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Main => Monitor/Video Forum => Topic started by: dan-g on August 01, 2011, 07:41:03 am

Title: rolling screen problem
Post by: dan-g on August 01, 2011, 07:41:03 am
hi

This is my first post,so i hope ive put it in the right place

basicly i bought a old arcade cabinet a few days ago,was bought as repairs needed.The monitor rolls upwards constantly,The cabinet has a neo geo mvs ,and on the cabinet it says Supreme video on the cabinet header.I was told to try turning the vertical hold on the back of the monitor to see if that does anything but it doesnt speed up or slow down the rolling.I am a total noob when it comes to arcade cabinets,so this is the first one i have owned.I have some pictures if anyone can give me some ideas what to look at.The machine powers on fine but soon as the neo geo screen comes on it just rolls upwards,The cart in the machine is puzzle de pon,i think its a jap cart so not sure if that makes any diffrence

(http://img.photobucket.com/albums/v146/wuweardan/9886f3d3.jpg)

(http://img.photobucket.com/albums/v146/wuweardan/5e0314af.jpg)

I removed this from back of the monitor to check connection and put it back on
(http://img.photobucket.com/albums/v146/wuweardan/c6da9369.jpg)

(http://img.photobucket.com/albums/v146/wuweardan/75e72ce5.jpg)

(http://img.photobucket.com/albums/v146/wuweardan/483770b1.jpg)

(http://img.photobucket.com/albums/v146/wuweardan/35546816.jpg)
Title: Re: rolling screen problem
Post by: grantspain on August 01, 2011, 01:39:28 pm
i think i remember those kortek chassis throwing up verical hold issues with snk games
first you can see a switch behind the colour adjusts,try that in the other position
next try joining the vertical and horizontal sync wires on the video input plug
Title: Re: rolling screen problem
Post by: dan-g on August 01, 2011, 05:05:36 pm
could you point me in the right direction for the vertical and horizontal sync wires on the video input plug? which ones are those
Title: Re: rolling screen problem
Post by: grantspain on August 01, 2011, 05:25:57 pm
Quote from: dan-g on August 01, 2011, 05:05:36 pm
could you point me in the right direction for the vertical and horizontal sync wires on the video input plug? which ones are those
yellow and white wires on the green 6 pin connector-just bridge them with a bit of solder

many years ago when this monitor first came out we had problems just like this-1000 mile rally was one of the boards that would not sync along with neo geo-on some of the chassis we had to bridge a 5k resistor from vertical sync to video ground to lock the picture but i think that was on a few namco boards
Title: Re: rolling screen problem
Post by: dan-g on August 01, 2011, 06:40:01 pm
see the lad i bought it from said it was working perfect ,then suddenly two weeks ago it started rolling,he said sometimes he could switch it on and it was fine but most of the time its rolling,and ive switched it on about 4 times and its rolling.

i did notice this damage on a wire

(http://img.photobucket.com/albums/v146/wuweardan/254c07eb.jpg)
Title: Re: rolling screen problem
Post by: grantspain on August 02, 2011, 01:01:58 pm
that is one of the sync wires,repair that in any case
for a chassis to just start rolling after working fine would point towards either leaky electrolitic capacitors or dry solder joints