Image is shifted down about an inch

processedmeat

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Hi all, so I have a K7915 monitor and the image didn't fill the screen about 1.5 inches from both the top and bottom when I got it.

I've played with the horizontal pos knob, done a cap kit, replaced the horizontal width coil, and got Bob Robert's horizontal width kit and put the smallest cap (.1uf) in C58 and now I'm just an inch from the top away getting just right.

Is there anything else I can try? Would putting two smallest caps in series from the kit in C58 cause any damage to the monitor? Does the horizontal raster position do anything? Its currently plugged into the left pin. Would replacing the HOT make a difference? I get 123V B+ so it doesn't seem like a power thing.

Thanks for any help you can provide.
 
Is this a horizontal or vertical mount monitor?

When you say top to bottom are you referring to the short dimension (vertical) or the long dimension (horizontal or width).

If it is the short dimension try adjusting the vertical height pot.

Posting pictures always helps.

Ed
 
if you have done all this you must have been way off to start which would tell me there is something else wrong that should be fixed. did you do a tube swap on this?
 
Is this a horizontal or vertical mount monitor?

When you say top to bottom are you referring to the short dimension (vertical) or the long dimension (horizontal or width).

If it is the short dimension try adjusting the vertical height pot.

Posting pictures always helps.

Ed

Long dimension, vertically mounted, so I think I got it right worrying about the horizontal width stuff.

The first photo is the after and the second is the before the fixes.

Did you try a different adjustment board?

What game PCB are you using to test it?

I don't have any other boards or anything. My first cab.

APB

So is there anything else I can try? Would putting two smallest caps in series from the kit in C58 cause any damage to the monitor? Does the horizontal raster position do anything? Its currently plugged into the left pin. Would replacing the HOT make a difference? I get 123V B+ so it doesn't seem like a power thing.
 

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if you have done all this you must have been way off to start which would tell me there is something else wrong that should be fixed. did you do a tube swap on this?

I didn't do a tube swap. My first cab, so in my excitement over when I picked it up, I failed to see these flaws that are so apparent now :( At the very least, I'm been learning a lot more than if this cab was perfect.
 
Do not toy with capacitors, or you very likely will damage your monitor.
If it was mine (and i would really like it was so being APB a great game) after tweaking the horizontal position potentiometer with no luck I would check components (in primis resistors) in the horizontal deflection circuit.
 
Long dimension, vertically mounted, so I think I got it right worrying about the horizontal width stuff.

The first photo is the after and the second is the before the fixes.



I don't have any other boards or anything. My first cab.

APB

So is there anything else I can try? Would putting two smallest caps in series from the kit in C58 cause any damage to the monitor? Does the horizontal raster position do anything? Its currently plugged into the left pin. Would replacing the HOT make a difference? I get 123V B+ so it doesn't seem like a power thing.

So you are definitely correct about the orientation and that it's the horizontal width you need to adjust.

Based on the statement of "It's currently plugged into the left pin", I would try moving that to the center pin. There is a jumper that does that and if you center it, then you can work on the horizontal width adjustments and perhaps get this centered.
 
should be a h-pos jumper also tucked away on your monitor board. dont expect much though from the jumper change.
 
adjust your H-Hold and H-position pots.

they should bring the image in the screen.

Peace
Buffett

Please try this.

Move the H-Hold through it's whole range. At some point, the picture may snap to its correct location and hold well. This may happen after the hold gets worse, or "magically" happen in a spot that wasn't very good.
 
Please try this.

Move the H-Hold through it's whole range. At some point, the picture may snap to its correct location and hold well. This may happen after the hold gets worse, or "magically" happen in a spot that wasn't very good.

Unfortunately this didn't work for me. The image just bends under itself at the top. Thanks for the reply.
 
Does this linearity coil look like it okay? It seems like the wire isn't tightly coiled up all the way.
 

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This may be a useless observation, but isn't a 7915 a medium-resolution monitor? Would that have any bearing on this issue?
 
This may be a useless observation, but isn't a 7915 a medium-resolution monitor? Would that have any bearing on this issue?

yes it is.

but if it was a mismatch chassis to yoke or vice versa, it would not have a stable pic or have already damaged the chassis.

Peace
Buffett
 
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