IGT Rolling black lines....

[dgaylor72]

I just picked up an IGT Triple Play Poker machine, I have no real info on it (and am unsure where to find it as I'm new to this).  But here's the problem, I have rolling horizontal lines across the screen.  They seen to be worse when playing as opposed to idle.  I read somewhere to turn down the high voltage on the flyback but I'm unsure how to do this.  Can anyone help me here?

Thanks,
Dave

[cowboygames]

There's a thick red wire going from the top of your monitor to a black or white transformer, or HVT,  on the circuit board. On this transformer there will be to knobs you can rotate clockwise or counter-clockwise. One control horiz output and the other controls brightness. Locate these and play with both while watching the screen to see which is which

[monitorman]

Does it roll from top to bottom and does it have a curve in the black line?

[dgaylor72]

No, they run horizontally and roll from top to bottom and back.  The picture holds steady but they slightly distort the image. What i'd descibe as ghost lines. 

[monitorman]

can you post a picture of the screen?

[dgaylor72]

I've also noticed some distortion from the speaker that coincides with the rolling lines.  I've heard people mention a possible ground loop problem but I have no idea how to check or repair that. 

[dgaylor72]

Yes, once I get home. 

[dgaylor72]

I can't seem to get the lines to show up so I can't post a picture.  Lemme see if I can describe it better.  There are multiple faint lines running horizontally at a slight angle from top to bottom on the screen.  I hear hissing and beeping from the speaker at the same time.

[dgaylor72]

Sorry monitorman, I misread your question.  Yes they roll from top to bottom and sometimes frokm upper right to lower left but no curve to the lines.

[monitorman]

The faint white lines sounds like the screen control it turned to high on the flyback transformer. The noise can be high voltage leaking from the high voltage lead on the picture tube and might clear up when you turn down the screen control.

[dgaylor72]

I tried the adjustments on the flyback transformer but to no avail.  I should also mention that I was able to swap the monitor with another but the lines were still there. 

[monitorman]

Then your next step would be to replace the power supply in the bottom of the game.

[dgaylor72]

Thank you, I'll try that.

[Tilt]

Got any pictures of the lines?  From parts of your description it almost sounds like normal EMI seen on alot of older GK MPU (3802 and earlier) boards.