WG K4900 fuzzy picture?

Oh, ok so that glob on the corner is actually a pad thats supposed to be there? So weird they would do it that way through a huge hole and not just a normal pin.... On mine, the wire that attaches to the ground was just wrapped around a bare wire on the tube. Is there a better way to add it like with a plug end? Or is that jsut how it goes?

And Im probably just gonna do a cap kit on this and also replace C365, but what do I replace it with?
a higher value than 154 lol it's been a long time since I've changed a width cap

if you go on this page you'll see different values in action on a Moon Patrol (where the displayed image appears almost like a perfect square on an unmodified monitor)

strangely parism didn't have a 390 nF example, that's the stock value the K4900 would have come with. yours would match the 150 nF example in the pictures. I would thus try a 390 (or maybe it's 394) and that should tighten the picture up more. I have an APAR width cap kit at work that I can look at the sheet and maybe shed more light on the situation.
 
Looking at your pictures, I would suggest reflowing all cold solder /dried looking joints. The 4900 monitor is a real workhorse. That monitor can still work with more than half of the caps being bad. I would change all the caps before adjusting anything.

As far as which value width cap to change it to, once again, you can read about it here:


Make sure you use a 400V cap and not a 200V for that chassis (width cap). It even states it in one of the 4900 supplement manuals.

Unless you plan on keeping it Tekken, it's not a good board to use to adjust the monitor, in my opinion. From what I remember, in the Tekken test menu, there are all different kinds of color adjustments that maybe out of whack.
 
Oh so it is jsut trial and error then? Im so used to everything needing to be so specific I was thinking there would be a specific recommendation. I was also hoping to not have to buy a $20 set of which Ill only use one piece lol.

So what I have is a "154", and the higher the number the more it shrinks the image?
 
Oh so it is jsut trial and error then? Im so used to everything needing to be so specific I was thinking there would be a specific recommendation. I was also hoping to not have to buy a $20 set of which Ill only use one piece lol.

So what I have is a "154", and the higher the number the more it shrinks the image?
yes, if that monitor came from a Moon Patrol as an example it probably would've had the cap changed to a 154 to get it to fill out horizontally. 390 or 394 (I haven't made it to work yet to look at the APAR width cap kit sheet) would shrink horizontally yes
 
Oh, ok so that glob on the corner is actually a pad thats supposed to be there? So weird they would do it that way through a huge hole and not just a normal pin.... On mine, the wire that attaches to the ground was just wrapped around a bare wire on the tube. Is there a better way to add it like with a plug end? Or is that jsut how it goes?

And Im probably just gonna do a cap kit on this and also replace C365, but what do I replace it with?
I forgot to respond to this. I think you're talking about the CRT ground wires on the neckboard. I add solder here, and pull the wires off. I cut the exposed wire ends off, strip, and solder the wires back on. there's a reason for this, maybe not in your case, but there's a number of monitors where the wire ends are fraying and breaking off. if you lose the CRT ground connection to the tube you'll start getting arcs at the neckboard and they can potentially get a little violent. lol

also in my video watch the part where I start sanding the solder mask off on the ceramic resistors in the corner. I may have explained that I do that to build up more surface area for the solder to stick to. the stand up ceramic resistor in the corner you'll probably notice on your board is very dark brown from the heat, the fiberglass is super fragile here and people have broken that corner off. it's my theory that more solder area may help solidify that, but in the very least it will improve the solder connections a lot. yours in the pictures look bad.
 
Ya, I thi k ill redo that corner like in your video, it definitely looks kind of messy, just weird there no solder point or pin like in everything else, just a glob of wires lol

So I did actually realize that my plexiglass was pretty dirty and cloudy and when I took it off that cleared up some of the "bluriness". I think there's also maybe some modern bias going on and this is just what an older game looks like on a 19" TV vs a 42 1080 plasma lol

So I got tekken mostly dialed in besides the width, however there's a spot on the screen that never gets quite "red". It just stays kind of orange.
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It actually looks fine on all the other colors and even white seems pretty balanced.
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Is this a tube issue? Degaussing also didn't seem to affect much.
 
Another thing on this monitor, I plugged in a Pandora and get this slight wavy jiggly screen.


Its a similar pattern to the square on the test screen of the Tekken going through the big square with brightness turned down, but that one is stable and not moving.

Is this just a sync issue with different games, or is it fixable?
 
Looking at the first video during the loading screen with the hula wave on the right side of the screen, if you have not capped the chassis yet, I would do it. I bet you got some bad caps if measured with an ESR meter.
 
Looking at the first video during the loading screen with the hula wave on the right side of the screen, if you have not capped the chassis yet, I would do it. I bet you got some bad caps if measured with an ESR meter.
K4900s are amusing. they'll run bone stock still 40+ years later with no issue in commercial settings or they'll exhibit multiple cap related failures. I'm only really familiar with the bright diagonal lines at the top of the screen or the familiar bright/dark thing (which is going to probably be the 47 uf/160V B+ filter cap)

there's 2 distinct revisions of the K4900, one will have smaller heatsinks for the vertical transistors (older) and bigger heatsinks (newer). I'm not entirely certain if that's the breakdown for the different yoke pairings, it's been suggested here for a very long time the number of adjustment pots is the deciding factor. I've never had a deflection board/yoke mismatch before. but the reason I mention this at all is there will be a big cap toward the middle of the board on the edge closest to the tube, the older one will be a 2nd 47 uf/160V cap and the newer one will be 100 uf/160V. APAR only sells the K4900 kits with the 100 uf part and one day I just said F it and upgraded the cap and there were no murders or casualties after the fact. LOL

I might have taken pictures of the differences. I was surveying my pictures from Texas earlier, I did a lot there and got pictures of probably about 85% of what I did. I found a picture of how I sand the solder mask to make the solder area greater. I use a Craftsman rotary tool and sanding bit for this, and I also sand the resistor legs too. your solder will be much stronger doing this. if you look close you'll observe I took the width coil out too. that's another area I place emphasis on cleaning up. otherwise I add/remove/add solder to the yoke header pins and just add more solder to the degauss and signal header pins. I go in a circular motion around the pins to distribute the solder better.

k4900 sand.jpg
 
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So I got a cap kit and it has a 47uf 250v cap for c507, but I can't find c507 anywhere on here. It also isnt on the cap map I found. Does this one just not have it?

Edit: NVM, literally just found it as far as possible from the other 500s...
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