CRT TV left->right brightness issue [Solved]

[gauze]

I have a mid80s Hitachi TV that still works but has an issue, what I am seeing is when there is an object that is bright white on the screen, to the right of the object there is bleed over of the brightness that continues to the right edge of the screen (getting less bright as it moves), and after HBLANK it still continues to the next scan line as well (but less bright).

I've already replaced all the caps in the part of the PCB marked "VIDEO/CHROMA", I don't think it's a deflection issue so I haven't touched that, I'm not sure how to judge what is going on, it seems like all the guns stay on when they should be off, what could cause this?

thanks

 

[Nigel Goodwin]

Check the 200V supply on the CRT base with a scope, the decoupling capacitor for this rail (probably on the main board) is possibly O/C or high ESR - it used to be a fairly common fault on various sets.

 

[ronsimpson]

Do you have a scope. There are a number of places where this problem could be from.

 

[gauze]

I don't have a working scope (my Tektronix 561a has an issue too even after being retubed) I can check ESR though on PS caps, but not today.

Thanks.

 

[gauze]

Check the 200V supply on the CRT base with a scope, the decoupling capacitor for this rail (probably on the main board) is possibly O/C or high ESR - it used to be a fairly common fault on various sets.

BINGO! I looked around and the only cap rated over 200V in the area around the flyback was 4.7uf, pulled it and it had some electrolytic crud around one of the leads, replaced it, streaks gone!

Thanks.

 

[Nigel Goodwin]

BINGO! I looked around and the only cap rated over 200V in the area around the flyback was 4.7uf, pulled it and it had some electrolytic crud around one of the leads, replaced it, streaks gone!

Thanks.

Like I said, it was a very common fault back in the CRT days