WG k4500 Help needed

ManiN

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So I have a WG K4500 that has some issues. The game is Big Event Golf. and should look like the good picture attached. I just put a cap kit on and re-flowed some solder at suspect cold/cracked joints especially at the pins for the daughter cards. I attached pics of the input card as this monitor was put in from a galaxian game by the prev. owner. I have suspect that there may be something wrong with the way the wiring was hooked up to this unmarked card. Notice only 4 pins used on the left side of the card... Since the cap kit and re-flowing, the monitor looks much better than to start, but still, I have the colors cranked up to look like the shots shown. Vert and hor adjustments are able to hold the pic still, but wont correct much better than that shown. Any advice, PCB maybe? Notice the guys pants are to the left of where they should be in the 'game over' shot. I'd like to save this monitor to use till I have some more cash later...

Thanks in advance!
 

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You have at least 3 problems that I can see from your pics.
  1. Your black level needs to be adjusted. It is the blue pot on the 3rd pic.
  2. Your brightness on your neck board needs to be turned down.
  3. Your H Hold needs to be tweaked a hair to straighten the picture.
 
You have at least 3 problems that I can see from your pics.
  1. Your black level needs to be adjusted. It is the blue pot on the 3rd pic.
  2. Your brightness on your neck board needs to be turned down.
  3. Your H Hold needs to be tweaked a hair to straighten the picture.

Thanks for the advice! I'll check those points tonight. I'll post what happens. BTW, I tried the cheap-o deguassing method of a soldering iron with little effect...
 
Thanks for the advice! I'll check those points tonight. I'll post what happens. BTW, I tried the cheap-o deguassing method of a soldering iron with little effect...

Your problems are simple adjustments required after a cap kit, and have nothing to do with degaussing at this point.
 
Well, I've messed around with adjustments including both purity and convergence. It just seems like the brightness / contrast is way off, but I am yet to find that adjustment anywhere on the chassis. The only one is the obvious adjustments for brightness and contrast a and a few others, but are clearly marked 'inoperative'. Not sure why they'd even include them...

Any clues?
 
An update:

I've been messing with convergence and purity and have gotten 'some' results, but still looks similar to the original posted examples, just a little straighter.

Here are some example screen shot photos from the internet to show comparison with the ones first posted. You can see it looks like there is just no white color whatsoever.

Any thoughts on this? It's frustrating for sure. My knowledge is limited so any help is great.
 

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You have at least 3 problems that I can see from your pics.
  1. Your black level needs to be adjusted. It is the blue pot on the 3rd pic.
  2. Your brightness on your neck board needs to be turned down.
  3. Your H Hold needs to be tweaked a hair to straighten the picture.

Again, the Black level is the blue pot in picture #3 & #4.
The brightness is a pot on the neck board.
 
Again, the Black level is the blue pot in picture #3 & #4.
The brightness is a pot on the neck board.

I've tweaked the black level with little change.

I still cannot find a brightness pot on the neckboard. I've attached a clip of the schematic for the neckboard section, and cannot find anything labeled "VRXXX" just in case.

I appreciate your help so far Dokert!

k4500_Neckboard.jpg
 
Well, for starters, your red is too hot. Turn it down so you don't see the red raster lines.

Next, if you notice, the picture is brighter on top than it is on the bottom. This is usually caused by a cap problem. Double check all your caps for polarity and good solder, and make sure all have continuity to the next part on each leg's trace.

Also, when you capped it, did you use the caps for the 4500, or did you use a 4600 cap kit?

You can try wiggling the interface card while watching the screen. if it gets better, pull the chassis and reflow the pins on both the chassis and the daughtercard...
 
Well, for starters, your red is too hot. Turn it down so you don't see the red raster lines.

Next, if you notice, the picture is brighter on top than it is on the bottom. This is usually caused by a cap problem. Double check all your caps for polarity and good solder, and make sure all have continuity to the next part on each leg's trace.

Also, when you capped it, did you use the caps for the 4500, or did you use a 4600 cap kit?

You can try wiggling the interface card while watching the screen. if it gets better, pull the chassis and reflow the pins on both the chassis and the daughtercard...

