Analogue-sequencer

Hey everyone... I'm working on building a P3 for a member of this
group using the v1.5 board set. Everything is going good thus far, but
I have two questions I'm hoping others here can help me with.

1) I believe that the PLED I have is failing. This display will
occasionally display nothing without a power cycling, usually doesn't
display a second row, seems to have fading at the edges of the
display, and the pixels seem smaller than usual. Can any of you
confirm that this is the behavior observed when your PLED(s) failed?

Here is a photo of the PLED when it displayed two rows of text, during
the bootloader update:
http://nuxx.net/gallery/v/stuffivemade/sequentix_p3_for_ivan/IMG_1168.jpg.html

Here's the PLED when it is displaying only one line of text:
http://nuxx.net/gallery/v/stuffivemade/sequentix_p3_for_ivan/IMG_1163.jpg.html

For reference, here's another photo of the PLED (same model) in my P3
from 2003. The display is even and bright with large pixels:
http://nuxx.net/gallery/v/stuffivemade/sequentix_p3/done/IMG_5006.JPG.html

Note that when the display is blank or missing the second line the P3
still functions as expected, the display just isn't correct.

2) On the construction page for the v1.5 mainboard
(http://www.sequentix.com/build/v1.5/cnst-main.htm), implementing MIDI
sync requires replacing D2 and D3 with 220pF caps in order to add a
bit of capacitance to avoid false triggering. I did not have any 220pF
parts available, so I used 330pF ceramic caps. Is this a suitable
replacement, or should I use something else? I do have two ~110pF
ceramic, if this is more suitable.

Thanks very much!

-Steve

--- In analogue-sequencer@yahoogroups.com, "Colin Fraser" <colin@...>
wrote:
> Is that a new part, or one that's been sitting for a while but
hasn't been
> used ?

Best I can tell it's a part that has been sitting for a while. This P3
is actually for an individual from these forums and it's been sitting
for a while before being build. I've got a second PLED at home to try,
but I'm thinking that the issue may be related simply to age and not
power-on time.

For what it's worth, I emailed these photos off to Crystalfontz this
morning asking if what is seen is indicative of a failing PLED. The
response I received indicated that yes, this sort of issue is what one
would expect to see.

Here's a PDF of the support ticket with Crystalfontz:
http://nuxx.net/pdf/ivan_p3_crystalfontz_pled_failure.pdf

I'll get a better image / screenshot of it uploaded later tonight once
I'm home.

I have a second one of Ivan's PLED modules at home and this evening
I'm going to replace the existing one (which was bolted into the case,
with the connector soldered to it) when I received the kit. I'm hoping
that one works better, but with the thoughts of failure simply being
related to age, I don't have much faith that it will.
 
> The value isn't critical, 330pF should be fine.

Thanks very much, that's reassuring. I'll just stick with those then.

-Steve

Hmm ... the PLED on my P3 failed a month or so ago; what happened is  
that individual pixels in the characters faded out and died - those  
which were on more often than the others - and then over the course of  
a couple of days the entire display went dark, as if all the remaining  
pixels died.

I have a little mini-hifi here with the same problem: because it says  
"FM" most of the time, whenever it displays something else the pixels  
are much brighter except those which comprise the "FM".

	-- N.


Nick Rothwell / Cassiel.com Limited
www.cassiel.com
www.myspace.com/cassieldotcom
www.last.fm/music/cassiel
www.reverbnation.com/cassiel
www.linkedin.com/in/cassiel
www.loadbang.net

Mine is starting to fade a little bit on the left, like that 1st picture
Steve posted,
but I haven't had the problem with the 2nd line missing (yet!)

On Tue, Apr 22, 2008 at 3:44 PM, Nick Rothwell <nick@cassiel.com> wrote:

>   Hmm ... the PLED on my P3 failed a month or so ago; what happened is
> that individual pixels in the characters faded out and died - those
> which were on more often than the others - and then over the course of
> a couple of days the entire display went dark, as if all the remaining
> pixels died.
>
> I have a little mini-hifi here with the same problem: because it says
> "FM" most of the time, whenever it displays something else the pixels
> are much brighter except those which comprise the "FM".
>
> -- N.
>
> Nick Rothwell / Cassiel.com Limited
> www.cassiel.com
> www.myspace.com/cassieldotcom
> www.last.fm/music/cassiel
> www.reverbnation.com/cassiel
> www.linkedin.com/in/cassiel
> www.loadbang.net
>
>  
>


[Non-text portions of this message have been removed]

Hi Steve, 

> 1) I believe that the PLED I have is failing. This display will
> occasionally display nothing without a power cycling, usually doesn't
> display a second row, seems to have fading at the edges of the
> display, and the pixels seem smaller than usual. Can any of you
> confirm that this is the behavior observed when your PLED(s) failed?

Is that a new part, or one that's been sitting for a while but hasn't been
used ?

