Analogue-sequencer

I have just been using my P3 again and noticed some very weird 
behaviour from the display...the sequencer appeared to function as 
normal though. Some of the things i saw were :

Pressed play/edit to go out of edit mode and the duisplay showed tap 
in the top left corner and nc on the bottom left and in the top 
right it displayed esol. I then hit F3 to lose which seemed to work 
but then the display showed across the bottom /1  enuf STF  kn

I also at one point pressed F2 to change direction to reversea but 
the display continued to show forward...allthough the direction 
changed, i then pressed F2 again and it showed forreverseb

On startup as well the //////P3///// has stayed on display after it 
should dissapear.

I have also noticed some garbage characters at times so im not sure 
if its just P3 data getting screwed up.

The only things I have done have been to upgrade to the new 
bootloader 3.3 and OS 3.1.006c last night. I also dimmed the display 
a bit as it was a bit too bright.

I did a quick rest of cables allthough they all seemed to be ok so 
im not sure if its maybe a cable issue, possible short between a 
solder somewhere on the PLED pcb or hopefully not something worse to 
do with the OS.

Does anyone have any suggestions on what to check\test next?

thanks alot
Brett

Hi Brett,

I think the first thing to do is perform a memory initilialisation by 
holding F1 and step key 7, then powering on the P3. Continue holding 
the keys until the display shows 'Wiping ALL Data!', then press both 
F1 and F2 to confirm.

This should flush out any residual garbage in your sequencer RAM.

HTH

Andy


On 6 Nov 2006 at 7:14, bambam4236 wrote:
> Does anyone have any suggestions on what to check\test next?

---

Andy Wilson
http://www.techman.synth.net
techman@synth.net

Thanks Andy

It seemed to come good but i flashed it anyway and used it for a 
good 4 hours straight yesterday with no problem ;)
I just hope the problems gone and i dont have one of those things 
that reasrs its ugly head every few weeks!

Thanks for the advice
Brett

--- In analogue-sequencer@yahoogroups.com, "Andy Wilson" 
<techman@...> wrote:
>
> Hi Brett,
> 
> I think the first thing to do is perform a memory initilialisation 
by 
> holding F1 and step key 7, then powering on the P3. Continue 
holding 
> the keys until the display shows 'Wiping ALL Data!', then press 
both 

> F1 and F2 to confirm.
> 
> This should flush out any residual garbage in your sequencer RAM.
> 
> HTH
> 
> Andy
> 
> 
> On 6 Nov 2006 at 7:14, bambam4236 wrote:
> > Does anyone have any suggestions on what to check\test next?
> 
> ---
> 
> Andy Wilson
> http://www.techman.synth.net
> techman@...
>

> I have just been using my P3 again and noticed some very weird 
> behaviour from the display...the sequencer appeared to function as 
> normal though. Some of the things i saw were :

The display module is a little computer in its own right.
Weirdness of the sort you describe is usually caused by errors in the data
transfer from the main P3 CPU to the module CPU.
I've seen this happen with ribbon cables where there was a poor connection
on one of the data lines - fixed by replacing the ribbon cable.
Also make sure your ribbon cable isn't excessively long.

One other cause of this problem seen in earlier revision P3s is the
transistor used to drive the display ENABLE line.
In a couple of cases, the gain of the transistor used was below spec, and
the signal therefore wasn't fast enough to work reliably.
This only applies to boards before revision 1.6.
The transistor in question is Q1 - you can improve the performance by
driving it harder - change R20 from 22k to 10k.
Or just put in a transistor with better hfe.

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

Hi colin

i have a newer one so i dont think its the transistor and after 
playing around with it a bit more and double checking and recrimping 
the cable it appears to work fine...if it returns ill try a new 
cable.
Thanks again for the info and hope you enjoyed your trip.

Brett

--- In analogue-sequencer@yahoogroups.com, "Colin Fraser" 
<colin@...> wrote:
>
>  
> > I have just been using my P3 again and noticed some very weird 
> > behaviour from the display...the sequencer appeared to function 
as 
> > normal though. Some of the things i saw were :
> 
> The display module is a little computer in its own right.
> Weirdness of the sort you describe is usually caused by errors in 
the data
> transfer from the main P3 CPU to the module CPU.
> I've seen this happen with ribbon cables where there was a poor 
connection
> on one of the data lines - fixed by replacing the ribbon cable.
> Also make sure your ribbon cable isn't excessively long.
> 
> One other cause of this problem seen in earlier revision P3s is the
> transistor used to drive the display ENABLE line.
> In a couple of cases, the gain of the transistor used was below 
spec, and
> the signal therefore wasn't fast enough to work reliably.
> This only applies to boards before revision 1.6.
> The transistor in question is Q1 - you can improve the performance 
by

> driving it harder - change R20 from 22k to 10k.
> Or just put in a transistor with better hfe.
> 
> Best regards,
> Colin Fraser
> Sequentix Music Systems Ltd
> http://www.sequentix.com
>

Hmm its back again to haunt me so replacing the cable didnt fix it. 
I got drastic last night and swapped the display for a spare i 
bought just in case id need it in the future.
Its back to normal again..................for now. If it stays fixed 
do you think it may have been a faulty display or would you still 
suggest possibly a faulty connection somewhere still? I only ask 
becaus i might try to return the display to where i got it.

cheers
Brett

--- In analogue-sequencer@yahoogroups.com, "bambam4236" 
<hotbambam@...> wrote:
>
> Hi colin
> 
> i have a newer one so i dont think its the transistor and after 
> playing around with it a bit more and double checking and 
recrimping 
> the cable it appears to work fine...if it returns ill try a new 
> cable.
> Thanks again for the info and hope you enjoyed your trip.
> 
> Brett
> 
> --- In analogue-sequencer@yahoogroups.com, "Colin Fraser" 
> <colin@> wrote:
> >
> >  
> > > I have just been using my P3 again and noticed some very weird 
> > > behaviour from the display...the sequencer appeared to 
function 
> as 
> > > normal though. Some of the things i saw were :
> > 
> > The display module is a little computer in its own right.
> > Weirdness of the sort you describe is usually caused by errors 
in 
> the data
> > transfer from the main P3 CPU to the module CPU.
> > I've seen this happen with ribbon cables where there was a poor 
> connection
> > on one of the data lines - fixed by replacing the ribbon cable.
> > Also make sure your ribbon cable isn't excessively long.
> > 
> > One other cause of this problem seen in earlier revision P3s is 
the
> > transistor used to drive the display ENABLE line.
> > In a couple of cases, the gain of the transistor used was below 
> spec, and
> > the signal therefore wasn't fast enough to work reliably.
> > This only applies to boards before revision 1.6.
> > The transistor in question is Q1 - you can improve the 
performance 

> by
> > driving it harder - change R20 from 22k to 10k.
> > Or just put in a transistor with better hfe.
> > 
> > Best regards,
> > Colin Fraser
> > Sequentix Music Systems Ltd
> > http://www.sequentix.com
> >
>