K7000 problems

Raab

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Well first of all it could be a pcb issue so bare with me. The exact model is 25k7190 with a Zenith tube. Both the pcb and monitor get the correct power. The game is also jamma Konami Racin Force. The monitor doesn't turn on and I hear no sounds from the speakers :(. First I checked the power and both are correct. The marquee light and coin door lights both light up also. I checked the fuse on the monitor it was blown so I replaced it fired it up and it blew again. Is there a fuse on the board because I couldn't find one? I noticed when i was checking the volts from the jamma connector that pin 4, on the parts side, was getting hot very fast seamed like it could be shorting. That wire only runs from the power supply. I took the connector off and the board has a nail tip size burn on the pin.

Any troubled areas I should start? I read that the flyback and/or hot could be bad but the board keeps me wondering.

Update: Thanks to Cadillacman's sticky I checked the flyback and noticed it has a hairline crack and looks like its fryed in the middle. Would this cause the monitor to be dead?
 
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Well, it sounds like you have two problems - a dead monitor and an inoperable board (possibly due to bad power from the power supply). Since this is the monitor section, we'll concentrate on that. Once you have it working, create a thread in the Repair section if you need help getting the game playing.

Okay, the K7000 monitor will power up regardless of whether the board works or not - if it's functional. You'll be able to turn up the brightness at the flyback and see raster if it is on. The fact that you are blowing the fuse is indicative of a short somewhere on the chassis. The small crack in the flyback COULD be the cause if you are seeing it arc out of that crack, but I've often seen those small cracks around the knobs on fully functional K7000's. I doubt it is blowing your fuse, but I'd replace it anyway since the cracks can cause issues with your brightness and focus levels.

When I see a K7000 chassis that is blowing the fuse, I typically find the cause to be one of these (in order of likelihood):

a) IC4 - VR (voltage regulator)
b) C38 - horizontal width cap
c) D20 or D21 - rectifying diodes near filter cap
d) D18 - diode near yoke connector
e) Q11 - HOT (horizontal output transistor)
f) C36 - critical safety cap
g) blown cap - look for caps with domed tops
h) dag wire not connected while powering it up
i) bad flyback - normally seen arcing

You may have more than one of them bad, as one failing part can sometimes cause others to fail with it. Once you get the fuse to stop blowing, you may have other issues to deal with. The chassis probably has old caps and lots of cold solder or burnt traces that need repair, so pull it out and check the components I listed above. While doing that, replace the flyback and put a new cap kit in. Check over all the areas mentioned in that sticky for bad solder or broken traces while you have it out.

Once done properly, a K7000 can be one of the best monitors you have...
 
Thank you Ill start testing and replacing. Ya it looks like it should be easier to work with that the 4600. More space to move. Also I noticed thin bare wire on the side of the tube that looks like it snapped. I assume it should be reconnected correct? I can post pictures when I get home if needed!
 
pictures are worth a bijillion and one words. i'd figure out what that snapped/snipped wire is that's not connected (it's prolly just a ground tho), and often just jiggling around wires could tell you a lot while it's powered on. if it's not powering up i'd concentrate on the 2 wire (black and white) molex by the flyback and make sure you have voltage there as well as no shorts. (you said you have good voltage tho when you tested so try the jiggle effect first lol).

the fact that the speakers aren't coming on has me thinking it's something else tho. you should still have sound if the monitors bad (hence the term "playing blind").

regardless if your flyback is cracked, i'd do a full cap kit and flyback, maybe replace the hot while at it.
 
Okay here a picture of that wire. Thanks for the help/advice. Any other pictures needed or wanted just let me know. Also how should I reconnect it? It seems to not have enough slack but on the other side its crossing with the same wire on that side. Should I untangle it and solder it together? or does it have to be tight to the tube? Also noticed this wire it cut and I cannot find a place for it to go.
 

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2nd pic looks like -sync if it's the wire that's bent upwards. not quite sure of pic 1 (maybe part of your degaussing coil? (i'm judging by the k7191 manual). One of these guys will chime in and know if you can unwind it or not. I'm still green when it comes to this stuff.
 
Okay here a picture of that wire. Thanks for the help/advice. Any other pictures needed or wanted just let me know. Also how should I reconnect it? It seems to not have enough slack but on the other side its crossing with the same wire on that side. Should I untangle it and solder it together? or does it have to be tight to the tube? Also noticed this wire it cut and I cannot find a place for it to go.

The first picture is for the dag wire, that is actually supposed to connect to your neckboard. The white wire that's sticking up is actually a jumper for the synch wire, it needs to be spliced to the white wire next to it.
 
The dag with is connected to the ground on the other side but it looks like it snapped apart on the picture side. Does this game require the sync because it looks like it doesn't go anywhere.
 
yup (i believe so), but that's only going to fix an issue you would have had once the monitor will power on. (it shouldn't effect anything since the monitor isn't powering up and this only deals with the picture).

hopefully modessitt see's this as i could be wrong, as i said i'm still kinda green when it comes to monitors, try and track down the manual for your specific model (as i mentioned i'm referring to the 7191 manual which might be different tho i doubt it).
 
For JAMMA, you need to remove that sync wire from pin 9 of that video connector and only have it connected to pin 10.

And that other wire near the corner of the tube - what's on the other end of it?
 
The bare wire on the tube is connected to the ground on the other side of the tube. The bare wire is just tucked behind that grey wire which I think Modesit thought it was connected to. Did you mean the what is the grey wire connected to? So I should cut that second to last white wire and wire it to the last one?
 
So i noticed today that that white sync wire is connected to both of the pins. That disconnected wire is actually the same wire wrapped around the back and through the other pin. So ill leave that alone and take a look at the things Mod said.
 
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