arcade monitor half screen out of sync! PLS HELP

[juanchocnva]

WATS UP FORUM!'

i recently (2 months ago) bought a neo geo cab   

everything works ok the thing is rocking am luving it

is just that the monitor is giving me a headache 

half of the screen from the center down the R G B lines are out of sync dont align
a white line on the top as is going down it starts looking like the Atari logo

Ive tried the options on the back, the turning things for color brightness and focus from the back problem is that the top of the screen is fine 

if i keep moving the controls on the back my top of the screen picture starts going out of sync too and the bottom worst
something is wrong !!!

am just out of luck??   

please i need to fix this is very bothersome the arcade monitor is a zenith 6a63ad625x - 04rc0105-005

if you have an idea of what is causing the problem
please 
share it i beg you

thanks for reading this post
 

[grantspain]

do you mean you have a vertical linearity issue?

post a photo of the a screen shot and find out the model/make of the monitor

[juanchocnva]

zenith 6a63ad625x - 04rc0105-005

am surprised by how good the picture looks here
prob my phone did the trick but is very out of sync you can only tell by looking at the insert coin things at both sides of the bottom screen

[juanchocnva]

hope this helps

also i noticed there are 3 "levers" that ive been moving in order to fix this problem they are on top of the monitor tube i dont know what each one of them do or how to used them i tried finding a manual
but this monitor is just old Zenith makes bad tvs dont know much about their monitors but ill say they suck...

if i can only know what each lever corrects ill be able to make my picture better so if you know a place to look of video !!!

[lilshawn]

if it looked good, and now all of a sudden the colors don't line up, i'd say the yoke has been knocked out of alignment or been broken. Some monitors are notorious for the plastic making up the deflection yoke getting brittle and cracking and falling away from the tube slightly causing the colors to get all fired off in different directions in some parts of the screen.

turn off the monitor and see if the coil on the tube can be moved very easily. If it's loose or has broken away, this is the cause. if it's tight still you have something else going on. (some monitors have magnets that they use to fix these kinds of issues, maybe one has fallen off)

[juanchocnva]

thanks  lilshawn
its seams that deflection yoke its a little loose on the bottom and since am having problems with the bottom of the screen seams like that might b the problem
i want to try and see


in case that is the issue how to tighten it or fix it??
 

[lilshawn]

if you can prop it back into place (say with Popsicle sticks or whathave you) and the picture returns to normal in those areas, then you will need to use some silicone to hold it in place. if not, you probably have some wedges or magnets that have fallen off. is there anything laying in the bottom of the cab?

[juanchocnva]

thanks again lilshawn i tri3d
pushing the yoke and putting silicone but that didn't help the picture 
there is nothing in the pbc of the monitor ,,, so even i it fell the previous owner dispose of it dunno
i think the problem is inside the tube maybe?

is just that the red green and blu colors dont aling on the bottom of the screen while on top everything is good!
\

something else i should try ?? 

[lilshawn]

have you ever seen it working 100%? your going to have to search the bottom of the cabinet. There is probably a magnet strip or something that has fallen off.

[MonMotha]

Are there any rubber stoppers between the yoke and the tube (right up where the neckstarts to flare out to the back "bell" of the tube)?  Normally, there would be at least 4, possibly more to seat the yoke right and adjust the edge convergence.  They're normally glued in place that procedure is done but some cheap monitors didn't bother, so they fall out during transport.

Also, for grins, make sure your convergence rings are where they should be.   They should be snug up against the back of the deflection coils, and they usually draw a line down them at the factory so you can see if they're set properly (or at least the same way THEY set them).  This mostly affects center convergence, not edge, but it's worth checking.

[lilshawn]

if you want to take a stab at setting up the convergence, there is a very good how to in the service manual for the k7000.

http://www.wellsgardner.com/pdf/Service/K7000.pdf

it starts about page 5.

[juanchocnva]

ive never seen this monitor working 100%
since i got it i noticed the monitor had aliment issues on the bottom.....
and after moving  the convergence levers on the back the thing got worse.... i tried moving them but i cant tell what each of them do....
and the line for the convergence things was glued with silicone but is not longer there so dunno the way they were align before ....

also trying to find for the rubber things, there is nothing on the cab....... checked everything (and cleaned it) if it fell the previous owner did something to it

and yea the yoke has rubbers stoppers 3 of them on on top one left one right and..............none in the bottom that why i thought that might be the problem but after pressing the yoke towards
the monitor i saw no difference in alignment or anything......



thanks guys  lilshawn and monmotha ......



  i need to fix it ... cause is not much of a big deal but after playing for 20 min you start getting dizzy 

[juanchocnva]

should i be concern for this ??

is just hard to clean with a q tip
not so sure is the board is making any connection

\
also lilshawn with the manual u shared
i noticed that the sync cable coming from my neo geo board is conected to the monitor's ground and -Horizontal sync
there is no vertical

shouldnt this cable be connected to +V and +H sync  ??
my board is very similar to the one on the manual  and the harness says is a wells gardner
maybe the previous owner simply change the screen ?? possibly>??

