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CGS82 Negative Slew

CGS82 Negative Slew

2013-10-03 by Stephen Richards

Hi Ken and All

I finished building the CGS82 Negative Slew. Had i 'working' , as far as i can understand it so far , but the bottom section LED was not working.

While i was trying to troubleshoot that problem , i noticed i had omitted the link that's between the RATE pads on the PCB and the 22K trimmer.

When i put that link in , every thing seems to have stopped working and the BC547 in the 6V section directly above the 6.8K resistor is getting very hot under power.

Should i replace the BC547 , not too sure how to proceed.

Re: CGS82 Negative Slew

2013-10-04 by cg_synth

First, find where the short circuit is! The transistor should not get hot.


Ken

Show quoted textHide quoted text
---In cgs_synth@yahoogroups.com, <cgs_synth@yahoogroups.com> wrote:

Hi Ken and All

I finished building the CGS82 Negative Slew. Had i 'working' , as far as i can understand it so far , but the bottom section LED was not working.

While i was trying to troubleshoot that problem , i noticed i had omitted the link that's between the RATE pads on the PCB and the 22K trimmer.

When i put that link in , every thing seems to have stopped working and the BC547 in the 6V section directly above the 6.8K resistor is getting very hot under power.

Should i replace the BC547 , not too sure how to proceed.

Re: CGS82 Negative Slew

2013-10-05 by Stephen Richards

Thanks Ken

I've been looking for a short , will keep looking.

Any clue on why it works without that link installed ? Could that be the key to tracking down this problem ?

Show quoted textHide quoted text
From: "sasami@..." <sasami@...>
To: cgs_synth@yahoogroups.com
Sent: Saturday, October 5, 2013 9:21 AM
Subject: [cgs_synth] RE: CGS82 Negative Slew

First, find where the short circuit is! The transistor should not get hot.

Ken


---In cgs_synth@yahoogroups.com, <cgs_synth@yahoogroups.com> wrote:

Hi Ken and All

I finished building the CGS82 Negative Slew. Had i 'working' , as far as i can understand it so far , but the bottom section LED was not working.

While i was trying to troubleshoot that problem , i noticed i had omitted the link that's between the RATE pads on the PCB and the 22K trimmer.

When i put that link in , every thing seems to have stopped working and the BC547 in the 6V section directly above the 6.8K resistor is getting very hot under power.

Should i replace the BC547 , not too sure how to proceed.


Re: CGS82 Negative Slew

2013-10-05 by cg_synth

The links are all part of the 0V power rail. with any of them missing, nothing was working properly.



---In cgs_synth@yahoogroups.com, <cgs_synth@yahoogroups.com> wrote:

Thanks Ken

I've been looking for a short , will keep looking.

Any clue on why it works without that link installed ? Could that be the key to tracking down this problem ?

Show quoted textHide quoted text
From: "sasami@..." <sasami@...>
To: cgs_synth@yahoogroups.com
Sent: Saturday, October 5, 2013 9:21 AM
Subject: [cgs_synth] RE: CGS82 Negative Slew

First, find where the short circuit is! The transistor should not get hot.

Ken


---In cgs_synth@yahoogroups.com, <cgs_synth@yahoogroups.com> wrote:

Hi Ken and All

I finished building the CGS82 Negative Slew. Had i 'working' , as far as i can understand it so far , but the bottom section LED was not working.

While i was trying to troubleshoot that problem , i noticed i had omitted the link that's between the RATE pads on the PCB and the 22K trimmer.

When i put that link in , every thing seems to have stopped working and the BC547 in the 6V section directly above the 6.8K resistor is getting very hot under power.

Should i replace the BC547 , not too sure how to proceed.


Re: CGS82 Negative Slew

2013-10-05 by Stephen Richards

OK thanks , i can't find a short. I'm stumped.I'll keep plugging away at it.

Show quoted textHide quoted text
From: "sasami@..." <sasami@...>
To: cgs_synth@yahoogroups.com
Sent: Saturday, October 5, 2013 12:13 PM
Subject: RE: Re: [cgs_synth] RE: CGS82 Negative Slew

The links are all part of the 0V power rail. with any of them missing, nothing was working properly.


---In cgs_synth@yahoogroups.com, <cgs_synth@yahoogroups.com> wrote:

Thanks Ken

I've been looking for a short , will keep looking.

Any clue on why it works without that link installed ? Could that be the key to tracking down this problem ?

From: "sasami@..." <sasami@...>
To: cgs_synth@yahoogroups.com
Sent: Saturday, October 5, 2013 9:21 AM
Subject: [cgs_synth] RE: CGS82 Negative Slew

First, find where the short circuit is! The transistor should not get hot.

