K 7000 blowing fuse, all new parts.

z28dan

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Hi all, I just redid a k 7000 with new flyback and hot, all new caps and voltage reg.
Fire it up, and there is a short somewhere. It makes a little noise, then poof goes the fuse.
Followed the flow chart, Hot is good, diodes are not shorted, flyback is new.... end of the flow chart. I have looked the board over for obvious shorted traces, blobs of solder etc.
Nothing jumps out at me.
All caps are in correctly, I tried disconnecting the degaussing coil with same results.

I recently did a g07 that popped a fuse, and it turned out to be some kind of short in the tube. Hooked it to another tube and it works great. Any chance this tube is shot?

Any help or direction would be appreciated. Thanks
 
Real good chance the tube is causing the problem, i just put a couple 7000 tubes in the trash a few weeks ago with that exact problem. fire up your chassis outside of the monitor frame and hold the anode cup close to a metal part of the chassis frame for a second or two. If you see the light show and it doesn't blow the fuse, you've got a dead tube.
 
Hi all, I just redid a k 7000 with new flyback and hot, all new caps and voltage reg.
Fire it up, and there is a short somewhere. It makes a little noise, then poof goes the fuse.
Followed the flow chart, Hot is good, diodes are not shorted, flyback is new.... end of the flow chart. I have looked the board over for obvious shorted traces, blobs of solder etc.
Nothing jumps out at me.
All caps are in correctly, I tried disconnecting the degaussing coil with same results.

I recently did a g07 that popped a fuse, and it turned out to be some kind of short in the tube. Hooked it to another tube and it works great. Any chance this tube is shot?

Any help or direction would be appreciated. Thanks
You can also try checking C36, C37 and C38. You can also check D-18.

Here's a link to my thread where I had a similar problem.
 
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Yeh any one of those caps might be shorted.

If a short in the tube is suspected, connect it to a rejuvenator and test it. Some shorts can be repaired with it.
 
I just had a K7000 that would blow the fuse after about 30 seconds....it would also take out the HOT each time. Turned out D18 was slightly leaking....letting reverse voltage happen.

Edward
 
If you suspect a bad tube.... why not just fire it up without the neckboard connected to the tube ? Does it still blow the fuse ?
Leave the yoke and anode connected.

I'm more inclined to think something like C36 being shorted right behind the flyback.
 
no longer blowing fuse.

A little update, I replaced d-18,c-37,c-38(shorted) I checked the rest of the diodes and they tested good. replaced the voltage reg, now the fuse no longer blows, still no neck glowing , no high voltage. I went to shut it off and saw r-96 glowing red. I shut it down and checked it, r-96 is now open.
I'll try and do a little checking tomorrow any pointers where to look?
 
recheck your cap work.. amke sure the polarity is correct, make sure your solder didnt actually jump two traces it shouldnt have, etc..


its possible thertes something else evil going on here like bad tube bad yoke but without it in front of me i dunno for sure..
 
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