[MonMotha]

That neck board looks fine to me.  The solder blob is clean enough that it's almost surely intentional or maybe a repair from a broken trace.  The giant resistor looks factory.  The gunk is just flux residue.  Given how long it's probably been there, I wouldn't bother trying to clean it, but isopropyl alcohol (99%+ - any water will cause problems) will take it right off.

As far as sync, arcade games usually use composite sync.  This has both horizontal and vertical syncing info on one wire.  You're describing what sounds like a convergence issue.  Nothing to do with deflection.

It would probably help if you can get a picture of the screen with a grid / crosshatch pattern.  Please use a "real" camera if you have one, not a cell phone.  The picture quality difference is surprising.

[lilshawn]

the k7000 series of monitor went through many changes over the years. You look like you have an early model. It's not uncommon to have a board with extra parts attached to the backsides of boards...or with parts missing entirely.

Sync is what the monitor uses to time the video signal there are 4 different types of sync:

horizontal negative
vertical negative
horizontal positive
vertical positive

a monitor needs at least ONE of these to properly synchronize the video to the scanning of the monitor. Some games however out put several or even mixed signals and separate them accordingly in the monitor using a sync separator. AKA Composite sync.

you have a properly sync'd picture.

(okay everybody i know this is wrong but i'm going to simplify this issue)

stay with me here...

now you have to realize what happens next now that the monitor is timed to start drawing a picture on the screen...

there is 3 streams of particles comming out of the end of the tube (one for each color red green and blue) the 3 beams of energy particles coming out of the end of the tube now has to travel to the front portion of the screen to draw a picture... except it only can travel in a straight line. so the beams travels to the front of the screen where they go splat and make a great big dot in the middle of the screen. how fun 

Because the beam comming from the end of the tube  is sensitive to magnetic fields we use 2 magnetic coils to pull the stream of particles from a straight line to a curved line. This is called the yoke. it has a horizontal coil and a vertical coil. these pull the stream of particles vertically and horizontally to position this dot wherever we want on the screen.

this yoke must be precisely aligned to get the 3 beams to properly hit the tiny dots on the screen...otherwise the beams get pulled off their course and hit a dot different from where it's supposed to. this is why you can see your insert coin text (that should be white) seperated into red green and blue. The beam is getting pulled off course.



Now, WHY THIS IS THIS HAPPENING?!?!

most likely:

the yoke isn't properly aligned with the tube
there are some additional magnets missing (sometimes they add magnets to the back of the tube to help align stuff up better)

Less likely:

the purity rings on the neck have become loose or have been knocked out of place.
a magnetic field nearby is causing the distortion.

Least likely:

electrical problem
Wiring issue
Electronic issue


absolutely not likely:

sync issue
Cat and/or dog
game issue
power problem
Solar Flares
dragons

[juanchocnva]

think this pictures are better

and lilshawn and monmotha i really appreciate the effort your putting into this problem am having
 



thanks


first pic: top of the monitor
second: bottom
and third: the hole thing is when i take the picture of the entire monitor
when the image looks ok from the distance

[juanchocnva]

i think this can help my case does anybody know where can i buy this magical sticks

 

[buffett]

you can find them for free on most old tv's.

look around on trash nite and pick up a couple broke sets.

take a razor knife and remove them.
clean your tube so the new glue/silicone will stick to it.

you may only need two strips you may need several there is know knowing how many it will take.

take your time and find the sweet spot when you insert the strips.

Peace
Buffett

[juanchocnva]

thanks for the response but dont have any crt laying around to take them out...
ill try paper if there's nothing special about this strips

[buffett]

they need to be more rigid than paper.

you will have to slide them around to get it rite.

i have heard of people using a plastic for sale sign cut into strips.

Peace
Buffett

[lilshawn]

i peeled some of those strips out of a monitor i was tossing. it just seemed like a small square of thin metal...not even a magnet. least i couldn't stick it to anything. could have been too thing to do much too.

[juanchocnva]

well thanks again guys ill either try to find an old tv or cut some metal strips
although am not sure if sticking a metal strip into an arcade monitor while is on is considered safe ....


i guess l'll find out