electro-music.com   Dedicated to experimental electro-acoustic
and electronic music
 
    Front Page  |  Radio
 |  Media  |  Forum  |  Wiki  |  Links
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 
 Forum index » DIY Hardware and Software » YuSynth
need help lfo 2, no light
Post new topic   Reply to topic Moderators: Scott Stites
Page 1 of 1 [7 Posts]
View unread posts
View new posts in the last week
Mark the topic unread :: View previous topic :: View next topic
Author Message
selbersuess



Joined: Mar 21, 2017
Posts: 10
Location: Trier

PostPosted: Tue Mar 21, 2017 3:15 pm    Post subject: need help lfo 2, no light Reply with quote  Mark this post and the followings unread

Hello, i need help with lfo2. module is still working. waves looks ok on my osciilloscope. just the led is not blinking. i checked my pcb, the wires and so on. i cant see differences to yves schematics. i tried another led too. any ideas? thank you
Back to top
View user's profile Send private message Visit poster's website
marfoski



Joined: Jan 26, 2011
Posts: 36
Location: Italy

PostPosted: Tue Mar 21, 2017 11:37 pm    Post subject: Reply with quote  Mark this post and the followings unread

Just a thought: the LED blinking is linked to the rectangular output. If the pulse width is too narrow it can't blink. So you may try to turn clockwise the pulse width knob and see if it makes a difference.
Back to top
View user's profile Send private message
selbersuess



Joined: Mar 21, 2017
Posts: 10
Location: Trier

PostPosted: Wed Mar 22, 2017 4:49 am    Post subject: Reply with quote  Mark this post and the followings unread

ok, thank you. i will check this evening.
Back to top
View user's profile Send private message Visit poster's website
selbersuess



Joined: Mar 21, 2017
Posts: 10
Location: Trier

PostPosted: Wed Mar 22, 2017 11:10 am    Post subject: Reply with quote  Mark this post and the followings unread

i tested, but no light.
i replaced bc547, checked the polarity of the led. curios...
Back to top
View user's profile Send private message Visit poster's website
donpachi



Joined: Jul 16, 2009
Posts: 81
Location: Marburg
Audio files: 2

PostPosted: Thu Mar 23, 2017 11:47 am    Post subject: Reply with quote  Mark this post and the followings unread

I would
-check if Q3 gets 15 V
-check correct values of R33 and R43
-trace the signal from U2 pin 8 towards the LED with the oscilloscope
HTH
Back to top
View user's profile Send private message
selbersuess



Joined: Mar 21, 2017
Posts: 10
Location: Trier

PostPosted: Thu Mar 23, 2017 12:36 pm    Post subject: Reply with quote  Mark this post and the followings unread

sorry, stupid me, i'm ashamed...

it was a little mini-solder-pearl that shorten trace from r43 to q3 to gnd. now the led fires and the waves are looking much better.
i looked at the pcb 100 times with a magnifier and would have bet my family that there is no short.

thank you
Back to top
View user's profile Send private message Visit poster's website
marfoski



Joined: Jan 26, 2011
Posts: 36
Location: Italy

PostPosted: Thu Mar 23, 2017 9:16 pm    Post subject: Reply with quote  Mark this post and the followings unread

Don't worry. It's the fun part of DIY. Laughing
Back to top
View user's profile Send private message
Display posts from previous:   
Post new topic   Reply to topic Moderators: Scott Stites
Page 1 of 1 [7 Posts]
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 » YuSynth
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


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