Ken


---In cgs_synth@yahoogroups.com, <cgs_synth@yahoogroups.com> wrote:

Hi Ken and All

I finished building the CGS82 Negative Slew. Had i 'working' , as far as i can understand it so far , but the bottom section LED was not working.

While i was trying to troubleshoot that problem , i noticed i had omitted the link that's between the RATE pads on the PCB and the 22K trimmer.

When i put that link in , every thing seems to have stopped working and the BC547 in the 6V section directly above the 6.8K resistor is getting very hot under power.

Should i replace the BC547 , not too sure how to proceed.




Re: CGS82 Negative Slew

2013-10-06 by Stephen Richards

Hi Ken

When the PCB is powered up , if i put my finger on the BC547 in the the 6V section. It is cool to the touch for a few seconds then becomes very hot very quickly.

I have changed out all of the electrolytics and there is no change , i have looked over and over and can't find a short.

Now that the electros in the power filtering are changed , should i put another BC547 in ?

I'm racking my brain but can't find a solution.

Show quoted textHide quoted text
From: "sasami@..." <sasami@...>
To: cgs_synth@yahoogroups.com
Sent: Saturday, October 5, 2013 12:13 PM
Subject: RE: Re: [cgs_synth] RE: CGS82 Negative Slew

The links are all part of the 0V power rail. with any of them missing, nothing was working properly.


---In cgs_synth@yahoogroups.com, <cgs_synth@yahoogroups.com> wrote:

Thanks Ken

I've been looking for a short , will keep looking.

Any clue on why it works without that link installed ? Could that be the key to tracking down this problem ?

From: "sasami@..." <sasami@...>
To: cgs_synth@yahoogroups.com
Sent: Saturday, October 5, 2013 9:21 AM
Subject: [cgs_synth] RE: CGS82 Negative Slew

First, find where the short circuit is! The transistor should not get hot.

Ken


---In cgs_synth@yahoogroups.com, <cgs_synth@yahoogroups.com> wrote:

Hi Ken and All

I finished building the CGS82 Negative Slew. Had i 'working' , as far as i can understand it so far , but the bottom section LED was not working.

While i was trying to troubleshoot that problem , i noticed i had omitted the link that's between the RATE pads on the PCB and the 22K trimmer.

When i put that link in , every thing seems to have stopped working and the BC547 in the 6V section directly above the 6.8K resistor is getting very hot under power.

Should i replace the BC547 , not too sure how to proceed.




Re: CGS82 Negative Slew

2013-10-07 by cg_synth

Find out what voltage is on the "6V" line - it's probably less than 6V.
Start isolating bits of the circuit to find out what is causing the massive
current drain - power rail will return to 6V when the affected circuit is
disconnected. Try pulling out the chips to start with. I assume they are in
sockets.
Replace the BC547, but expect the next one to behave in exactly the same way
until the fault is found.

