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Main => Monitor/Video Forum => Topic started by: smartbomb2084 on February 12, 2007, 05:59:59 pm

Title: WG25K7191 doing the 'hula'
Post by: smartbomb2084 on February 12, 2007, 05:59:59 pm

Hello all,  I have a WG25k7191 in a DYNAMO cabinet that is doing the 'hula', that is, it is oscillating like hawaiian hips and doesn't appear to be a sync problem but more like bad power regulation.  This is one of those hated Wells-Gardner/Zenith hybrid jobs that after 17 years are nothing but trouble.  I have replaced all of the electrolytics including C55 with no change. It is not the game board or the game power supply.  Could this be caused by a faulty STR30130 Regulator?  The B+ is 130.4 Volts.

If you can help, THANKS in advance.

Title: Re: WG25K7191 doing the 'hula'
Post by: Kevin Mullins on February 12, 2007, 07:51:00 pm

Is C55 the larger filter cap in the power supply section?
(I just don't feel like digging up the manual)

Title: Re: WG25K7191 doing the 'hula'
Post by: JoeB on February 13, 2007, 03:17:57 pm

When you say oscillating, do you mean the picture is moving up and down a little? Mine was having the "shakes". It will shake 1/2 a mm up and 1/2 a mm down non stop (after 3 times per second!)

I was running ArcadeVGA -> JPAC -> monitor.  I've fixed it (so I hope) by taking the sync wire and running it both to Horizontal Sync and Vertical sync (which is the way it was originally wired up with a real arcade PCB).

Title: Re: WG25K7191 doing the 'hula'
Post by: smartbomb2084 on February 13, 2007, 04:57:42 pm

Yes Kevin, C55 is the large filter cap in the Power Supply.

No Joe,  the picture is steady Sync - wise,  both vertically and horizontally.  The oscillation is more like undulation.  That is, side to side with a wave like motion up and down,  not jittery which is an entirely different symptom.

I'm really leaning toward some type of power regulation problem.

Title: Re: WG25K7191 doing the 'hula'
Post by: SirPeale on February 13, 2007, 07:23:20 pm

Quote from: smartbomb2084 on February 13, 2007, 04:57:42 pm

Yes Kevin, C55 is the large filter cap in the Power Supply.

I thought it was C57?

Title: Re: WG25K7191 doing the 'hula'
Post by: smartbomb2084 on February 13, 2007, 07:55:31 pm

Sorry Peale, my man, it is C55- 560MF 200V.  Check the drawing.

Title: Re: WG25K7191 doing the 'hula'
Post by: SirPeale on February 13, 2007, 08:00:42 pm

Quote from: smartbomb2084 on February 13, 2007, 07:55:31 pm

Sorry Peale, my man, it is C55- 560MF 200V.  Check the drawing.

Oh, the big mamma-jamma.  I thought you were talking about C57, the 47uf, 160V cap.