area 51 sync problem with wg 25 k7000

[mitch]

hey everybody

my apologies in advance if the answer i'm looking for is elsewhere in the forums. But my computer, my net connection and this site's search engine are all being very difficult with me for some reason.

i just got an area 51 kit off e(vil)-bay. i threw it in my generic dynamo cab and (i think) the sync is all over the place (slanted picture, black lines, everything jumping and scrolling in all directions). for the most part theres no way to tell what is on screen. the picture is absolutely fine when my neo-geo or cps2 systems are in the cab, but it seems to hate area 51 with a passion.  the area 51 manual says for video display it needs "color RGB monitor, seperate positive horizontal and vertical sync OR negative composite sync, horizontal freq:15.750khz, vertical freq:60hz, video input1v to 3v peak to peak positive polarity".  the composite sync from the jamma harness (pin P) already goes to the   - horizontal sync   on the chassis (wg 25 k7193, P538 chassis board, P448 neck board). i know its probably something really simple like turning a nob, and i have a wg k7000 service manual but most of this stuff is over my head. any thoughts?

[SirPeale]

I know its probably something really simple like turning a nob, and i have a wg k7000 service manual but most of this stuff is over my head. any thoughts?

Well, have you actually *tried* turning the knobs?  Specifically the Horiz or Vert sync knobs?

[Ken Layton]

Area 51 can be kinda finicky on it's sync signal. First, do you know for a fact that the board is good? Second, did any socketed IC chips work loose during shipment? Is the hard drive and it's connecting cable good?

[mitch]

i've got the machine on now, everything seems to be working ok, there's sound, and video. when the screen can sit still for a second i can make out characters and text, the hard drive seems ok, no error indications from the on board led's, but i'll power down and check that all the ic's and cables are secure. i bought the board off e-bay in "working" condition, although there were no screen shots of the board in action so.........

[Kevin Mullins]

the area 51 manual says for video display it needs "color RGB monitor, seperate positive horizontal and vertical sync OR negative composite sync, horizontal freq:15.750khz, vertical freq:60hz, video input1v to 3v peak to peak positive polarity".  the composite sync from the jamma harness (pin P) already goes to the   - horizontal sync    on the chassis

Does he need to jumper from the -horizontal over to the -vertical sync pin on the chassis to complete the "composite" sync setup? 

I can't recall without pulling my only K7000 cab open.

[mitch]

yeah its still all over the place, what about kevins suggestion? can i get a wider range of adjustment putting jumpers on the pins and using the pots? jump 1 - 2 and 3 - 4 with alligator clips?

[Kevin Mullins]

Just did some poking around and I believe I was wrong on the jumper theory...... but check that your sync wire going to the monitor is for certain on the very last pin.
And I have my ground right next to the blue signal wire.
(but there are two grounds to choose from)

And you say adjusting the horizontal sync pot didn't do anything for it?

[mitch]

yup, the composite sync is for sure on the last pin. p1= r, g, bl, - , - , -  and p2= gnd, - , comp sync ( - = not used for those who dont know) and sync is the same as hold right? i used the horizontal hold pot and got alot closer than i was. i can now see whats happening on screen (mostly), but its still utterly unplayable (besides the fact i dont have any guns yet). the horizontal pot gets me from bad to worse, so right now i'm sitting at bad. the vertical still jumps a bit too, but is the lesser of the 2 evils.

[mitch]

i just found in the area 51 manual, mention of .40" and .50" i.d. ferrite bead ZIZN clamps that are to be installed on the jamma harness and gun harnesses to comply with FCC. i have no idea what those are and i'm pretty sure they didn't come with the kit. could their absence have anything to do with the picture being screwy? or does the board require additional grounding besides what goes through the jamma harness?

[use2bkewl]

I just replaced the monitor in area 51 and now I am getting a flashing screen whenever the gun is fired or reloaded. I havent tried messing with the color controls in the back yet should I? Anyone haver this prob?

[grantspain]

are the guns actually firing,usually a screen flash is when the gun fires but its not detected by the board-as you have changed the monitor you may need to recalabrate the guns and always make sure your screen is adjusted to detect the opto's,it has to be quite bright and the contrast at a good level

[Karetaker]

The screen is suposed to flash.... you're OK.