Ken
Show quoted textHide quoted text
>Hi Ken
>
>When the PCB is powered up , if i put my finger on the BC547 in the the 6V
section. It is cool to the touch for a few seconds then becomes very hot
very quickly.
>
>I have changed out all of the electrolytics and there is no change , i have
looked over and over and can't find a short.
>
>Now that the electros in the power filtering are changed , should i put
another BC547 in ?
>
>I'm racking my brain but can't find a solution.
>
>
>________________________________
> From: "sasami@..." <sasami@...>
>To: cgs_synth@yahoogroups.com
>Sent: Saturday, October 5, 2013 12:13 PM
>Subject: RE: Re: [cgs_synth] RE: CGS82 Negative Slew
>
>
>
>Â
>The links are all part of the 0V power rail. with any of them missing,
nothing was working properly.
>
>
>
>---In cgs_synth@yahoogroups.com, <cgs_synth@yahoogroups.com> wrote:
>
>
>Thanks Ken
>
>I've been looking for a short , will keep looking.
>
>Any clue on why it works without that link installed ? Could that be the
key to tracking down this problem ?
>
>
>________________________________
> From: "sasami@..." <sasami@...>
>To: cgs_synth@yahoogroups.com
>Sent: Saturday, October 5, 2013 9:21 AM
>Subject: [cgs_synth] RE: CGS82 Negative Slew
>
>
>
>Â
>First, find where the short circuit is! The transistor should not get hot.
>
>Ken
>
>
>
>---In cgs_synth@yahoogroups.com, <cgs_synth@yahoogroups.com> wrote:
>
>
>Hi Ken and All
>
>I finished building the CGS82 Negative Slew. Had i 'working' , as far as i
can understand it so far , but the bottom section LED was not working.
>
>While i was trying to troubleshoot that problem , i noticed i had omitted
the link that's between the RATE pads on the PCB and the 22K trimmer.
>
>When i put that link in , every thing seems to have stopped working and the
BC547 in the 6V section directly above the 6.8K resistor is getting very hot
under power.
>
>Should i replace the BC547 , not too sure how to proceed.
>
>
>
>
>
>
><head>
>
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><!-- |**|begin egp html banner|**| -->
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>
><div style="color:#000; background-color:#fff; font-family:tahoma, new
york, times, serif;font-size:10pt"><div style="margin-top: 0px;
margin-right: 0px; margin-bottom: 0px; margin-left: 0px; color: rgb(0, 0,
0); font-size: 13px; font-family: tahoma, 'new york', times, serif;
background-color: transparent; font-style: normal; "><span>Hi
Ken</span></div><div style="margin-top: 0px; margin-right: 0px;
margin-bottom: 0px; margin-left: 0px; color: rgb(0, 0, 0); font-size: 13px;
font-family: tahoma, 'new york', times, serif; background-color:
transparent; font-style: normal; "><span><br></span></div><div
style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left:
0px; color: rgb(0, 0, 0); font-size: 13px; font-family: tahoma, 'new york',
times, serif; background-color: transparent; font-style: normal;
"><span>When the PCB is powered up , if i put my finger on the BC547 in the
the 6V section. It is cool to the touch for a few
> seconds then becomes very hot very quickly.</span></div><div
style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left:
0px; color: rgb(0, 0, 0); font-size: 13px; font-family: tahoma, 'new york',
times, serif; background-color: transparent; font-style: normal;
"><span><br></span></div><div><span>I have changed out all of the
electrolytics and there is no change , i have looked over and over and can't
find a short.</span></div><div style="color: rgb(0, 0, 0); font-size: 13px;
font-family: tahoma, 'new york', times, serif; background-color:
transparent; font-style: normal; "><span><br></span></div><div style="color:
rgb(0, 0, 0); font-size: 13px; font-family: tahoma, 'new york', times,
serif; background-color: transparent; font-style: normal; "><span>Now that
the electros in the power filtering are changed , should i put another BC547
in ?</span></div><div style="color: rgb(0, 0, 0); font-size: 13px;
font-family: tahoma, 'new york',
> times, serif; background-color: transparent; font-style: normal;
"><span><br></span></div><div style="color: rgb(0, 0, 0); font-size: 13px;
font-family: tahoma, 'new york', times, serif; background-color:
transparent; font-style: normal; "><span>I'm racking my brain but can't find
a solution.</span></div><div style="color: rgb(0, 0, 0); font-size: 13px;
font-family: tahoma, 'new york', times, serif; background-color:
transparent; font-style: normal; "><br></div> <div style="font-size: 10pt;
font-family: tahoma, 'new york', times, serif; "> <div style="font-size:
12pt; font-family: 'times new roman', 'new york', times, serif; "> <div
dir="ltr"> <hr size="1"> <font size="2" face="Arial"> <b><span
style="font-weight:bold;">From:</span></b> "sasami@..."
<sasami@...><br> <b><span style="font-weight:
bold;">To:</span></b> cgs_synth@yahoogroups.com <br> <b><span
style="font-weight: bold;">Sent:</span></b> Saturday, October 5, 2013
> 12:13 PM<br> <b><span style="font-weight: bold;">Subject:</span></b> RE:
Re: [cgs_synth] RE: CGS82 Negative Slew<br> </font> </div> <div
class="y_msg_container"><br><div id="yiv7783768150"><div>
><span style="display:none;"> </span>
>
>
><div id="yiv7783768150ygrp-mlmsg" style="">
> <div id="yiv7783768150ygrp-msg" style="">
>
>
> <div id="yiv7783768150ygrp-text">
>
>
> <div>The links are all part of the 0V power rail. with any of them
missing, nothing was working properly. <br clear="none"></div> <div
class="yiv7783768150yqt6770454614" id="yiv7783768150yqt52476"><div
class="yiv7783768150ygroups-quoted"><br clear="none"><br clear="none">---In
