  If so, they will probably exchange your
board for a new one without fuss.


********************************************************************
Embed Inc, Littleton Massachusetts, http://www.embedinc.com/products
(978) 742-9014.  Gold level PIC consultants since 2000

2011\04\22@081747 by Olin Lathrop

face picon face
V G wrote:
> Well 30KB is very small. A more useful figure would be 200KB or so
> which is more than reasonable for MIT servers to handle.

30kB is enough for a small line drawing in a suitable image format.

In general, put your photo on a server someplace and post a link to it.
That's much more efficient, and you aren't forcing it on people's bandwidth
before they decide they care enough to click on the link.  This is very easy
to do, so there's no excuse.


********************************************************************
Embed Inc, Littleton Massachusetts, http://www.embedinc.com/products
(978) 742-9014.  Gold level PIC consultants since 2000

2011\04\22@100439 by IVP

face picon face
> What size are these resistors?

They look like 0402. Don't know if you could buy them retail
at a typical general outlet. If you could, maybe not individually.
For example Radiospares sell 10,000 @ 0.03, 50 @ 0.1

2011\04\22@105743 by Sergey Dryga

flavicon
face
Olin Lathrop <olin_piclist <at> embedinc.com> writes:


> > That's a real pain in the ass.
>
> No, it's just common sense.
>
One man's common sense, other man's pain in the ass.

> > You'd think MIT has enough bandwidth to
> > forward message with a 1MB photo.
>
> You'd think anyone that knows how to spell PIC would understand why that's a
> dumb idea.
>
I, for one, like to think that I can spell PIC, but I still do not accept the
argument about bandwidth limitation.  If MIT server cannot handle extra 2Gb,
let's move to another server.  For example, hosting company where I keep my
domain http://beaglerobotics.com, has unlimited bandwidth.  <<1MB limit seems so
1995.

The other problem with large image attachments is that it might clutter email
boxes.  But that is easily controlled on the level of email client.

Overall, I think that in most cases a large image does not provide a significant
benefit over a small one, but bandwidth argument is not the right one to use.
Sergey Dryga
http://beaglerobotics.com

2011\04\22@113005 by Michael Watterson

face picon face
On 22/04/2011 15:57, Sergey Dryga wrote:
> I, for one, like to think that I can spell PIC, but I still do not accept the
> argument about bandwidth limitation.  If MIT server cannot handle extra 2Gb,

It could be more like 240Gbyte a month. Also it's not simple handling attachments separate from message body for most clients and POP3.

Far better that there is link to large content. Especially for people only with Dialup or Mobile Internet which is still over 45% of users in some so called Developed Countries, never mind so called "developing" ones

2011\04\22@113633 by IVP

face picon face
> What size are these resistors?

They look like 0402. Don't know if you could buy them retail
at a typical general outlet. If you could, maybe not individually.
For example Radiospares sell 10,000 @ 0.03, 50 @ 0.1

2011\04\22@133939 by V G

picon face
On Fri, Apr 22, 2011 at 9:55 AM, IVP <TakeThisOuTjoecolquittEraseMEspamspam_OUTclear.net.nz> wrote:

> > What size are these resistors?
>
> They look like 0402. Don't know if you could buy them retail
> at a typical general outlet. If you could, maybe not individually.
> For example Radiospares sell 10,000 @ 0.03, 50 @ 0.19
>


Thanks! I called the guy and he said I can return it and get a replacement,
but I don't want to go through the hassle.

Anyway, I re-measured the resistor after Olin's doubt that I waited long
enough after the board was powered off. This is what I found:

The resistor *may* actually be a 100 ohm resistor but could have been
defective out the manufacturing plant OR could be a cold solder joint for
the following reasons:

When I initially touched the ohm meter leads to all other 100 ohm resistors,
the reading was instantly 100 ohms regardless of how much pressure I put on
the leads. When I touched it to R130, initial value was around 3k, but as I
increased pressure on the solder joint (maybe from 0.1 to about 1 kg of
"weight" from my arms), the resistance of R130 quickly dropped.

