Ivan Stewart monitor spark/flame

[mrmcw]

Plugged in Ivan Stewart and heard some cracking/popping when the monitor started up. Unplugged the machine then opened the back. I couldn't see anything so I took a video.

It seems this connector is causing sparks and fire!! I took a screengrab of flame.

Any help with why this might be happening would be appreciated.

 

[Pitas_arcade]

Quick grab the marshmallows!

 

[security0001]

are you sure its not coming from those crappy Jamicon caps and going to the connector?? was the connector cracked on that side?

 

[mrmcw]

Seems like I will need to recap then? Anyone located in North NJ area?

 

[SuperSprint]

Plugged in Ivan Stewart and heard some cracking/popping when the monitor started up. Unplugged the machine then opened the back. I couldn't see anything so I took a video.

It seems this connector is causing sparks and fire!! I took a screengrab of flame.

Any help with why this might be happening would be appreciated.

What do these wires connect to? Make contact with?

 

[mrmcw]

Sorry as I am new to this. The cable (black,brown,red,orange) connects to the back of the monitor.

 

[mrmcw]

Here's some info as to what we are working with

 

[mrmcw]

All kinds of numbers

 

[SuperSprint]

Jen Shinn is your problem. Probably an "upgraded" Wells Gardner K7000 series. Find a K7000 chassis and replace it.

 

[SuperSprint]

Looks like a 25in tube? Assuming it was a K7000 (check yoke impedances) , here is a chassis from a reputable seller (Dave Countryman) that should work.

Pardon Our Interruption...

 

[SuperSprint]

Back to what probably happened... What I see looks like high voltage arc (blue), plus some yellow flames.

As you can see on the attached schematic (K7000, not yours), the neckboard has two sets of wires going to it. The upper left is RGB signal (TTL), the lower right is heater (6V), GND, contrast (12V), and gun drive voltage (+120V). None of those are sufficient to arc as seen.

If there was a break in the HV insulation and it allowed Hv into these circuits, it would then arc to the closest (i.e. lowest resistance) ground. In this specific location, that would be the ground pin in your 4 wire connector. If the break were closer to the tube, there are lot of places to arc over. But this location is closest to the flyback, which suggests internal breakdown in the fly.

You said, "Sorry as I am new to this"

That raises an important question: What is your level of experience with electronics and CRT monitors? The latter is important because the HV section of a CRT monitor is >20,000V, even when unplugged. Don't let that scare you away, but it is important that you know what you're dealing with and how to handle it before you start poking fingers and tools into a chassis. Start by searching for "how to discharge a CRT"

 

[mrmcw]

Totally new to all arcade / electronic repair.

I have heard and am a bit scared of the shock, but I have read about discharging.

Eventually I'm gonna have to get the balls to do it.

 

[mrmcw]

Back to what probably happened... What I see looks like high voltage arc (blue), plus some yellow flames.

As you can see on the attached schematic (K7000, not yours), the neckboard has two sets of wires going to it. The upper left is RGB signal (TTL), the lower right is heater (6V), GND, contrast (12V), and gun drive voltage (+120V). None of those are sufficient to arc as seen.

If there was a break in the HV insulation and it allowed Hv into these circuits, it would then arc to the closest (i.e. lowest resistance) ground. In this specific location, that would be the ground pin in your 4 wire connector. If the break were closer to the tube, there are lot of places to arc over. But this location is closest to the flyback, which suggests internal breakdown in the fly.

You said, "Sorry as I am new to this"

That raises an important question: What is your level of experience with electronics and CRT monitors? The latter is important because the HV section of a CRT monitor is >20,000V, even when unplugged. Don't let that scare you away, but it is important that you know what you're dealing with and how to handle it before you start poking fingers and tools into a chassis. Start by searching for "how to discharge a CRT"

Thanks for taking the time to explain all this. I could search the forums for hours and still be lost.

 

[SuperSprint]

Eventually I'm gonna have to get the balls to do it.

It's no big deal. Get a flathead screwdriver. First, kill power to the monitor. Then, connect a jumper wire from the screwdriver shaft to the dag wire (bare metal braid, around the tube, near the face). Slip the screwdriver under the cup and touch the anode. You will hear a pop. Some are easily audible like a twig being snapped, others are barely audible. Give it a second and touch it a second time for good measure. That's it!
I then unclip the jumper from the screwdriver and connect it to the ultor (the anode hole) to keep it from picking up a static charge.

You've already got a dead chassis. Grab your tools and lose your anode virginity.

As long as you're attentive to the HV section and when it's charged, you're way more likely to get bit by the back to neckboard when you are dialing one in (and trying to lean around and look at the same time).