Wells Gardner K7000 Questions/Concerns

[CanadianRyGuy]

Hello,

I'm really new to monitors but I've done some reading, so bear with me if I ask noob questions or anything like that.

I have a cabinet that was originally a TMNT, but was converted many times and when I got it it was a Buck Hunter. My monitor is as follows:

For any reason does this not look like it would be the original monitor/tube? One reason I ask is on the front the bezel does not match up with the edge of the screen on the top and thought it was odd but could have been just the way it was, see pic for what I mean:


 My first question is whether or not the operator would have needed to make any adjustments/modifications to the monitor to get it to work as a gun game? One reason I ask is there seem to be some odd looking wires that were soldered on the back that don't look to be the way it was intended, one is yellow going up to a capacitor and the other is red near the bottom right. Also the V-Hold right wire is not connected (is that the yellow wire?)






A few of the issues I've been noticing are that I can't quite seem to get the colours right, I'm going to continue tweaking but so far I've gotten it close but it still doens't look as vibrant maybe as it should.
When I power it on, I notice a quite loud electircal buzzing coming from the monitor that is kinda concerning but it goes away after a minute or so of being on.
There seems to be a spot of discoloration just to the right a bit of the top left corner. I think this needs to be fixed using a degausing coil?
Lastly, there seems to be some artifacting or whatever its called, but not sure if that is a symptom of the mointor or the board game (see pic of Vendetta)


As always, any and all help is greatly appreciated!

[baritonomarchetto]

The v-hold is not connected because the video signal has composite output, so H and V are sent on the same line.
The discoloration is probably due to magnetization: it will go away by itself if your degaussing circuit is working. The issue on the last pic is definitely NOT a monitor issue.
The buzzing likely comes from the flyback: it's "normal" up to some extent in these old and stressed monitors.

[CanadianRyGuy]

Thanks for the response!

How would I know if the degausing circuit is working? If it's not, is there something else I can do?

[baritonomarchetto]

You should run the monitor, then shut it down, leave it off for 20 minutes, run it again and so on.
If it doesn't work check if the degaussing coil is connected to the main monitor pcb; then check the degaussing circuit components, in particular replace the PTC thermo-resistor

[lilshawn]

those artifacts are from your game board. they have nothing to do with the monitor. make sure your roms are firmly inserted.

the k7000 is a great monitor. they made millions of them so parts are pretty readily available. that said, it's damn close to 30 years old since they've made them  and those capacitors on it are going to need to be replaced. "capkits" consisting of all the capacitors for this monitor are available for sale all over. I'm not saying a capkit is a fixall for every problem, but it certainly isn't helping things when the filter caps are acting more like a load then they are helping.


also check the flyback for cracks around the control pots on the side. if it's cracking, it can arc out and kill all sorts of stuff. including you. flybacks are still available for these chassis as well.


all the stupid jumper wires all over and random resistors and capacitors sprinkled here and there are mods done over the years to fix various issues or improve reliability. they are perfectly safe and should be there.

your discoloring in the corner may be the result of the metal bracket being magnetized. if powering it up a bunch of times doesn't automatically fix the picture, you may have to take a magnet in your hand and kind of gently degauss it in that one spot. get a bar type magnet (north on one end and south on the other) hold the magnet in your hand and point on end to the offending area and slowly and circularly get closer then pull it away off the corner of the tube. if the discoloration is worse, flip the bar around and use the other pole. it can take a few tries to get it decent...the auto degauss should take care of the rest.