cgs_synth@yahoogroups.com, <cgs_synth@yahoogroups.com> wrote:<br
clear="none"><br clear="none"><div
id="yiv7783768150ygrps-yiv-920038537"><div style="color: rgb(0, 0, 0);
background-color: rgb(255, 255, 255); font-size: 10pt; font-family: tahoma,
'new york', times, serif; "><div><span>Thanks Ken</span></div><div
style="color: rgb(0, 0, 0); font-size: 13px; background-color: transparent;
font-style: normal; font-family: tahoma, 'new york', times, serif;
"><span><br clear="none"></span></div><div style="color: rgb(0, 0, 0);
font-size: 13px; background-color: transparent; font-style: normal;
font-family: tahoma, 'new york', times, serif; "><span>I've been looking for a
> short , will keep looking.</span></div><div style="color: rgb(0, 0, 0);
font-size: 13px; background-color: transparent; font-style: normal;
font-family: tahoma, 'new york', times, serif; "><span><br
clear="none"></span></div><div style="color: rgb(0, 0, 0); font-size: 13px;
background-color: transparent; font-style: normal; font-family: tahoma, 'new
york', times, serif; "><span>Any clue on why it works without that link
installed ? Could that be the key to tracking down
> this problem ?</span></div><div><br clear="none"></div> <div
style="font-size: 10pt; font-family: tahoma, 'new york', times, serif; ">
<div style="font-size: 12pt; font-family: 'times new roman', 'new york',
times, serif; "> <div dir="ltr"> <hr size="1"> <font size="2" face="Arial">
<b><span style="font-weight:bold;">From:</span></b> "sasami@..."
<sasami@...><br clear="none"> <b><span
style="font-weight:bold;">To:</span></b> cgs_synth@yahoogroups.com <br
clear="none"> <b><span style="font-weight:bold;">Sent:</span></b> Saturday,
October 5, 2013 9:21 AM<br clear="none"> <b><span
style="font-weight:bold;">Subject:</span></b> [cgs_synth] RE: CGS82 Negative
Slew<br clear="none"> </font> </div> <div
class="yiv7783768150ygrps-yiv-920038537y_msg_container"><br
clear="none"><div id="yiv7783768150ygrps-yiv-920038537yiv0802677040"><div>
><span> </span>
>
>
><div id="yiv7783768150ygrps-yiv-920038537yiv0802677040ygrp-mlmsg">
> <div id="yiv7783768150ygrps-yiv-920038537yiv0802677040ygrp-msg">
>
>
> <div id="yiv7783768150ygrps-yiv-920038537yiv0802677040ygrp-text">
>
>
> <div>First, find where the short circuit is! The transistor
should not get hot.</div><div><br clear="none"></div><div style="color:
rgb(0, 0, 0); font-size: 13px; background-color: transparent; font-style:
normal; font-family: arial, helvetica, clean, sans-serif; ">Ken<br
clear="none"></div> <div
class="yiv7783768150ygrps-yiv-920038537yiv0802677040yqt4146213120"
id="yiv7783768150ygrps-yiv-920038537yiv0802677040yqt98838"><div
class="yiv7783768150ygrps-yiv-920038537yiv0802677040ygroups-quoted"><br
clear="none"><br clear="none">---In cgs_synth@yahoogroups.com,
<cgs_synth@yahoogroups.com> wrote:<br clear="none"><br
clear="none"><div
id="yiv7783768150ygrps-yiv-920038537yiv0802677040ygrps-yiv-1760770583"><div
style="color: rgb(0, 0, 0); background-color: rgb(255, 255, 255); font-size:
10pt; font-family: tahoma, 'new york', times, serif; "><div>Hi Ken and
All</div><div><br clear="none"></div><div style="color: rgb(0, 0, 0);
font-size: 13px;
> background-color: transparent; font-style: normal; font-family: tahoma,
'new york', times, serif; ">I finished building the CGS82
> Negative Slew. Had i 'working' , as far as i can understand it so far ,
but the bottom section LED was not working.</div><div style="color: rgb(0,
0, 0); font-size: 13px; background-color: transparent; font-style: normal;
font-family: tahoma, 'new york', times, serif; "><br clear="none"></div><div
style="color: rgb(0, 0, 0); font-size: 13px; background-color: transparent;
font-style: normal; font-family: tahoma, 'new york', times, serif; ">While i
was trying to troubleshoot that problem , i noticed i had omitted the link
that's between the RATE pads on the PCB and the 22K trimmer.</div><div
style="color: rgb(0, 0, 0); font-size: 13px; background-color: transparent;
font-style: normal; font-family: tahoma, 'new york', times, serif; "><br
clear="none"></div><div style="color: rgb(0, 0, 0); font-size: 13px;
background-color: transparent; font-style: normal; font-family: tahoma, 'new
york', times, serif; ">When i put that link in , every thing seems to have
> stopped working and the BC547 in the 6V section directly above the 6.8K
resistor is getting very hot under power.</div><div style="color: rgb(0, 0,
0); font-size: 13px; background-color: transparent; font-style: normal;
font-family: tahoma, 'new york', times, serif; "><br clear="none"></div><div
style="color: rgb(0, 0, 0); font-size: 13px; background-color: transparent;
font-style: normal; font-family: tahoma, 'new york', times, serif; ">Should
i replace the BC547 , not too sure how to proceed.</div></div></div></div></div>
>
> </div>
>
>
>
> <div class="yiv7783768150ygrps-yiv-920038537yiv0802677040yqt4146213120"
id="yiv7783768150ygrps-yiv-920038537yiv0802677040yqt92610"><div
style="color:#fff;height:0;"></div></div>
>
>
></div><div
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id="yiv7783768150ygrps-yiv-920038537yiv0802677040yqt42900"></div></div><br
clear="none"><br clear="none"></div> </div> </div>
</div></div></div></div></div></div>
>
> </div>
>
>
>
> <div class="yiv7783768150yqt6770454614" id="yiv7783768150yqt80765"><div
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>
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_______________________________________________________________________
Ken Stone sasami@... otherunicorn@...
Modular Synth PCBs for sale <http://www.cgs.synth.net/>

