G07 vertical linearity fix

[mecha]

I wanted to share something I discovered last week. I'd made a couple inquiries to tron guy about what could be at fault, I don't remember what he suggested, but they wound up not being it. LOL

so I had a G07 from a Defender that I capped/overhauled way back in January that started out with the top of the picture squished. after I was done I tested it in a Rally-X at my old job, looked fine. bring it back to the customer's house... still mostly fine. about a week later I get a text saying it reverted back to the way it was. after the plague, multiple adventures, and a whole lot of nothing I finally got around to fixing it.

it wound up being the vertical transistors at X401/402 that I replaced that fixed it. I'll have to do some scraping for old pictures, but I took a couple of the rotting caps. (a G07 staple, apparently.. or necrosis of the caps as Randy Fromm calls it)

in fact the monitor looked even worse than the pictures. so... I assumed the solution right! assumption being the mother of all @#%$ ups my arse. (I stole them off a donor chassis)

 

[tron guy]

Nice work! In my defense, I don't suggest things from Randys flowchart that I assume have already been tested.

 

[mecha]

it was something complicated. not really obscure, just something I'd never come across to this point. when I saw the whole top half of the screen was collapsed I figured it was a bad transistor.

here's some pictures of before I worked on it and when I tested it after surgery.

 

[mecha]

some cap necrosis. observe the rotten C411, I'm sure that may have contributed to this fiasco. I didn't take a picture of the top of it, the outer layer was peeled way down.

 

[mecha]

my true before and after. I like to wash these.