shear_xear Posted March 27, 2018 Share Posted March 27, 2018 Hi everyone. I have a Vectrex that I am trying to bring back from the dead. I am getting close with the picture and balancing the pots and yoke, but I still have no audio. The hum is back, but just none of the sound. I have disconnected and reconnected the cable connecting the two boards and cleaned and reset the sound ic. Any ideas on what to look at next? Thanks! Quote Link to comment Share on other sites More sharing options...
R.Cade Posted March 27, 2018 Share Posted March 27, 2018 You'll just have to trace it backwards in the circuit with a scope until you see audio. Without a scope and only "shotgun" approach you are limited to just guessing. I would probably start with the volume pot first, then the audio chip. Quote Link to comment Share on other sites More sharing options...
SignGuy81 Posted March 27, 2018 Share Posted March 27, 2018 Could be the lm386 op amp too IC103 Quote Link to comment Share on other sites More sharing options...
shear_xear Posted March 27, 2018 Author Share Posted March 27, 2018 So the amp can cause the hum and still possibly be bad? Quote Link to comment Share on other sites More sharing options...
SignGuy81 Posted March 27, 2018 Share Posted March 27, 2018 (edited) Probably not it is probably before the amp I'm sure, I kinda overlooked your title and part of the post. Edited March 27, 2018 by SignGuy81 Quote Link to comment Share on other sites More sharing options...
shear_xear Posted March 27, 2018 Author Share Posted March 27, 2018 Ok. I was hoping that if I had the hum the amp was still working. Quote Link to comment Share on other sites More sharing options...
SignGuy81 Posted March 27, 2018 Share Posted March 27, 2018 How does C323 look? Quote Link to comment Share on other sites More sharing options...
shear_xear Posted March 27, 2018 Author Share Posted March 27, 2018 R.Cade, when you say the volume pot are you referring to the power/volume potentiometer? Quote Link to comment Share on other sites More sharing options...
shear_xear Posted March 27, 2018 Author Share Posted March 27, 2018 R.Cade, when you say the volume pot are you referring to the power/volume potentiometer? Quote Link to comment Share on other sites More sharing options...
SignGuy81 Posted March 27, 2018 Share Posted March 27, 2018 R326 is what he is referring to I believe. The 10k ohm volume pot. Quote Link to comment Share on other sites More sharing options...
SignGuy81 Posted March 27, 2018 Share Posted March 27, 2018 Looking at the schematic if that cap has gone bad(C323) that could be causing the issue. Quote Link to comment Share on other sites More sharing options...
shear_xear Posted March 27, 2018 Author Share Posted March 27, 2018 Ill check it, but I recapped everything as my first step so hopefully its not that. Quote Link to comment Share on other sites More sharing options...
SignGuy81 Posted March 28, 2018 Share Posted March 28, 2018 That pot you was talking about earlier is the correct one. Quote Link to comment Share on other sites More sharing options...
Like us on Facebook
Follow us on Twitter
AtariAge on Instagram
Watch us on YouTube
Chat on Discord
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.