Re: CGS82 Negative Slew

2013-10-07 by Stephen Richards

Removed the chips , put them back in one by one starting with the LM3900's , then the CA3046's.

Now it's working !!??

Whatever gremlin was in the works seems to have been evicted.

Maybe cheap IC sockets ? I couldn't get 14pin machined sockets in time for this build. I dunno ; but thanks , Ken.

Show quoted textHide quoted text
From: "sasami@..." <sasami@...>
To: cgs_synth@yahoogroups.com
Sent: Monday, October 7, 2013 1:48 PM
Subject: Re: Re: [cgs_synth] RE: CGS82 Negative Slew

Find out what voltage is on the "6V" line - it's probably less than 6V.
Start isolating bits of the circuit to find out what is causing the massive
current drain - power rail will return to 6V when the affected circuit is
disconnected. Try pulling out the chips to start with. I assume they are in
sockets.
Replace the BC547, but expect the next one to behave in exactly the same way
until the fault is found.

Ken

>Hi Ken
>
>When the PCB is powered up , if i put my finger on the BC547 in the the 6V
section. It is cool to the touch for a few seconds then becomes very hot
very quickly.
>
>I have changed out all of the electrolytics and there is no change , i have
looked over and over and can't find a short.
>
>Now that the electros in the power filtering are changed , should i put
another BC547 in ?
>
>I'm racking my brain but can't find a solution.
>
>
>________________________________
> From: "sasami@..." <sasami@...>
>To: cgs_synth@yahoogroups.com
>Sent: Saturday, October 5, 2013 12:13 PM
>Subject: RE: Re: [cgs_synth] RE: CGS82 Negative Slew
>
>
>
>Â
>The links are all part of the 0V power rail. with any of them missing,
nothing was working properly.
>
>
>
>---In cgs_synth@yahoogroups.com, <cgs_synth@yahoogroups.com> wrote:
>
>
>Thanks Ken
>
>I've been looking for a short , will keep looking.
>
>Any clue on why it works without that link installed ? Could that be the
key to tracking down this problem ?
>
>
>________________________________
> From: "sasami@..." <sasami@...>
>To: cgs_synth@yahoogroups.com
>Sent: Saturday, October 5, 2013 9:21 AM
>Subject: [cgs_synth] RE: CGS82 Negative Slew
>
>
>
>Â
>First, find where the short circuit is! The transistor should not get hot.
>
>Ken
>
>
>
>---In cgs_synth@yahoogroups.com, <cgs_synth@yahoogroups.com> wrote:
>
>
>Hi Ken and All
>
>I finished building the CGS82 Negative Slew. Had i 'working' , as far as i
can understand it so far , but the bottom section LED was not working.
>
>While i was trying to troubleshoot that problem , i noticed i had omitted
the link that's between the RATE pads on the PCB and the 22K trimmer.
>
>When i put that link in , every thing seems to have stopped working and the
BC547 in the 6V section directly above the 6.8K resistor is getting very hot
under power.
>
>Should i replace the BC547 , not too sure how to proceed.
>
>
>
>
>
>
><head>
>
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>
><div style="color:#000; background-color:#fff; font-family:tahoma, new
york, times, serif;font-size:10pt"><div style="margin-top: 0px;
margin-right: 0px; margin-bottom: 0px; margin-left: 0px; color: rgb(0, 0,
0); font-size: 13px; font-family: tahoma, 'new york', times, serif;
background-color: transparent; font-style: normal; "><span>Hi
Ken</span></div><div style="margin-top: 0px; margin-right: 0px;
margin-bottom: 0px; margin-left: 0px; color: rgb(0, 0, 0); font-size: 13px;
font-family: tahoma, 'new york', times, serif; background-color:
transparent; font-style: normal; "><span><br></span></div><div
style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left:
0px; color: rgb(0, 0, 0); font-size: 13px; font-family: tahoma, 'new york',
times, serif; background-color: transparent; font-style: normal;
"><span>When the PCB is powered up , if i put my finger on the BC547 in the
the 6V section. It is cool to the touch for a few
> seconds then becomes very hot very quickly.</span></div><div
style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left:
