electro-music.com   Dedicated to experimental electro-acoustic
and electronic music
 
    Front Page  |  Articles  |  Radio
 |  Media  |  Forum  |  Wiki  |  Links  |  Store
Forum with support of Syndicator RSS
 FAQFAQ   CalendarCalendar   SearchSearch   MemberlistMemberlist   UsergroupsUsergroups   LinksLinks
 RegisterRegister   ProfileProfile   Log in to check your private messagesLog in to check your private messages   Log inLog in  Chat RoomChat Room 
Live streaming at radio.electro-music.com

  host / artist show at your time
  Faux Pas Quartet and friends Music From Last Thursday
Please visit the chat
 Forum index » DIY Hardware and Software » The Repair Shop
Help with a partially working SH-09 ADSR
Post new topic   Reply to topic
Page 1 of 1 [1 Post]
View unread posts
View new posts in the last week
Mark the topic unread :: View previous topic :: View next topic
Author Message
GNSDG



Joined: Aug 27, 2013
Posts: 1
Location: NJ

PostPosted: Tue Aug 27, 2013 6:25 am    Post subject: Help with a partially working SH-09 ADSR Reply with quote  Mark this post and the followings unread

Hey all--first post, here! Not sure I'm putting this in the correct spot, but the short is that my SH-09's sustain slider is not functioning. It had been spotty for a long time before I began a suite of mods to the synth to give me modular-like access to the SH-09's guts, and actually it was functioning perfectly for a while during that process. Now, however, it's not working at all. It's as if the slider is at full sustain regardless of it's position.

Given the symptom, I checked that the connection to ground at the bottom of the pot is solid. It is. Then I checked that the actual resistance between wiper and end was changing correctly, and it does seem to be. So, now the trail runs a bit cold for me.

Here's a link to the service manual, which has the full schematic:
http://manuals.fdiskc.com/flat/Roland%20SH09%20Service%20Manual.pdf

What I'm wondering now is if it's possible I accidentally shorted drain to gate or something for one of the transistors Q26-Q28 somewhere along the line. This doesn't seem likely to me because the problem had manifest itself years before I started the mods, but who knows?

So, of course any insight you guys have is very, very much appreciated. Specifically, I'm wondering if you can tell me how I might test for problems in the functioning of those transistors. (I wouldn't mind just replacing them, but of course C1740s and A826s are not in plentiful supply these days, and my SS chops are weak I'd be hesitant to pick replacements.)

Thanks, gentleman.
Back to top
View user's profile Send private message
Display posts from previous:   
Post new topic   Reply to topic
Page 1 of 1 [1 Post]
View unread posts
View new posts in the last week
Mark the topic unread :: View previous topic :: View next topic
 Forum index » DIY Hardware and Software » The Repair Shop
Jump to:  

You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
You cannot attach files in this forum
You can download files in this forum
e-m mkii

Please support our site. If you click through and buy from
our affiliate partners, we earn a small commission.


Forum with support of Syndicator RSS
Powered by phpBB © 2001, 2005 phpBB Group
Copyright © 2003 through 2009 by electro-music.com - Conditions Of Use