I've played with turning down the red, but doesn't increase white at all. It's really non-existant... The 'game over' should be solid white letters for example.

I capped it for a 4500 with a kit from Bob Roberts.

I noticed before any work, when wiggling some cards the screan would wig out, so I re-flowed all the pins, and that seemed to cure it. I'll look into the cap polarity and solder, but I paid pretty good attention when soldering, so I have a feeling it's maybe a bad leg?

Yes, I agree, the major issues are no white and half the screen has issues with brightness and allignment.

I suspect this monitor could be whacked out from a novice trying to adjust it before me. I also am a novice, but believe part of this repair will be un-f*cking their erronious adjustments. It was all whacked out with a fresh cap kit when I got it, and I re-did the cap kit with new to ensure reliable work.

Your help is appreciated.
 
Rather large update: After reviewing the schematic around the video interface card, I found that a key single wire was disconnected. It has been since I got the machine. I studied the schematic and plugged it in where it made sense, and bam! I've got my whites!!! So after that, a friend and I made adjustments and got it to a point of good color and the center being pretty well converged, but now the only remaining issue is that around the bordering edges, the colors are out of alignment. The 3 main color adjustments around the tube adjusted well to align most of the center area, but when I try to adjust convergence on say the bottom, top, right, or left... there is little to no difference. If anything, it makes the screen have a very slight wave with most of the adjustments. Almost like a sync issue. Are the pots bad / rusted / dirty? Should they be very significant in adjustment or only very minor?

I tried to do a proper convergence with a grid etc, but I cannot get my PCB to go into the grid mode as described in the convergence adjustment directions. Part of the problem is that it's a retrofit PCB into an older case and the service switch to initiate the grid mode is non-existent. I located the wire that is supposedly for the service mode on the wire harness and thought to ground it to make it 'switch' and it only added coins. That makes little sense as the coin wire is already hooked up.

Any ideas?
 
If it's out of convergence around all the edges, but not in the center, then I would suspect that the yoke is not seated fully against the tube/wedges....
 
If it's out of convergence around all the edges, but not in the center, then I would suspect that the yoke is not seated fully against the tube/wedges....

Hmmm ok, well, the situation on that is that the large winding I see around the tube (yoke?) has a plastic frame that appears to hold it from the outside and is stuck to the tube via sticky pads. These pads were delapidated and some loose when I first looked at it and this plastic frame seemed loose, hence a loose and out of alignment yoke. I jiggled it and found the yoke to be completely loose inside this frame. If I was to adjust the position of the yoke with this loose frame in re-sticking it, what is the best way to re-position it? It's hard to see if it's centered or not. Should I just turn it on and move it around till it looks right? Will I get shocked if I touch near it??? It seems once I stick it in place with new sticky pads, it wont move much.

Thanks for your insight!
 
You won't get shocked by touching the yoke while it's one, just keep your hands away from the anode cup and don't let your arms or hand contact the neckboard or chassis while reaching in.

Also, the new wedges you put it may be too close to center, holding it too far away from the tube. Unless the monitor is out on a bench, you'll probably need help (or a good mirror) to do this by yourself. Not only do you want the convergence right, but you don't want to end up with the picture angled...
 
Well, I've since positioned the yoke and have been adjusting purity and convergence again. I have been getting better luck, but I must say, this is a difficult task without a proper grid and either a mirror or a buddy. My cab has been converted and it seems they never hooked up the service switch wire. I read in my monitor directions (from a galaxian manual cause it has the only known monitor adjustment directions) to toggle the service switch until the grid shows then leave it switched. Well, my service switch is a yellow wire coming off the harness from the pin labeled service switch. You fellas know how this should be wired to get a grid up? I have no schematic for the PCB, just the pin labels. Game is Big Event Golf, non-Jamma.

So far I've just been using the picture of the game, but a grid would be way faster since it's still and not flashing from screen to screen.

All help is appreciated!
 
just ground that wire to trigger a service switch closure pulse. You could hook it up to a button or switch, with the other side connected to ground. I'm surprised there isn't one mounted inside the coin door...
 
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