0px; color: rgb(0, 0, 0); font-size: 13px; font-family: tahoma, 'new york',
times, serif; background-color: transparent; font-style: normal;
"><span><br></span></div><div><span>I have changed out all of the
electrolytics and there is no change , i have looked over and over and can't
find a short.</span></div><div style="color: rgb(0, 0, 0); font-size: 13px;
font-family: tahoma, 'new york', times, serif; background-color:
transparent; font-style: normal; "><span><br></span></div><div style="color:
rgb(0, 0, 0); font-size: 13px; font-family: tahoma, 'new york', times,
serif; background-color: transparent; font-style: normal; "><span>Now that
the electros in the power filtering are changed , should i put another BC547
in ?</span></div><div style="color: rgb(0, 0, 0); font-size: 13px;
font-family: tahoma, 'new york',
> times, serif; background-color: transparent; font-style: normal;
"><span><br></span></div><div style="color: rgb(0, 0, 0); font-size: 13px;
font-family: tahoma, 'new york', times, serif; background-color:
transparent; font-style: normal; "><span>I'm racking my brain but can't find
a solution.</span></div><div style="color: rgb(0, 0, 0); font-size: 13px;
font-family: tahoma, 'new york', times, serif; background-color:
transparent; font-style: normal; "><br></div> <div style="font-size: 10pt;
font-family: tahoma, 'new york', times, serif; "> <div style="font-size:
12pt; font-family: 'times new roman', 'new york', times, serif; "> <div
dir="ltr"> <hr size="1"> <font size="2" face="Arial"> <b><span
style="font-weight:bold;">From:</span></b> "sasami@..."
<sasami@...><br> <b><span style="font-weight:
bold;">To:</span></b> cgs_synth@yahoogroups.com <br> <b><span
style="font-weight: bold;">Sent:</span></b> Saturday, October 5, 2013
> 12:13 PM<br> <b><span style="font-weight: bold;">Subject:</span></b> RE:
Re: [cgs_synth] RE: CGS82 Negative Slew<br> </font> </div> <div
class="y_msg_container"><br><div id="yiv7783768150"><div>
><span > </span>
>
>
><div id="yiv7783768150ygrp-mlmsg" style="">
> <div id="yiv7783768150ygrp-msg" style="">
>
>
> <div id="yiv7783768150ygrp-text">
>
>
> <div>The links are all part of the 0V power rail. with any of them
missing, nothing was working properly. <br clear="none"></div> <div
class="yiv7783768150yqt6770454614" id="yiv7783768150yqt52476"><div
class="yiv7783768150ygroups-quoted"><br clear="none"><br clear="none">---In
cgs_synth@yahoogroups.com, <cgs_synth@yahoogroups.com> wrote:<br
clear="none"><br clear="none"><div
id="yiv7783768150ygrps-yiv-920038537"><div style="color: rgb(0, 0, 0);
background-color: rgb(255, 255, 255); font-size: 10pt; font-family: tahoma,
'new york', times, serif; "><div><span>Thanks Ken</span></div><div
style="color: rgb(0, 0, 0); font-size: 13px; background-color: transparent;
font-style: normal; font-family: tahoma, 'new york', times, serif;
"><span><br clear="none"></span></div><div style="color: rgb(0, 0, 0);
font-size: 13px; background-color: transparent; font-style: normal;
font-family: tahoma, 'new york', times, serif; "><span>I've been looking for a
> short , will keep looking.</span></div><div style="color: rgb(0, 0, 0);
font-size: 13px; background-color: transparent; font-style: normal;
font-family: tahoma, 'new york', times, serif; "><span><br
clear="none"></span></div><div style="color: rgb(0, 0, 0); font-size: 13px;
background-color: transparent; font-style: normal; font-family: tahoma, 'new
york', times, serif; "><span>Any clue on why it works without that link
installed ? Could that be the key to tracking down
> this problem ?</span></div><div><br clear="none"></div> <div
style="font-size: 10pt; font-family: tahoma, 'new york', times, serif; ">
<div style="font-size: 12pt; font-family: 'times new roman', 'new york',
times, serif; "> <div dir="ltr"> <hr size="1"> <font size="2" face="Arial">
<b><span style="font-weight:bold;">From:</span></b> "sasami@..."
<sasami@...><br clear="none"> <b><span
