1492 Ceronix problem with pincushioning of screen

[Amechanic]

i have been repairing a few 1492 Ceronix chassis from IGT machines. I have one that I can't seem to get the screens left and right edge straight. They have a round curve, but I'm. It sure if that's call pincushioning? I know pincushioning is usually an hour glass shape. I've changed the Horizontal Width control #185, IC LA7851 #218, plus a number of caps but no help. I was wondering if the automatic Bias IC could be bad #123.. I can adjust the screen wide enough to adjust the round corners out on my Fortune 1 machine, but that machine has smaller card. I do not an a PE or a PE+ to try it on. I know that they have a larger card size, so I'm not sure if this Ceronix would work on them. I was considering changing the Auto Bias IC #123, but I don't think that's my problem..

[rokgpsman]

Have you tried changing any of the caps around the feedback transformer or horiz deflection?

One of the guys at work used to ask, "why is it always the last part I change that fixes the problem", and we'd tell him "because when that fixes it you stop replacing parts".

[Amechanic]

Yes all bad and marginal cap were changed first thing. It's almost impossible to check voltages when you don't have a Tester. My Tester is a old CRT and metal mounting chassis that I run off an extention cable to check my work outside of the cabinet.

[Firebird]

Try changing out 185, it is a transistor part#2SC4159E. This solution was on a repair log I used when we had the 1492 monitors still on our floor. I am attaching a copy of the repair log, it may be useful in future repairs.

[Amechanic]

Thanks.  I forgot to mention that I did replace that part after I brought the 1492 chassis back to life, and I noticed the issue .. I see my problem is referred to as barrel distortion not pincushioning.

[Badbaud]

There is a small coil with a magnet on top. Remove it and put it back in the other way.... reverse the leads on the PCB.