G07 Hsize too small

[ColoFan]

My cocktail ms pac man h-size seems to be shrinking…. The horizontal coil fails to increase it.
It's an electrohome G07. I checked a B+ at 120VDC. I recapped it. No change.
I cranked up brightness to show on the picture how far it is from the top and bottom edge.
I saw in another thread the wonderfully awesome and incredibly missed Ken Layton suggests changing the value of capacitor C515.
That default width capacitor C515 is at .53uF. Should I try to replace it with a lower value? Like .47uF ? Lower?
Or would anyone have any other advice?
Cheers!

 

[journeymandt]

@tron guy

 

[tron guy]

Was it previously fine?

 

[ColoFan]

I swear it's been slowly getting worse over the years. But I can't recall a specific event or day when it got significantly worse.

 

[tron guy]

Odd for sure. It's gonna be hard to get real advice. I'd have to have it in front of me.

 

[ColoFan]

Just FYI. I tried and replaced c515 from the original old .53uF to a new .47uF.
After the painful process, I can't say that I see any difference… I didn't mind trying, just in case, but I don't think I want to repeat this process iteratively with smaller values…

 

[tron guy]

If you want to ship it to me, I can look at it. Or you can just trade it in towards the one I have for sale right now. (Or we can continue to try to help you repair it, obviously). But it's a tough one. Has the flyback been changed?

 

[ColoFan]

First: thanks very much for the offer, so kind of you, we are fortunate to have your invaluable expertise, time, and willingness to help.
Second: No, the flyback was not changed in the last 10 years I've owned this.
But, I do see the width coil plastic casing is cracked and sort of loose to the touch, so maybe the inner core no longer reaches where it should and that might account for my width shrinking. Might it be worth replacing? (on the one hand it seems like an obvious yes; on the other hand, honestly, I've never seen much difference after replacing these...)

 

[tron guy]

The width coil doesn't do a lot. But, It never hurts to have a good coil.

I just wonder if the flyback is putting out different/inconsistent voltages, resulting in a screen size change. Nothing more than a guess at this point. Unless you have a hv probe, you can check it?

 

[behrmr]

Has this monitor been capped in the last 10 years? It looks like it needs it since there seems to be a geometry issue on the right side unless that's camera angle. I'd cap it and if the problem persists change the flyback.

 

[ColoFan]

I started with a new cap kit it last month, fully believing/hoping that would fix it... No luck. I am borrowing a high voltage probe and will test the flyback voltage and stability next.

 

[tron guy]

In the meantime can you shoot us top and bottom pics of the chassis?

 

[ColoFan]

A hp probe shows 20kV under the anode cap, same as another G07 anode of a chassis that is working well.
Here are pics in the game. (There is an unusual couple of fuses on the side rather than on the board.)
The width coil looks like it has an odd loop and has some goop on it, and certainly looks tampered with. That may be the next thing to try and replace.
I'll take pics of the other side when I remove it again…

 

[tron guy]

It looks like the original fuses were removed in favor of fuse holders. That is all. For the record , I have NEVER, EVER.......seen the correct value fuses when someone uses fuse holders.

Zero for 400.

The flyback wire needs to be re-routed.

Normal flyback range is 24-26kv (IIRC), so yours seems low to me. Though I'm not sure how that would impact your image.