style="font-weight:bold;">To:</span></b> cgs_synth@yahoogroups.com <br
clear="none"> <b><span style="font-weight:bold;">Sent:</span></b> Saturday,
October 5, 2013 9:21 AM<br clear="none"> <b><span
style="font-weight:bold;">Subject:</span></b> [cgs_synth] RE: CGS82 Negative
Slew<br clear="none"> </font> </div> <div
class="yiv7783768150ygrps-yiv-920038537y_msg_container"><br
clear="none"><div id="yiv7783768150ygrps-yiv-920038537yiv0802677040"><div>
><span> </span>
>
>
><div id="yiv7783768150ygrps-yiv-920038537yiv0802677040ygrp-mlmsg">
> <div id="yiv7783768150ygrps-yiv-920038537yiv0802677040ygrp-msg">
>
>
> <div id="yiv7783768150ygrps-yiv-920038537yiv0802677040ygrp-text">
>
>
> <div>First, find where the short circuit is! The transistor
should not get hot.</div><div><br clear="none"></div><div style="color:
rgb(0, 0, 0); font-size: 13px; background-color: transparent; font-style:
normal; font-family: arial, helvetica, clean, sans-serif; ">Ken<br
clear="none"></div> <div
class="yiv7783768150ygrps-yiv-920038537yiv0802677040yqt4146213120"
id="yiv7783768150ygrps-yiv-920038537yiv0802677040yqt98838"><div
class="yiv7783768150ygrps-yiv-920038537yiv0802677040ygroups-quoted"><br
clear="none"><br clear="none">---In cgs_synth@yahoogroups.com,
<cgs_synth@yahoogroups.com> wrote:<br clear="none"><br
clear="none"><div
id="yiv7783768150ygrps-yiv-920038537yiv0802677040ygrps-yiv-1760770583"><div
style="color: rgb(0, 0, 0); background-color: rgb(255, 255, 255); font-size:
10pt; font-family: tahoma, 'new york', times, serif; "><div>Hi Ken and
All</div><div><br clear="none"></div><div style="color: rgb(0, 0, 0);
font-size: 13px;
> background-color: transparent; font-style: normal; font-family: tahoma,
'new york', times, serif; ">I finished building the CGS82
> Negative Slew. Had i 'working' , as far as i can understand it so far ,
but the bottom section LED was not working.</div><div style="color: rgb(0,
0, 0); font-size: 13px; background-color: transparent; font-style: normal;
font-family: tahoma, 'new york', times, serif; "><br clear="none"></div><div
style="color: rgb(0, 0, 0); font-size: 13px; background-color: transparent;
font-style: normal; font-family: tahoma, 'new york', times, serif; ">While i
was trying to troubleshoot that problem , i noticed i had omitted the link
that's between the RATE pads on the PCB and the 22K trimmer.</div><div
style="color: rgb(0, 0, 0); font-size: 13px; background-color: transparent;
font-style: normal; font-family: tahoma, 'new york', times, serif; "><br
clear="none"></div><div style="color: rgb(0, 0, 0); font-size: 13px;
background-color: transparent; font-style: normal; font-family: tahoma, 'new
york', times, serif; ">When i put that link in , every thing seems to have
> stopped working and the BC547 in the 6V section directly above the 6.8K
resistor is getting very hot under power.</div><div style="color: rgb(0, 0,
0); font-size: 13px; background-color: transparent; font-style: normal;
font-family: tahoma, 'new york', times, serif; "><br clear="none"></div><div
style="color: rgb(0, 0, 0); font-size: 13px; background-color: transparent;
font-style: normal; font-family: tahoma, 'new york', times, serif; ">Should
i replace the BC547 , not too sure how to proceed.</div></div></div></div></div>
>
> </div>
>
>
>
> <div class="yiv7783768150ygrps-yiv-920038537yiv0802677040yqt4146213120"
id="yiv7783768150ygrps-yiv-920038537yiv0802677040yqt92610"><div
style="color:#fff;height:0;"></div></div>
>
>
></div><div
class="yiv7783768150ygrps-yiv-920038537yiv0802677040yqt4146213120"
id="yiv7783768150ygrps-yiv-920038537yiv0802677040yqt42900"></div></div><br
clear="none"><br clear="none"></div> </div> </div>
</div></div></div></div></div></div>
>
> </div>
>
>
>
> <div class="yiv7783768150yqt6770454614" id="yiv7783768150yqt80765"><div
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__________________________________________________________
Ken Stone sasami@... otherunicorn@...
Modular Synth PCBs for sale <http://www.cgs.synth.net/>



