A cap that was missed in the B+ area? Where?

Steverd

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Still working on my WG7901 Chassis. A full time monitor repair person told me that it looks like a cap that was missed in the B+ area. Wait what? Where's that? I have the Layout and schematics here and can't find that.

Help please!
Steve
 
Kind of an odd comment from a full time tech.. Why wouldn't he just point out where?

Look for the B+ pot, see if there are missing caps.. Look on the neck pcb, is there a missing cap? Did you remove all the caps then start to replace, or was it just missing? Do you have a cap left in the kit?
 
There are 17 polarized caps on the chassis (not counting the filter cap), 18 if you have the neckboard cap, and 20 if you have the little board that mounts on top of the left wall. Maybe 22 if you have a rare 27" version with a pincushion board.

Anyway, count the 17 on the main chassis (+ 3 bipolar caps and 1 filter cap for a total of 21) and see if you're missing one. If so, lets see a pic of the chassis...
 
There are 17 polarized caps on the chassis (not counting the filter cap), 18 if you have the neckboard cap, and 20 if you have the little board that mounts on top of the left wall. Maybe 22 if you have a rare 27" version with a pincushion board.

Anyway, count the 17 on the main chassis (+ 3 bipolar caps and 1 filter cap for a total of 21) and see if you're missing one. If so, lets see a pic of the chassis...

I count 21 with the 3 bipolar caps and the filter cap.

capkit-4.jpg

Thanks for your help, I think that there's AC leaking onto the DC.
I'm going to send this chassis out to an expert. I think I've done all of the damage I can on this one!

Steve
 
Why would you think that?

And I'd cap it and go over everything in the K7000 sticky if I were you...
 
Why would you think that?

And I'd cap it and go over everything in the K7000 sticky if I were you...

Thanks Modessitt, I always appreciate your help!
I did replace all of the caps, all 21 of them. The colors where better, but I still had the jailbars. I also have ground from the monitor frame, to chassis all the way to the power plug ground. WG tech support thinks it could be the flyback.

I'll recheck the 7000 sticky.
 
I did replace all of the caps, all 21 of them.

Before or after that pic? The caps in that pic haven't been changed. Look at all that dust and dirt on #1.

The colors where better, but I still had the jailbars. I also have ground from the monitor frame, to chassis all the way to the power plug ground. WG tech support thinks it could be the flyback.

If the flyback has white knobs or little cracks around the knobs - or both - it should be replaced. Don't think it's causing your jailbars, though.

I'll recheck the 7000 sticky.

Pay attention to the part about bad traces...
 
Before or after that pic? The caps in that pic haven't been changed. Look at all that dust and dirt on #1.

If the flyback has white knobs or little cracks around the knobs - or both - it should be replaced. Don't think it's causing your jailbars, though.

Pay attention to the part about bad traces...

Yeah, that was a before image, should have said that.
Don't know why WG support would suggest the flyback, I mentioned that to Bob Roberts, he didn't think that sounded right either. I was thinking are they trying to sell me a flyback???? I would get it from Bob Roberts though.

It could be bad traces, or a cold solder joint I didn't see.
Seems like I've checked continuity between 100s of points.
Mainly I was worried about bad solder joints, I can tell the board had work done to it board.
 
Reflow the solder at ever pad! Even the neck pcb.. Replace the fly, as it's cheap and I'd bet the original one has hairline cracks..
 
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