Vertical band after flyback replacement

[theminidriver]

Hi all,

I've been having some fun ( and frustration!) getting my old Plus working.

You can see the full saga here : https://forums.macrumors.com/threads/mac-plus-power-supply-modifications.2327180/

I needed to replace the flyback as the screen was garbled and some severe burning smells were coming out of the Plus , so I picked up a flyback from 157-026C Flyback 157026C / Replaces Apple / HR 42031 | eBay /

It fixed it a bit - the screen is not shaking and is legible, except there is a bright vertical band on the left hand side of the screen. And Q3 (US) BU406 gets hot (I'm not sure how hot it should get?)

I tried changing it (Q3), could only find a BU406G, not sure if materially different). But that had the effect that there was no beep, and the display kinda collapsed into a very thin squiggly line, and the BU406G got even hotter than the one it replaced.

So I've changed back to the original BU406, and it reverted to the previous behaviour.

Any ideas what else I can look at to try get it working properly?

Thanks!

 

[croissantking]

I have this on my SE/30, although it is very faint unlike yours. But it is in the same place. It appeared after a recap of the analog board and I too would like to know how to fix it.

 

[68kPlus]

What's that key hole looking thing on the front?

 

[croissantking]

I’ve solved my issue. It was a bad connection between the flyback lead and CRT. I cleaned up the little hole with IPA and slightly spread out the clips on the flyback lead.

Vertical band gone.