k4900 series, blue spark from inside tube

darer234

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Ikari Warriors cab problems, blue spark from inside tube

I have a ikari warriors cab i am trying to get up and running.
When i turn the game on the neck starts glowing orange like normal,

But after about a minute a blue light (i assume electricity) starts forming on the blue plastic or rubber looking thing inside the tube. it gets brighter and brighter and then arcs and makes a pop noise, then the tube glows orange again until the blue light gets enough strength again and then sparks.

sorry for all the novice language. anyone got any ideas?

The screen turns on bright white, and during the pops its like a purple wave goes around the edges.

please help
 
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Possibly an internal short.
A crt rejuvenator/tester may or may not help.

Is everything properly connected such as the DAG wire that goes around the tube ?
 
Hi, DAG? what does that stand for?

There is a line of glue and it looks like it has a wire in it.
It is cracked right where the color rings meet the glass of the tube. THE TUBE IS NOT CRACKED, but the line of glue, if that makes any sense,
i could take pictures.

also i noticed that when i turn the BLK LEVEL pot it still comes up white screen just like before but there is no sparking or blue glow.

also when the blk level is turned up, the blue glow starts at a blue capacitor looking thing, but I cant really tell if it is actially a cap inside the tube or not.

Why would the blk level cause the sparking?

could something just be causing a short or could a bad switching power supply cause a problem like this?

Would too much voltage to the monitor cause the spark?
 
Ok i believe this is my dag wire.

DSC01480.jpg


it seems like it is touching a few components, is it supposed to?

Also it is definitly the wire that had the line of glue on it. also you can see what i mean about the crack in the glue.
DSC01481.jpg



ok both these pictures are with the blk level down so there is no spark or blue glow from the tube, just normal orange

here is the screen when on
DSC01488.jpg


and the neck glow

DSC01492.jpg


thanks for looking!
 
The DAG wire prevents build up of High voltage static.

Check these pics out and see if it clears anything up for ya.
 

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ok i see my DGA wire, it is hooked up and a wire comes from the dga wire to the back of the neckboard, it is soldered on. i tried shaking it around, no change.

What should I check next?

I have a new board and power supply comming soon from burt, hopefully that clears this up.

But idk, its pretty weird that it only glows blue when the blk level is turned up.

wth?
 
The tube has an internal short, and you will need to use a rejuvenator to try to clear the internal short. If you are unable to remove the internal short, your tube is trash.
 
Yeah, I was starting to confuse this with another thread. (dag, degauss,dogonit)
But still hoping it was some sort of voltage buildup causing it to go nuts like that.
 
Just had a 4800 (13" version of the 4900) that had a blue lightening storm inside the neck. Turned out that the tube was shot, same symptoms and picture on the tube.
 
ok so its a internal short in the tube.

when i first brought this home the picture did come up, only after i took the pcb out of the cab and then put it back in did it start doing this

could i have caused this short simply front moving the cab around(it has wheels, but i am on tile)

also there is and never since i brought it home sound or marqee lights
 
Ok will do, the fuse on the power board is soldered onto the board,

can i just test it like that or, do i have to discharge the monitor and actually yank the fuse before testing?

sorry for all the questions, but I figure its the only way to learn.


Update:

Ok i tested the fuse that is on the power board, the one that is soldered to the board and has a plastic jacket covering it,

I set my multimeter to the beep setting, and it beeped when i touched the two ends, so that means the fuse is good correct?

Also I have these two fuses and they both test good( i pulled them out of the assembly to test)
DSC01493.jpg





And what is the deal with this power switch?
DSC01484.jpg

When you push it in it turn the game on, but if you let go it pops back out and shuts the cab off.
If i pull it out it turns and stays on.
Is this the correct way to switch the cab on? that was the only power switch i found.
 
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when i first brought this home the picture did come up, only after i took the pcb out of the cab and then put it back in did it start doing this

Game pcb or monitor pcb ?

And what is the deal with this power switch?
When you push it in it turn the game on, but if you let go it pops back out and shuts the cab off.
If i pull it out it turns and stays on.
Is this the correct way to switch the cab on? that was the only power switch i found.

That's a safety interlock/service switch. It's working exactly as it should. when the back door is on it would hold the switch in to power up, when back door is off you have to pull the switch out in order to service anything/no power.
If you follow the lines that goes into that area, I'd bet you find a regular power switch. (maybe on top of the cabinet, maybe on the bottom)
 
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Game pcb or monitor pcb ?

The game pcb.






That's a safety interlock/service switch. It's working exactly as it should. when the back door is on it would hold the switch in to power up, when back door is off you have to pull the switch out in order to service anything/no power.
If you follow the lines that goes into that area, I'd bet you find a regular power switch. (maybe on top of the cabinet, maybe on the bottom)


I will look for one.


The spark has seemed to stopped after i did some adjusting on the power supply,

I have the 12+ at like 12.11 DC on my multimeter
but after adjusting the 12+ it throws the 5+ to like 4.64 DC

I am about to take a video and post what it is doing on the screen, hopefully that will help. its crazy, it goes through shades of blue, green, purple, and then it gets white, then it runs like this sweep across the screen like its trying to produce a picture.


I will post the video of this soon.
 
Well i traced the wire comming from the two fuse block by the service switch and there is no other on switch.

I took the front off and removed the marque, suprisingly the lights are just regular lightbulbs, so i switched both those, and voila I have lights on my marquee. Also there was only one speaker on the left, i think this is by design though, because i dont even see wires for the right one.

I wasnt getting any sound out of the existing speaker, so I wired up a new one, now i get static when i power on.
I tried the pot on the game pcb that controls volume and the static will just get louder. No game sounds at all.

I am really begining to think the power supply is the root of my problem, but then again I am only like 5 days into this hobby.
 
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