Dantebean
New member
What is the location of this cap. I have the problem too!!!
Another K4600 focus problem...
- Thread starter modessitt
- Start date
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modessitt
Volunteer: Encyclopedia Submission Moderator
Dantebean
New member
Thank you sir
roburt
New member
Yes, thanks for the pic. I still haven't done mine. In fact, I can't even get to the machine right now as it's buried behind tons of stuff. Hopefully by June!
sk8ersublime
Well-known member
I am working on a k4700 with the same issue. I swapped a flyback from a 4600 but I can't get the picture to focus and I'm getting arcing in the neck socket at the focus pin when I turn the pot. I just swapped this cap with a 100pf 12KV...no change in the focus.
Any ideas?
Any ideas?
If you're getting arcing in the neck socket.....that's your problem. The focus goes through a spark gap inside the neck socket. Moisture's gotten inside and caused corrosion. I've seen this a few times over the years.
Edward
sk8ersublime
Well-known member
Hmm...yea when it arcs the screen gets clearer as its popping and arcing.
Anyway I can fix this? I already took apart the neck socket and I didn't see anything looking corroded. I worked on this with DogP as well last sat. Maybe he can add to my statement in this thread if he sees it?
You cracked the plastic open? Was the little metal "thingy" (disc and wireform...this is the spark gap) still present on the focus line? If not gunky, maybe it's bent out of position....
Edward
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modessitt
Volunteer: Encyclopedia Submission Moderator
I'd pull a donor socket off a parts board or a TV neckboard and replace it...
sk8ersublime
Well-known member
Got an extra CR25 neck socket laying around? 
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modessitt
Volunteer: Encyclopedia Submission Moderator
Got an extra CR25 neck socket laying around?
I think I have a 4700 around somewhere, but no, probably not...
sk8ersublime
Well-known member
Yea I desoldered the neck socket from the board, and I took the screws out to access the insider of the neck socket. The ring was there and appeared to be ok, I didnt know what it was for to be honest, but I left it alone.
When I put the socket back on the neck board, and powered up, it was arcing like crazy at the focus pin and out of focus still. I desoldered the spot where the ring pin grounds to the neck board and the arcing stopped, but I have the same focus issue. I am guessing it has to do with this ring or the socket.
Did you clean the pin on the tube and socket in the neck? I suggested using some silicone caulk to insulate it so it couldn't spark, though maybe that's not a good idea if it's in focus after it arcs (lower voltage), and can't focus if it's not sparking. If that's the case, maybe your focus voltage is simply too high, causing it to arc (by design), and can't adjust low enough.
You replaced the flyback with a K4600 fly, right? Did you check part numbers to verify that they're the same? It's possible that the 19" tube needs a higher focus voltage than the 13" K4700.
DogP
You replaced the flyback with a K4600 fly, right? Did you check part numbers to verify that they're the same? It's possible that the 19" tube needs a higher focus voltage than the 13" K4700.
DogP
I just took a look at the manuals... it looks like they're possibly different parts, though maybe compatible:
K4600
297X2000-072
K4700
200X9830-108
Anyone successfully swapped them? Did the old fly arc in the neck before swapping... or did you never see it function correctly?
DogP
K4600
297X2000-072
K4700
200X9830-108
Anyone successfully swapped them? Did the old fly arc in the neck before swapping... or did you never see it function correctly?
DogP
sk8ersublime
Well-known member
That might be the problem...
The part numbers were different, but the ohms were the same so I figured I would give it a try.
The original fly was arcing right where anode cable comes out of the fly. The monitor had such a crappy picture on it before I have no idea if it would focus or not as it was very dark.
I capped the monitor and swapped the fly then noticed all the arcing at the focus pin. Ill see if Rich still has the old fly laying around, then I can silicon it and see if I can focus....
joseph77
Well-known member
Bringing this up to see if anyone knows where I can get some of these and not wait 14-17 weeks. I do not have any other 4600 chassis' to take it off of.
sk8ersublime
Well-known member
I bought mine on eBay.
Peale
Active member
I fixed a 4600 the other day that had some arcing around that capacitor. But, otherwise the monitor was operating fine. I removed the electrical tape that was covering it (why is it on there?), unsoldered the focus wire, clipped it back, restripped, and resoldered it all together. The arcing stopped.
Quattrohead
Member
What happens if you remove the tape and give the cap a good cleaning or just remove the capacitor itself ?
Unsolder it from the focus pin end, do not clip it as the sharp end will encourage arcing too.
Unsolder it from the focus pin end, do not clip it as the sharp end will encourage arcing too.
joseph77
Well-known member
You wouldn't happen to have the link to who you got it from would you?