> 2) On the construction page for the v1.5 mainboard
> (http://www.sequentix.com/build/v1.5/cnst-main.htm), implementing MIDI
> sync requires replacing D2 and D3 with 220pF caps in order to add a
> bit of capacitance to avoid false triggering. I did not have any 220pF
> parts available, so I used 330pF ceramic caps. Is this a suitable
> replacement, or should I use something else? I do have two ~110pF
> ceramic, if this is more suitable.

The value isn't critical, 330pF should be fine.

Best regards,
Colin Fraser
Sequentix Music Systems Ltd
http://www.sequentix.com

> Mine is starting to fade a little bit on the left, like that 
> 1st picture
> Steve posted,
> but I haven't had the problem with the 2nd line missing (yet!)

Fading is normal - each pixel has lifetime that reduces while it is turned
on.
According to the datasheet - "The Half-Brightness Decay life will longer
than 10k hours in room temp."
Experience suggests this claim was a bit optimistic.
The sudden failure mode that affects some displays is just the icing on the
'never use a new technology until it's had a few years to prove itself'
cake.

Best regards,
Colin Fraser
Sequentix Music Systems Ltd
http://www.sequentix.com

--- In analogue-sequencer@yahoogroups.com, "Colin Fraser" <colin@...>
wrote:
> Fading is normal - each pixel has lifetime that reduces while it is
turned
> on.
> According to the datasheet - "The Half-Brightness Decay life will longer
> than 10k hours in room temp."
> Experience suggests this claim was a bit optimistic.
> The sudden failure mode that affects some displays is just the icing
on the
> 'never use a new technology until it's had a few years to prove itself'
> cake.

As a follow-up to this and the other PLED posts today, I gave a brand
new, still in the pink bubble wrap and with the protective coating
PLED a go in Ivan's P3 and it is just simply blank. The P3 sees it
because it boots successfully, but the display shows nothing.

The production date on both of the PLEDs I've been working with in
this P3 is 19-Mar-2005. I'm thinking the issue is also related to
general age of the modules, not just power-on time.

Slightly related, the MIDIbox SID-NUXX design I did uses a 2x20 PLED
also from Crystalfontz, and all of those are still working just fine.
They were all purchased in mid-2006.

-Steve

--- In analogue-sequencer@yahoogroups.com, "Steve" <c0nsumer@...> wrote:
> 
> As a follow-up to this and the other PLED posts today, I gave a brand
> new, still in the pink bubble wrap and with the protective coating
> PLED a go in Ivan's P3 and it is just simply blank. The P3 sees it
> because it boots successfully, but the display shows nothing.
> 
> The production date on both of the PLEDs I've been working with in
> this P3 is 19-Mar-2005. I'm thinking the issue is also related to
> general age of the modules, not just power-on time.
> 

The crazy thing is that both of the PLEDs have never been powered up
before the past two days, and they're basically bad.  I have one more
unit from the same batch but probably won't bother trying it.  It
seems really odd that they go bad in storage!

Any idea if Crystalfontz is making good on these bad products?

Ivan

>>I'm thinking the issue is also related to general age of the
modules, not just power-on time.<<

I'm inclined to agree. my total p3-usage-time is spilt between two
machines which are in different studios, + also I have several other
machines with which to go bleep & bloop. my older p3 is now showing
signs of imminent PLED failure- the first four characters are as good
as ever but the entire rest of the display is now dimming alarmingly-
the individual pixels are quite distinctly visible, whereas previously
they were so bright as to be indistinguishable as separate light-sources.

I'll punt up a pic of this later.

here's the thing, though- both of my p3s are on v4, with the
screensaver, & have been for some months. I noticed the display in
this one was significantly worse after I'd left the machine for an
hour with the display dimmed.... so it doesn't seem to be wear-&-tear
causing this....

anyway. bottom line is, I guess I'll be needing a couple of the LCD
kits soon too. colin, how does one go about this? I'd be much happier
about our imminent US trip (mid-june) if I have this fixed first.

duncan.

> anyway. bottom line is, I guess I'll be needing a couple of the LCD
> kits soon too. colin, how does one go about this? I'd be much happier
> about our imminent US trip (mid-june) if I have this fixed first.

I should have had an order page for those kits up by now...
We're getting a garage conversion done starting next week, so I've been kept
busy trying to clear all the crap out of it, and get organised for the work
to start.
The conversion is for a new workshop/studio for me, so improved service can
resume once I'm in !
In the meantime, anyone desperately needing a display, mail me privately and
I'll sort you out.

Best regards,
Colin Fraser
Sequentix Music Systems Ltd
http://www.sequentix.com

On 1 May 2008, at 21:56, Colin Fraser wrote:

> The conversion is for a new workshop/studio for me, so improved  
> service can
> resume once I'm in !

P4!

	-- N.


Nick Rothwell / Cassiel.com Limited
www.cassiel.com
www.myspace.com/cassieldotcom
www.last.fm/music/cassiel
www.reverbnation.com/cassiel
www.linkedin.com/in/cassiel
www.loadbang.net