My mk1's transformer is a fuse destroyer need help!!!

theforce19

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My mk1's transformer is a fuse destroyer need help!!!

Hi, everbody

So yesterday I turn on my mk1, it turns on, screens messed up ok sure. So I shut it off, I go and grab my camera to take pics of the messed up screen. So I when I turn it back on, I hear a loud vibrating sound coming from the transformer and the monitor shuts off. I check my transformer and the right fuse is blown. Ok so today I go out and buy some new fuses and replace them. So when I turn it on today it turns on again the screen is messed up. So I shut it off and go and eat dinner. When I come back to turn it on again I hear that noise coming from the transformer, the monitor shuts off again and I have another blown fuse!!!
I don't want to keep buying these fuses. Every second time I turn it on, it shuts off and a fuse is blown.. Why??? Help!!!! I know I use the right fuses all 3A, thats what is says to use. Could this be a grounding problem??? I feel like I want to get rid of it now!!!!! I don't see anything touching the transformer (wires or anything metal). Also its always the right fuse thats blown, the left fuse is always fine.
 

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More Pics*

1st pic shows the wiring underside. *I circled in red which fuse keeps in blowing*

2nd pic better pic of underside wiring

3rd pic shows an above view of the transformer. *I circled in red which fuse keeps in blowing*

4th pic shows the left side of the transformer. The fuse which I circled in green never blew out once.. only the right side..

5th pic shows the plug for the machine?? could this be the problem?

Thanks
 

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The transformer could have shorted internally. Do you have a ring tester?


If you don't care about blowing other fuses you could try to disconnect all ac loads (switcher, marquee light, monitor) and then turn on the machine. If the fuse doesn't blow plug in each component until it does blow, revealing the problem. If the fuse blows right away it is most likely a shorted transformer requiring replacement of the transformer.
 
It looks like the main AC input to the cabinet. It could be anything electrical. If there is a Molex for each device, you can disconnect them leaving the switcher and board only to be powered to verify it will play blind. You can then begin plugging in other things to determine your point of failure. Marquee, monitor, etc, etc. At least it would help finding out what the problem is. Does all the power in the cabinet run through the iso transformer?
 
The only thing being powered by the isolation transforrmer is the monitor and coin door lights. Since this is a mame setup sorry my dumb mind forgot to mention. Everything else is plugged into a power surge strip(marquee, pc,then the plug for the transformer.) So prettty much the transformer only powers one thing, the monitor. So would that mean I need a new transformer? Sadly I don't have a ring tester. But I still don't get how it doesn't blow the first time I turn it on, only the second time and why always the right fuse??

Thanks
 
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Ok For some strange reason the fuses don't want to go in. Is there a special technique? They fitted in yesterday and I see nothing blocking the inside of tubes.


Thanks
 
Ok an update so far. I found a crack in both of the tubes for the fuses. It's a long spilt right in the middle. So tommorow I will be heading back to The Source to pick up Fuse Holders. And once I get those installed I will update again.
 
The only thing being powered by the isolation transforrmer is the monitor and coin door lights.

Is this an original Midway MK cabinet ?
If so then the marquee light fixture is probably tied into the same output as the monitor.
(all the violet/purple colored wiring)
A shorted ballast for the fluorescent light could cause the same symptoms.

So once you get the fuse holders situated, unplug the monitor, marquee light, etc .... turn machine back on and see if it blows.....then plug each back in one at a time as mentioned before until the fuse blows again to narrow it down.
 
Is this an original Midway MK cabinet ?
If so then the marquee light fixture is probably tied into the same output as the monitor.
(all the violet/purple colored wiring)
A shorted ballast for the fluorescent light could cause the same symptoms.

So once you get the fuse holders situated, unplug the monitor, marquee light, etc .... turn machine back on and see if it blows.....then plug each back in one at a time as mentioned before until the fuse blows again to narrow it down.

Hi, Kevin it is an original mk1 but the marquee light has been replaced with a plug in one. So it just plugs into the wall and their is an on off switch.

Update again

I replaced the fuse holders with brand new ones and threw in new fuses. I unplugged the monitor cable and let the transformer run by itself. I turn it on and heard the transformer turn on and no blown fuses! I turn it on and off 5 times and let it run for at least 5 mins between each turn off. So I check the fuses again just to make sure. They still look brand new. So it only fuses when connected to the monitor. Any ideas what is causing this on the monitor???

Thanks
 
There could be a multitude of problems with the monitor. Most likely a blown flyback or HOT, but it could be shorted diodes or other components. What kind of monitor is installed?
 
It's a WG K7000(well 7197 but there the same).I was thinking it was the flyback but I have to remove the monitor from the cabinet. Also do I have to discharge it?, if I'm checking the flyback. I'm thinking yes(dumb question) but I don't feel safe discharging it myself.
 
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It's a WG K7000(well 7197 but there the same).I was thinking it was the flyback but I have to remove the monitor from the cabinet. Also do I have to discharge it?, if I'm checking the flyback. I'm thinking yes(dumb question) but I don't feel safe discharging it myself.

did the monitor ever work in this? I had a K7000 flyback crap out once, and it did significant amounts of damage to the chassis, and no fuses went on it, it just kept running like this. it wasn't in a Midway cab either though, so who knows. lol

every time I tried discharging that monitor, it never made the little arc. I'd say you're safe enough with just leaving it off for a day or so and taking the monitor out without discharging it if you're just trying to avoid that step.

eventually you should go about wiring the marquee fixture in properly.

as for the monitor, I'd encourage trying to find someone local that can give you a hand with it, cause there's obviously something wrong with it.

just out of dumb curiosity, are the adjustment knobs on the flyback white? lol
 
Yeah, I agree with what Mecha said. There is no need to discharge the monitor if it has been off for more than a day. You also shouldn't have to pull the entire monitor out, just remove the chassis (circuit board), neck board, and disconnect all associated wiring. One wire, a black one coming from the back of the tube to the neckboard, may need to be cut. All of the others will either be disconnected or stay with the chassis.
 
I have no idea if the monitor ever worked, he pulled the Mk1 out of a warehouse. I got it for $175. I don't think the adjustment knobs are white, they are covered in thick dust but they look black but I will make sure. Local?? I don't think there are any locals from my area on Klov. Also the Arcade shops don't care they would just tell me to replace the entire monitor but I will check still. As much as I trust you guys, I don't trust myself so I got a guy coming in to discharge it just in case, I will also tell him to check out the chassis. He also owns an arcade shop.

Thanks
 
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Plug the monitor back in and see if it still blows the fuse. If you had fast-blo fuses in before and have slo-blo fuses in now, it might not blow now.

Also, check that the black wire is connected from the tube to the neckboard. if not, it'll cause some current arcing between the chassis and frame that can blow the fuse (and cause monitor problems)...
 
Im 100% sure that I always had slo-blo fuses. But today I went out and bought some more slo-blo fuses(3a yes it's the right ampage) and new fuse holders. I installed the new fuse holders and put in the fuses. The monitor didn't even turn on and I heard that sound again. So the right fuse blew again. The left fuse was still good. So I threw in another one in the right. I unconnected the monitor cable and ran the transformer for at least 5 mins. I turn it on and off for 5 mins. None of the fuses were blown, I still don't get it. Even the coin door lights lighted up(connected to transformer).
I will check the black wire.

Thanks
 
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