Synth-DIY Yahoo! Groups Archives

SDS7 question... "sometimes" no LED display on power up

2014-02-05 by <music@...>

Hi group....

Here's a baffling one...
I have a fully functional SDS7 (Ser# 71163) with an intermittent issue... when powered ON, sometimes the Front 2 digit LED Display above the Increment Knob on the Control Panel does not light up despite everything else normal. All buttons and LEDs are fully functional.

I've removed the Control Panel and tried a different one and cable that are known good.. and the same results. Out of 10 attempts, the LED remained unlit 3 times. I suspected a power supply issue and tried a different one with the same result. I've also tried the suspect Control Panel in another SDS7 and it worked fine, lighting up 100% of the time.

It appears that there might an issue with something on the SDS7's main board or other issue with the supply that powers the 2 digit LED display??

Thoughts?

Cheers
Alan

RE: SDS7 question... "sometimes" no LED display on power up

2014-02-08 by <philmurr@...>

Have you checked the pins of the "unlit" LED's with a logic probe - there should be no signal when unlit (of course :-)). Then work back from there to see where there is a signal. Not as straightforward as it sounds because the displays are multiplexed, but you should get an idea of where the problem lies.

I'll assume the PIA is working as other functions are ok, so check IC6, IC9 and IC10, plus transistors T1-T7, but from what you describe I'm going to guess at a problem with the output of IC10 reaching the LED display.

On mine, all IC's are socketed so hopefully yours are too ?

RE: [Simmons Drums] RE: SDS7 question... "sometimes" no LED display on power up

2014-02-10 by <music@...>

Yes, thankfully they are socketed.. it’s a later model SDS7 with the black card slots on the backplane. As far as I can tell all other functions seem normal. I am running the standard 5 card configuration (Bass, Snare, Tom Tom Tom).. but will try cards in all other slots to ensure proper operation…

I did notice that the Data Knob on this particular unit spins very easily and is susceptible to vibration causing unwanted program or value changes… any tips on how to maybe tighten it up a bit?

I’ll be diving in to it this week… fun fun fun… J

Alan

From: Simmons_Drums@yahoogroups.com [mailto:Simmons_Drums@yahoogroups.com] On Behalf Of philmurr@...
Sent: Saturday, February 08, 2014 7:53 AM
To: Simmons_Drums@yahoogroups.com
Subject: [Simmons Drums] RE: SDS7 question... "sometimes" no LED display on power up

Have you checked the pins of the "unlit" LED's with a logic probe - there should be no signal when unlit (of course :-)). Then work back from there to see where there is a signal. Not as straightforward as it sounds because the displays are multiplexed, but you should get an idea of where the problem lies.

I'll assume the PIA is working as other functions are ok, so check IC6, IC9 and IC10, plus transistors T1-T7, but from what you describe I'm going to guess at a problem with the output of IC10 reaching the LED display.

On mine, all IC's are socketed so hopefully yours are too ?

Re: [Simmons Drums] RE: SDS7 question... "sometimes" no LED display on power up

2014-02-10 by Nick Zampiello

sometimes it's as easy as adding a small bit of sticky foam to the underside of a knob to add some friction and keep it from jostling.

z

NEW ALLIANCE EAST!!!!

--------------------------------------

New Alliance East - Mastering

New Alliance East - Facebook
X :::: B :::: S

On Monday, February 10, 2014 12:04 PM, "music@..." <music@...> wrote:

Yes, thankfully they are socketed.. it’s a later model SDS7 with the black card slots on the backplane. As far as I can tell all other functions seem normal. I am running the standard 5 card configuration (Bass, Snare, Tom Tom Tom).. but will try cards in all other slots to ensure proper operation…

I did notice that the Data Knob on this particular unit spins very easily and is susceptible to vibration causing unwanted program or value changes… any tips on how to maybe tighten it up a bit?

I’ll be diving in to it this week… fun fun fun… J

Alan

From: Simmons_Drums@yahoogroups.com [mailto:Simmons_Drums@yahoogroups.com] On Behalf Of philmurr@...
Sent: Saturday, February 08, 2014 7:53 AM
To: Simmons_Drums@yahoogroups.com
Subject: [Simmons Drums] RE: SDS7 question... "sometimes" no LED display on power up

Have you checked the pins of the "unlit" LED's with a logic probe - there should be no signal when unlit (of course :-)). Then work back from there to see where there is a signal. Not as straightforward as it sounds because the displays are multiplexed, but you should get an idea of where the problem lies.

I'll assume the PIA is working as other functions are ok, so check IC6, IC9 and IC10, plus transistors T1-T7, but from what you describe I'm going to guess at a problem with the output of IC10 reaching the LED display.

On mine, all IC's are socketed so hopefully yours are too ?

RE: [Simmons Drums] RE: SDS7 question... "sometimes" no LED display on power up

2014-02-10 by <music@...>

I was entertaining the idea of dismantling the knob assembly and sliding a small nylon washer onto the shaft to take up any gap space… but I like your idea better J.

