Wells Gardner 25 inch K7000 picture doesn't fill screen

[ashmantrio]

Hello, I have a WG 25K7193 monitor with an RCA tube in my Neo Geo cabinet and for some reason the picture doesn't fill the screen horizontally or vertically.



The grey area is all the area of the screen that has no picture. 

The vertical size pot on the remote board has been adjusted, its set as tall as possible. I've adjusted the 50/60hz pot and that did make it slightly bigger, it was even smaller before, but it still doesn't fill the screen. I bought a cap kit from ebay and recapped the board which didn't do anything. And the person I bought it from said the flyback has been replaced recently.

So I don't know what else to try to get it to fill up the entire screen. Any help would be greatly appreciated!

[ashmantrio]

I replaced the tantalum capacitor at C51 on the board because I read that could cause problems, but there was no change in picture size. 

I guess the next thing to do is try changing IC2 or 3?

[grantspain]

whats the part number of the power regulator ic?

[ashmantrio]

whats the part number of the power regulator ic?

hmm in the service manual for the k7000 it says IC4 the regulator IC is STR3123 part number 086X0188-001

[ed12]

so if u measure the output of that ic
it must be 123 volt's dc
if it is under then the reg may be bad ?
this is a common old time problem with str's
and where i get 123 from is the actual part #
str did us a fav that way
ie str 120=120 volt out
str 135 = 135 volt out
and so on..

ed