If it's simply a matter of reheating the solder joint, I don't want to
bother with the hassle of sending it back and getting a replacement. But is
there a possibility that the resistor itself is defective

2011\04\22@134450 by V G

picon face
On Fri, Apr 22, 2011 at 1:39 PM, V G <RemoveMEx.solarwind.xspamTakeThisOuTgmail.com> wrote:

{Quote hidden}

Another update. Tested again with the board powered on. If I press down on
R130 with my finger nail, the segments work as they should. Seems like a
cold solder joint. I'll just go ahead and reheat the joints

2011\04\22@135840 by Oli Glaser

flavicon
face
On 22/04/2011 18:39, V G wrote:
{Quote hidden}

Unlikely the resistor is internally defective. Far more likely it's dry joint, especially if the reading changes with pressure.
Personally, I would get a fine tip and reflow the joints, but be very careful (hold the resistor with tweezers or apply pressure with something to keep it in place - they can stick to the tip when the solder reflows)
 If you are not sure/confident I would just leave it as is, after all it's only a cosmetic issue.
From the picture it looks not too hard, as the board is sparsely populated. I guess even if you get it wrong, worst case scenario is your display is missing a segment, unless Murphy gets involved of course..  :-)

2011\04\22@141133 by Dwayne Reid

flavicon
face
At 11:36 PM 4/21/2011, V G wrote:

>Why would it be a few million times? I mean, people rarely upload
>attachments.

Sadly, you are mistaken.  I'm on a bunch of mailing lists (mostly Yahoo Groups) and I get a TON of attachments every week (several each day).  Every few months, I take a day and weed them out - disposing of the ones that are of no interest but keeping the ones are useful.

Just looking now: my attachments folder in Eudora is says that there are 6002 objects occupying 984MB.  That does not include the 3644 files occupying 68MB in the Embedded directory (images embedded within messages).

dwayne

-- Dwayne Reid   <RemoveMEdwaynerEraseMEspamEraseMEplanet.eon.net>
Trinity Electronics Systems Ltd    Edmonton, AB, CANADA
(780) 489-3199 voice          (780) 487-6397 fax
http://www.trinity-electronics.com
Custom Electronics Design and Manufacturing

2011\04\22@141407 by Dwayne Reid

flavicon
face
At 06:10 AM 4/22/2011, Olin Lathrop wrote:

>When you measured the resistor, was the board powered down for long enough
>so that any residual charge couldn't be fooling the ohmmeter?  To test your
>theory, you can temporarily parallel the resistor in question with another
>one just by holding its leads accross it.  This won't hurt your chance of
>getting a replacement since you're not actually altering the board and they
>have no way of knowing you did this.

The easier way to check for residual voltage is to simply swap the meter leads.  Any residual voltage will cause the two readings to vary significantly.

dwayne

-- Dwayne Reid   <RemoveMEdwaynerspam_OUTspamKILLspamplanet.eon.net>
Trinity Electronics Systems Ltd    Edmonton, AB, CANADA
(780) 489-3199 voice          (780) 487-6397 fax
http://www.trinity-electronics.com
Custom Electronics Design and Manufacturing

2011\04\22@141759 by Dwayne Reid

flavicon
face
At 11:44 AM 4/22/2011, V G wrote:

>Another update. Tested again with the board powered on. If I press down on
>R130 with my finger nail, the segments work as they should. Seems like a
>cold solder joint. I'll just go ahead and reheat the joints.

It could also be a cracked resistor body.  You'll find out as soon as you heat one end - if the resistor fall apart, just remove the other half and solder in a new part.

I have 100R in 0603 if you need - just send a private email with your address and I'll tape some to a piece of paper and send it to you.

dwayne

-- Dwayne Reid   <RemoveMEdwaynerTakeThisOuTspamspamplanet.eon.net>
Trinity Electronics Systems Ltd    Edmonton, AB, CANADA
(780) 489-3199 voice          (780) 487-6397 fax
http://www.trinity-electronics.com
Custom Electronics Design and Manufacturing

2011\04\22@160958 by Spehro Pefhany

picon face
At 02:14 PM 4/22/2011, you wrote:
>At 06:10 AM 4/22/2011, Olin Lathrop wrote:
>
> >When you measured the resistor, was the board powered down for long enough
> >so that any residual charge couldn't be fooling the ohmmeter?  To test your
> >theory, you can temporarily parallel the resistor in question with another
> >one just by holding its leads accross it.  This won't hurt your chance of
> >getting a replacement since you're not actually altering the board and they
> >have no way of knowing you did this.
>
>The easier way to check for residual voltage is to simply swap the
>meter leads.  Any residual voltage will cause the two readings to
>vary significantly.

