Jump to content



Recommended Posts

I bought a vectrex with the image not filling the screen. Cranking up the x y pots enlarge the image to the point shown in the screenshot. 

The image went normal after performing zero dac procedure on IC304 (with oscilloscope) after thinkering at least 3 hours. The image enlarged when I triggered the signal.

The image remained ok for some time, the console was off for almost a week and when I checked again the image was shrunk again. So I performed the same tricks, the image expanded again, I cleaned and deoxidized the legs of IC304.


The image was good for another week than after a period of non use the image was small again. 


Reseated and cleaned all the components, cleaned the whole logic pcb, than I proceeded with zeroing the DAC (but was ok indeed) and doing the other screen calibrations. I swapped the opa IC304 with a new one but the image didn't change.


Now the image is shrunk all the time.


Do you have any suggestion? I was thinking of recapping the boards, even if there are no signs of corrosion.


thank you



Link to comment
Share on other sites

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.

Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Recently Browsing   0 members

    • No registered users viewing this page.
  • Create New...