common k7000 issues - common repairs

And what is up with the funky ass shielding on the black wire going from the flyback to the neckboard? Is it wax? Plastic? Transparent Aluminum?? I had to melt it off after attempts w wire cutters and a utility knife failed. It was like working on a recovered part from Roswell..
 
And what is up with the funky ass shielding on the black wire going from the flyback to the neckboard? Is it wax? Plastic? Transparent Aluminum?? I had to melt it off after attempts w wire cutters and a utility knife failed. It was like working on a recovered part from Roswell..


No idea what you're talking about...
 
No idea what you're talking about...

There is a black wire running from the flyback to the neckboard, specifically to the end of the part of the neckboard that hooks to the tube. You have to cut that wire when replacing the flyback, as one wire from the flyback is the red voltage wire running to the neckboard, the other is a black wire that runs to the base of that neckboard connector. When I cut that wire to splice in the new flyback, there is the black outer casing, then some clear-plastic-wax whatever that protects the metal wire core. That is the shielding I couldn't get through without FIRE! :D
 
There is a black wire running from the flyback to the neckboard, specifically to the end of the part of the neckboard that hooks to the tube. You have to cut that wire when replacing the flyback, as one wire from the flyback is the red voltage wire running to the neckboard, the other is a black wire that runs to the base of that neckboard connector. When I cut that wire to splice in the new flyback, there is the black outer casing, then some clear-plastic-wax whatever that protects the metal wire core. That is the shielding I couldn't get through without FIRE! :D

I want to see a pic. The flyback should only have three wires coming off of it - anode wire, focus pin wire, and G2 wire that connects to a pin on the neckboard.

Unless you have one with a brightener (white blocky thing), or perhaps you actually have a K7000A?
 
Could you be talking about the focus voltage wire? If so, that connects to the tube socket on the neckboard. You don't cut or splice that wire. It carries 8,000 volts in operation!

The focus voltage wire connects to the tube socket in three different ways depending on the particular socket that was installed on the neckboard.
 
I want to see a pic. The flyback should only have three wires coming off of it - anode wire, focus pin wire, and G2 wire that connects to a pin on the neckboard.

There were only 2 wires on the original flyback, a red wire, and a black wire. The red one had the connector that goes to the pin on the neckboard for voltage, and then the black wire which went to the neckboard location I have described. Below are pics:

(pic 1, old flyback wire next to its counterpart on the neckboard)
(pic 2, new flyback wire next to its counterpart on the neckboard)
(pic 3, just a general shot of the chassis)

PS please reply back ASAP, I'm a nervous friggin' wreck that I cut the wrong wire now thanks to you guys :(
 

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Ah, you have that socket. Well, you can solder the two ends together with heatshrink around it. It will work...
 
Not if it's soldered.

Don't worry about the voltage through it affecting the heatshrink. I've used heatshrink on a broken anode wire (23000 volts) with no problems...

Yeah it aint ideal but it works. If your really worried, slide several pieces of heat shrink over the wire starting with small diameter and get a little bigger a little bigger so you shrink layer upon layer if that makes sense so when you're all done, you have a nice thick coating.
 
I need some clarification in all newb terms if possible. My horizontal size is to big by 3-4 inches on both sides. From what I've read the horizontal size doesn't fix this but instead I need to switch out a certain capacitor. Is that correct and if so can you point out a specific one for me. I've got help from an electrician so If the only way to explain is in technical terms I can have someone translate for me. Thank you for any help much appreciated.
 
Are you working on a 19" or 25" monitor.

You guys need to try to adjust the horizontal width coil. Heres a little more info about width coils: http://www.therealbobroberts.net/wc.html

If you cant adjust this issue out, then you do need to swap caps untill you get the size right.

If you have any other questions, please feel free to ask!
 
I need some clarification in all newb terms if possible. My horizontal size is to big by 3-4 inches on both sides. From what I've read the horizontal size doesn't fix this but instead I need to switch out a certain capacitor. Is that correct and if so can you point out a specific one for me. I've got help from an electrician so If the only way to explain is in technical terms I can have someone translate for me. Thank you for any help much appreciated.

C38 is the width cap on the K7000. Larger value means smaller picture. Lesser value means larger picture...
 
BTW - this past week I ran into something Ken has mentioned in the past. Brand new flyback installed with a rebuild, and it kept blowing the HOT. The old flyback did not (but had other issues). Even though my ring tester seemed to indicate it wasn't bad, I lost 4 HOT's to it. Ordered another new flyback (from the same source as the other) and it works fine now...
 
Thank you very much for the assistance. I'm going to give bob roberts a try and change out that specific capacitor and see what happens.
 
this is my circuit board on my new Neo-Geo MVS-4 with the K7000 Monitor. The monitor works great except that it's 4 inches wide on each side. I know what I have to do to change that but look at the stuff oozing out of the big capacitor in the top of the left. Do you think that effects anything?
 

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Ran into this again today, and although I mentioned it somewhere here, I'm too busy to go find it now.

Chassis Model - K7000

Symptom - Dead. No neck glow or HV. In HV shutdown.

Troubleshooting - New cap kit and flyback had been installed. No bad parts or cold solder joints or broken traces found. On a previous repair with a similar issue, I had found a reference online as to C36 (the critical safety cap) being out of value, causing the chassis to be in HV shutdown. The proper value is supposed to be 6100 picofarads, which is usually indicated on the cap by .0061 or 612. Checking C36 on this chassis showed the number to be 432 - or 4300 picofarads (same as with the previous repair). This was a factory installed part (and the chassis powered up with the old flyback), so this was not a user-install error.

Solution - Replaced C36 with the proper 6100pF cap, and the monitor now works.


I'm not sure why the 4300pF cap works with the old flyback, but not with the new flyback. Perhaps the new reproductions have a slighlty different tolerance window that requires a much more specific value on C36 than the original flybacks used. But this is worth checking if you have done everything else and still have a dead chassis....

HOLY BATMOBILE.

O.K., I've got a K7000, same thing. HV shutdown, everything looks good, recapped, new (er) looking flyback, replaced Hot, replaced Voltage Regulator, etc. (I think this may have more to do with the Voltage regulator being new now than anything, but I digress).

HV Shutdown. Saw your post. This was a newer one with C36, AND C69. C36 was .0036, C69 was the usual 6100pf. Upon comparing THIS board with an older... the only difference in this and the 4 legged version, was that they used two caps. The original C36 was 6100, but now they've got two in there. I'm sure it worked that way perfectly originally... this has what appears to be a newer flyback, I didn't install it, but I get the idea that somebody did, got disgusted that it didn't fix it, and left it in there. Anyways.

I cut C36 out, and simply jumpered the trace from C69 over to where C36 was. The other end was already tied together by the traces. Basically, I connected the two pins together like the 4 legged cap would do, leaving the 6100pf still mounted in C69, C36 empty, and a small jumper to connect it over to C69.

Fired right up! I've got a Vertical problem now, but this thing was sitting pretty at 165 v for the last two days, and now I've got a perfect 130.
 
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