Sure..it perhaps should be noted that the idea of finding any significant
residual voltage across a 100 Ohm resistor is a bit far-fetched unless there
are capacitors of >10,000uF lurking around, or unless you are really
quick about it.

>Best regards,

Spehro Pefhany --"it's the network..."            "The Journey is the reward"
EraseMEspeffspamspamspamBeGoneinterlog.com             Info for manufacturers: http://www.trexon.com
Embedded software/hardware/analog  Info for designers:  http://www.speff.com

2011\04\22@163249 by Dwayne Reid

flavicon
face
At 02:09 PM 4/22/2011, Spehro Pefhany wrote:
{Quote hidden}

Actually, the idea was to find out why the resistance value was so high.  In other words, it wasn't actually a 100R resistor (unless pressure was applied).

dwayne

-- Dwayne Reid   <RemoveMEdwaynerKILLspamspamplanet.eon.net>
Trinity Electronics Systems Ltd    Edmonton, AB, CANADA
(780) 489-3199 voice          (780) 487-6397 fax
http://www.trinity-electronics.com
Custom Electronics Design and Manufacturing

2011\04\22@190645 by IVP

face picon face
> From the picture it looks not too hard, as the board is sparsely
> populated

Given the space available I did wonder why they went so small

But I'm a person, not a pick and place machine

2011\04\22@200936 by IVP

face picon face
> If it's simply a matter of reheating the solder joint

It might pay to check other joints too. I've had a couple of
products with weak soldering.on one or two components
and figured it was worth a little time to re-heat what I could

Be careful. As Oli said, they will come off quite easily and
stick to the iron.
My special tool that comes in handy for all sorts of PCB work
is this, a big needle epoxied into a pen case

http://home.clear.net.nz/pages/joecolquitt/needle-pen.jpg

Great for editing boards (for example making fine lines in art
work and scratching out bridges) and holding down tiny part

2011\04\22@202552 by Oli Glaser

flavicon
face
On 23/04/2011 01:09, IVP wrote:
> My special tool that comes in handy for all sorts of PCB work
> is this, a big needle epoxied into a pen case
>
> http://home.clear.net.nz/pages/joecolquitt/needle-pen.jpg
>
> Great for editing boards (for example making fine lines in art
> work and scratching out bridges) and holding down tiny parts

That's an ingenious little tool, might have to make one of those...
(I wonder how much RS would charge for some carbon tipped version with a fancy name :-)  )

2011\04\22@203412 by V G

picon face
On Fri, Apr 22, 2011 at 8:09 PM, IVP <joecolquittSTOPspamspamspam_OUTclear.net.nz> wrote:

> > If it's simply a matter of reheating the solder joint
>
> It might pay to check other joints too. I've had a couple of
> products with weak soldering.on one or two components
> and figured it was worth a little time to re-heat what I could
>
> Be careful. As Oli said, they will come off quite easily and
> stick to the iron.
>
> My special tool that comes in handy for all sorts of PCB work
> is this, a big needle epoxied into a pen case
>
> http://home.clear.net.nz/pages/joecolquitt/needle-pen.jpg
>
> Great for editing boards (for example making fine lines in art
> work and scratching out bridges) and holding down tiny parts
>
>

Thanks! I have needle-sharp tweezers from DealExtreme that should also do
the trick

2011\04\22@210525 by RussellMc

face picon face
> Thanks! I have needle-sharp tweezers from DealExtreme that should also do
> the trick.

I didn't know DealExtreme did free samples:-)

2011\04\22@221035 by V G

picon face
On Fri, Apr 22, 2011 at 9:04 PM, RussellMc <spamBeGoneapptechnzSTOPspamspamEraseMEgmail.com> wrote:

> > Thanks! I have needle-sharp tweezers from DealExtreme that should also do
> > the trick.
>
> I didn't know DealExtreme did free samples:-)
>
>
I see what you're trying to poke at. But they have free shipping and cheap
prices for relatively good quality items, so I buy their stuff

More... (looser matching)
- Last day of these posts
- In 2011 , 2012 only
- Today
- New search...