Re: CGS82 Negative Slew

2013-10-07 by cg_synth

Maybe you had a chip in backwards?

Ken

>Removed the chips , put them back in one by one starting with the LM3900's
, then the CA3046's.
>
>Now it's working !!??
>
>Whatever gremlin was in the works seems to have been evicted.
>
>Maybe cheap IC sockets ? I couldn't get 14pin machined sockets in time for
this build. I dunno ; but thanks , Ken.
>
>
_______________________________________________________________________
Ken Stone sasami@... otherunicorn@...
Modular Synth PCBs for sale <http://www.cgs.synth.net/>

Re: CGS82 Negative Slew

2013-10-07 by Richarius Molindarius

Reseating the chips, could also mean a cold solder joint in one of the chip sockets of the PCB. There're too many current drains within that circuit for me to be able to suggest which of the chips that it could have been to be drawing so much current to cause the 547 to over heat.
To possible prevent it from happening again in a future after the PCB has been flexed, in any way - quickly reheat each of the chip's pin / solder pad connections to reflow their solder. That should ensure, that any potentially 'cold' solder joint is connected properly. :) Removing the chips before doing this as well, could be better for the chips. :o
If your soldering iron / tip is 700 degrees, hold the tip to the pin/pad, for approximately 1 second. That should be long enough to reheat the solder, pin and pad.

--
Take care,
Warmth and Peace,
Rich

http://www.damian.deathlehem.com/ - my modular synth
http://www.soundcloud.com/Richarius - my latest composition snippets
http://www.youtube.com/dolphinicus/ - various module videos of mine / etc.

Re: CGS82 Negative Slew

2013-10-07 by Stephen Richards

Thanks Rick

Good advice , will do.

From: Richarius Molindarius <richmolindarius@...>
To: cgs_synth@yahoogroups.com
Sent: Monday, October 7, 2013 10:30 PM
Subject: Re: Re: [cgs_synth] RE: CGS82 Negative Slew

Reseating the chips, could also mean a cold solder joint in one of the chip sockets of the PCB. There're too many current drains within that circuit for me to be able to suggest which of the chips that it could have been to be drawing so much current to cause the 547 to over heat.
To possible prevent it from happening again in a future after the PCB has been flexed, in any way - quickly reheat each of the chip's pin / solder pad connections to reflow their solder. That should ensure, that any potentially 'cold' solder joint is connected properly. :) Removing the chips before doing this as well, could be better for the chips. :o
If your soldering iron / tip is 700 degrees, hold the tip to the pin/pad, for approximately 1 second. That should be long enough to reheat the solder, pin and pad.

--
Take care,
Warmth and Peace,
Rich

http://www.damian.deathlehem.com/ - my modular synth
http://www.soundcloud.com/Richarius - my latest composition snippets
http://www.youtube.com/dolphinicus/ - various module videos of mine / etc.


Re: CGS82 Negative Slew

2013-10-07 by Stephen Richards

Stranger things have happened !

Thanks , Ken.


On 07/10/2013, at 4:17 PM, sasami@... wrote:

Maybe you had a chip in backwards?

Ken

>Removed the chips , put them back in one by one starting with the LM3900's
, then the CA3046's.
>
>Now it's working !!??
>
>Whatever gremlin was in the works seems to have been evicted.
>
>Maybe cheap IC sockets ? I couldn't get 14pin machined sockets in time for
this build. I dunno ; but thanks , Ken.
>
>
__________________________________________________________
Ken Stone sasami@... otherunicorn@...
Modular Synth PCBs for sale <http://www.cgs.synth.net/>

CGS82 Negative Slew

2016-02-08 by gord_harris

CGS82 up and working fine! My second CGS SERGE module built - lots more to go. Thanks Ken for a perfect board and great design with Serge. And thanks to Chris for helping me source the LM3046 from Small Bear Electronics in New York. Next up, CGS79 Ring Modulator I think....

Re: CGS82 Negative Slew

2016-02-08 by Boris Klompus

Awesome! I'll be building the Slews, Ring Mod and more soon. Just need to sell some gear and buy the components. Can't wait!

Are you doing any mods -- loop switch, or exponential control pot?

Boris
Show quoted textHide quoted text
On Mon, Feb 8, 2016 at 11:20 AM, gord@... [cgs_synth] <cgs_synth@yahoogroups.com> wrote:

CGS82 up and working fine! My second CGS SERGE module built - lots more to go. Thanks Ken for a perfect board and great design with Serge. And thanks to Chris for helping me source the LM3046 from Small Bear Electronics in New York. Next up, CGS79 Ring Modulator I think....


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