Wells Gardner D9200 - vertical hold collapse

[mathewbeall]

Hi Folks - I have a cabinet I built about 18 years ago - and the WG D9200 is starting to suffer vertical hold collapse, as in - it's in the process - its about half the screen right now.

This is a flyback transformer issue right?

Matt

 

[gunblade]

is this a partial collapse or full picture but vertical size reduced?

 

[mathewbeall]

its about half way through its collapse...so partial right now - but should be full soon. I did some more reading - it looks like this is more likely the transistor on the large heatsink.

 

[Metal Slug]

Interesting. I've got one of these, it's working currently, but will be interested to read the results of your research in case you find out more!

 

[gunblade]

i would suggest checking/replacing all the electrolytic caps around ic301 and change ic301 itself- check the schematic for locations of caps
c847 in power supply section

 

[mathewbeall]

Ok - I got this guy out of the cabinet, and need to figure this out. Here is some video, and some pictures. It sounds like potentially a transistor?

 

[gunblade]

i can't tell if that is a vertical collapse or vertical sync issue
if you disconnect the video input so the no signal message appears does it do the same?

 

[mathewbeall]

Great question - let me fire it up and see tonight.

 

[mathewbeall]

So - weird.... with nothing plugged in , it never goes to the "no signal" screen. not sure why.

I definately started with vertical hold collapse although now clearly there is a sync issue as well. I am going to pull the chassis this weekend and take a close look at the cap's to see if any of them are bulging, and go from there.

 

[gunblade]

you probably need to up the screen volts on the flyback but you should get a no signal message and if you do not then that could be part of the fault