Cheers

A

From: Simmons_Drums@yahoogroups.com [mailto:Simmons_Drums@yahoogroups.com] On Behalf Of Nick Zampiello
Sent: Monday, February 10, 2014 11:10 AM
To: Simmons_Drums@yahoogroups.com
Subject: Re: [Simmons Drums] RE: SDS7 question... "sometimes" no LED display on power up

sometimes it's as easy as adding a small bit of sticky foam to the underside of a knob to add some friction and keep it from jostling.

z

NEW ALLIANCE EAST!!!!

--------------------------------------

New Alliance East - Mastering

New Alliance East - Facebook X :::: B :::: S

On Monday, February 10, 2014 12:04 PM, "music@..." <music@...> wrote:

Yes, thankfully they are socketed.. it’s a later model SDS7 with the black card slots on the backplane. As far as I can tell all other functions seem normal. I am running the standard 5 card configuration (Bass, Snare, Tom Tom Tom).. but will try cards in all other slots to ensure proper operation…

I did notice that the Data Knob on this particular unit spins very easily and is susceptible to vibration causing unwanted program or value changes… any tips on how to maybe tighten it up a bit?

I’ll be diving in to it this week… fun fun fun… J

Alan

From: Simmons_Drums@yahoogroups.com [mailto:Simmons_Drums@yahoogroups.com] On Behalf Of philmurr@...
Sent: Saturday, February 08, 2014 7:53 AM
To: Simmons_Drums@yahoogroups.com
Subject: [Simmons Drums] RE: SDS7 question... "sometimes" no LED display on power up

Have you checked the pins of the "unlit" LED's with a logic probe - there should be no signal when unlit (of course :-)). Then work back from there to see where there is a signal. Not as straightforward as it sounds because the displays are multiplexed, but you should get an idea of where the problem lies.

I'll assume the PIA is working as other functions are ok, so check IC6, IC9 and IC10, plus transistors T1-T7, but from what you describe I'm going to guess at a problem with the output of IC10 reaching the LED display.

On mine, all IC's are socketed so hopefully yours are too ?

RE: [Simmons Drums] RE: SDS7 question... "sometimes" no LED display on power up

2014-02-11 by <warlandr63@...>

Just wanted to concur that if the KIT display is not functioning AND all connections, pcb tracks pertaining to it are all ok, it will be either IC9 (74LS164 - display data serial to parallel latch) or more likely IC10 (ULN2002 - digit drivers) It is remotely possible that the outputs from IC14 (pins39 - serial clock or 19 - serial data) "could" be at fault or tracks damages, dry joints etc. It is unlikely though as the other functions handled by this IC appear from what you say to be working.

RE: [Simmons Drums] RE: SDS7 question... "sometimes" no LED display on power up

2014-02-11 by <music@...>

Great, thanks Richard.

Now to find good quality time to actually do this thing!!

Alan

From: Simmons_Drums@yahoogroups.com [mailto:Simmons_Drums@yahoogroups.com] On Behalf Of warlandr63@...
Sent: Tuesday, February 11, 2014 6:50 AM
To: Simmons_Drums@yahoogroups.com
Subject: RE: [Simmons Drums] RE: SDS7 question... "sometimes" no LED display on power up

Just wanted to concur that if the KIT display is not functioning AND all connections, pcb tracks pertaining to it are all ok, it will be either IC9 (74LS164 - display data serial to parallel latch) or more likely IC10 (ULN2002 - digit drivers) It is remotely possible that the outputs from IC14 (pins39 - serial clock or 19 - serial data) "could" be at fault or tracks damages, dry joints etc. It is unlikely though as the other functions handled by this IC appear from what you say to be working.

Re: [Simmons Drums] RE: SDS7 question... "sometimes" no LED display on power up

2014-02-12 by Nick Zampiello

i've used rubber washers from the hardware store as well.

they work too! but i like the sticky art foam because it feels so macgyver!

NEW ALLIANCE EAST!!!!

--------------------------------------

New Alliance East - Mastering

New Alliance East - Facebook
X :::: B :::: S

On Wednesday, February 12, 2014 3:11 AM, "music@..." <music@...> wrote:

Great, thanks Richard.

Now to find good quality time to actually do this thing!!

Alan

From: Simmons_Drums@yahoogroups.com [mailto:Simmons_Drums@yahoogroups.com] On Behalf Of warlandr63@...
Sent: Tuesday, February 11, 2014 6:50 AM
To: Simmons_Drums@yahoogroups.com
Subject: RE: [Simmons Drums] RE: SDS7 question... "sometimes" no LED display on power up

Just wanted to concur that if the KIT display is not functioning AND all connections, pcb tracks pertaining to it are all ok, it will be either IC9 (74LS164 - display data serial to parallel latch) or more likely IC10 (ULN2002 - digit drivers) It is remotely possible that the outputs from IC14 (pins39 - serial clock or 19 - serial data) "could" be at fault or tracks damages, dry joints etc. It is unlikely though as the other functions handled by this IC appear from what you say to be working.