Help with vectrex graphics issue

[xxdrjewxx]

Problem with graphics on the vectrex. I've search a lot and cannot find how to repair the issue, i found a thread on this page from someone  who had the exact problem, he said he finally fixed it by changing a chip, cant remember the name but i cannot fond any chip with the same name on the vectrex and no mention of it in another forum or web page. When i turn on the vectrex it displays fine, the vectrex name comes up but then after like 5 seconds the letters become just lines, then the game starts and you can see parts of the game but a whole lot of lines coming out from the center of the screen. See the pictures attached. I am no expert on electronics, i opened it up and cant see any capacitors leaking or any cables out of place or rust anywhere. Please help if you have any trouble like mine and how did you fix it.

(I already adjusted the knob on the brightness and it didnt do anything).

Edited January 26, 2021 by xxdrjewxx

[+KylJoy]

That issue does bring IC issue to mind for me.  Do you have someone local with a working unit that would allow you to CAREFULLY and SAFELY swap ICs?  You could at least try the socketed ICs.

 

These things can be terrible to work on.  I worked on one for many, many hours over the course of two years (not the whole time...) and never could get the issue resolved.  Others, not too horrible.  These things weren't really built to last as long as we've loved them.

[xxdrjewxx]

20 hours ago, KylJoy said:

That issue does bring IC issue to mind for me.  Do you have someone local with a working unit that would allow you to CAREFULLY and SAFELY swap ICs?  You could at least try the socketed ICs.

 

These things can be terrible to work on.  I worked on one for many, many hours over the course of two years (not the whole time...) and never could get the issue resolved.  Others, not too horrible.  These things weren't really built to last as long as we've loved them.

Ive looked into the IC and i found several chip problems that could be the problem but do you have a specifoc IC you where thinking about? Caise i dont have a clue and it seems that there are no replacement for them except for another vectrex as you said. Any input you could offer?

[Yoruk]

Your pictures shows that there is an issue with the Z display axis (the ability of the CRT to "turn on" and "off" the light spot.)

 

If you are familiar with electronics and if you are aware of the dangerousness of the high voltages inside the Vectrex, the first thing to do should be to test the video outputs of the main logical board (I mean, before the CRT/power board) with a scope, just to locate the problem :on the logical board, or on the CRT power board ?

Edited July 23, 2021 by Yoruk