25k7191 k7000 Flashing

waltervan

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I have a MK4 machine I picked up last month with a DOA monitor.
I ordered and installed
Flyback
cap kit
R103 2.7 Ohm 7W Resistor <--- Old one was open
560uf200v B+ filter
I now get a very quick white flash "Looks to be only around the edge" Is this whats they call lightning bolt effect? I have checked the game with another monitor and all was good.
I have read the sticky post about the K7000 but still not sure.

Thanks
Walter
 
What exactly are you getting on the screen? Only one white flash, then a normal picture, constant white flashing? A little more explanation will help us help you.
 
Upload it to YouTube then embed it here. if you can't figure out how to embed, just put the link here...
 
If you replaced the flyback, you do know that both the "Screen" (coarse brightness) and "Focus" controls will need to be adjusted?
 
I would start by checking the B+ on it and go from there. Being that R103 was shorted open, you may have other issues that are causing your problem. I recently fixed a 25k7000 that had no pic, no B+, and shorted R103; but the HOT and voltage regulator were also bad.
 
what was with the loud snapping??? are you sure the anode wire is secured in the tube, and are you sure you hooked the neckboard ground back up to the tube?
 
I thought the "click" was him pushing buttons on his camera.

Actually, that quick flash in the corner almost reminds me of those monitors that have sync issues and other problems that cause the image to be way off the screen, with only brief glimpses of something on the edge. If it repeats, then it's not in shutdown.

But - a B+ measurement may tell us something...
 
I thought the "click" was him pushing buttons on his camera.

But that "click" corresponded directly with the flash on the screen.

Hmmm.....

Might want to take a look at whats going on on the backside (chassis) with the lights off and see if there is an arc of sorts going on.

Does the neck glow come on and stay on ?

Like cadillacman said, check that the anode lead is secure.
Also make sure all grounding straps are in place around the tube.
 
what was with the loud snapping??? are you sure the anode wire is secured in the tube, and are you sure you hooked the neckboard ground back up to the tube?

The click was the switch on the out let I was using.
 
But that "click" corresponded directly with the flash on the screen.

Hmmm.....

Might want to take a look at whats going on on the backside (chassis) with the lights off and see if there is an arc of sorts going on.

Does the neck glow come on and stay on ?

Like cadillacman said, check that the anode lead is secure.
Also make sure all grounding straps are in place around the tube.

I was going to try it in the dark but got called in to work just after taking the video ill try that this weekend.
 
You are using an isolation transformer correct? I'm sure if you weren't you would be blowing fuses but it doesn't hurt to ask. You didn't say what other type of monitor you used to test it with.
 
mk4

My first thought was if it is a dedicated mk4 that it might not have a isolation transformer in them as they at that time, were using u2000,u5000 which did not use a iso.
Check the cabinet for a iso.
 
My first thought was if it is a dedicated mk4 that it might not have a isolation transformer in them as they at that time, were using u2000,u5000 which did not use a iso.
Check the cabinet for a iso.

NBA Jam cabinet
yes it has an isolation transformer
 
You are using an isolation transformer correct? I'm sure if you weren't you would be blowing fuses but it doesn't hurt to ask. You didn't say what other type of monitor you used to test it with.

I tested the board on a 19K7901 monitor
 
I think I may have found a few problems
1. Width coil adjustment screw is all but destroyed
2. I think its called Lin Coil located between C56 & C38 is broken almost off.

I know where to get the width coil but cant find the other one I may have the wrong name
 
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