Wells Gardner 19K4626 - troubles

TracerBullet

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First, introductions!
I'm a product of the 80's
In the lost generation. Not quite X, not quite Y. The end of the latchkeys, the beginning of commerical ISPs.
I've been called Mr. Fix It (and given a T-Shirt to prove it).

I am maintaining a Ms. Pac-Man conversion in an original Pac-Man cabinet for my friends' bar, but I'm not very experienced with CRTs.

A few weeks ago the display would start good, but snap to a green overlay with lines showing vertical fold-over during warm-up.
I ordered a cap-kit and replaced the caps that I could find. (two were labeled with 5xx numbers while I only have a 2xx, 3xx, 4xx, and 6xx board).
I did not replace the resistor or the pot.

After the cap kit, there was no change in the display, except now there is no snap. It has the green overlay from the onset of the warm-up.

I researched this a bit more and found a suggestion to swap the green and blue feeds. I did this on the yoke (maybe on the CGA connection would have been better?). Now I have no picture. I'm guessing this was a horrible idea.

I'm about to order an LCD replacement, but i'd like to get this CRT working again.
All four of the boards are in rough shape. Is there any way I can get completely new boards for this thing? Even if I have to populate them myself, I can. If not, what is the best way to clean them up? With the LCD in place I'll have a lot more time to work, and better lighting to clean and reflow everything.
 
First, introductions!
I'm a product of the 80's
In the lost generation. Not quite X, not quite Y. The end of the latchkeys, the beginning of commerical ISPs.
I've been called Mr. Fix It (and given a T-Shirt to prove it).

I am maintaining a Ms. Pac-Man conversion in an original Pac-Man cabinet for my friends' bar, but I'm not very experienced with CRTs.

A few weeks ago the display would start good, but snap to a green overlay with lines showing vertical fold-over during warm-up.
I ordered a cap-kit and replaced the caps that I could find. (two were labeled with 5xx numbers while I only have a 2xx, 3xx, 4xx, and 6xx board).
I did not replace the resistor or the pot.

After the cap kit, there was no change in the display, except now there is no snap. It has the green overlay from the onset of the warm-up.

I researched this a bit more and found a suggestion to swap the green and blue feeds. I did this on the yoke (maybe on the CGA connection would have been better?). Now I have no picture. I'm guessing this was a horrible idea.

I'm about to order an LCD replacement, but i'd like to get this CRT working again.
All four of the boards are in rough shape. Is there any way I can get completely new boards for this thing? Even if I have to populate them myself, I can. If not, what is the best way to clean them up? With the LCD in place I'll have a lot more time to work, and better lighting to clean and reflow everything.
get learnt:
 
get learnt:
Before I spend an hour and a half watching a video on a monitor I've already disassembled and reassembled, is there a specific part of this video I should pay attention to?

I have pictures and a video, but it's going to be more that I can do tonight to get them into a format that's allowed to be uploaded here.
 
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Also found a diagnostics flowchart and a service manual to detail what the parts are.

I think I overlooked the 5xx board when I had it apart... oops.
 

Attachments

  • Wells-Gardner-K4600-Service-Manual.pdf
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  • K4600-Flowchart.pdf
    100 KB · Views: 1
you shouldn't be messing with the yoke wires to diagnose color issues. Those have nothing to do with color input and are for the horizontal and vertical orientation of the image on the screen. Swapping a vertical with a horizontal will damage the monitor.

You swap the color transistors on the neck board to check that kind of thing.

The green with raster lines sounds more like a shorted green electron gun to me though.
 
you shouldn't be messing with the yoke wires to diagnose color issues. Those have nothing to do with color input and are for the horizontal and vertical orientation of the image on the screen. Swapping a vertical with a horizontal will damage the monitor.

You swap the color transistors on the neck board to check that kind of thing.

The green with raster lines sounds more like a shorted green electron gun to me though.
you remove the green drive transistor entirely to rule out if it's bad drive circuitry or shorted electron gun.

and yes. I know the yoke wires are red blue yellow green... they have nothing to do with the colors. as has been noted. and I am reiterating.

you calling it a 19K4626 obviously doesn't make you more intelligent or even remotely enlightened on the topic.
 
you remove the green drive transistor entirely to rule out if it's bad drive circuitry or shorted electron gun.

and yes. I know the yoke wires are red blue yellow green... they have nothing to do with the colors. as has been noted. and I am reiterating.

you calling it a 19K4626 obviously doesn't make you more intelligent or even remotely enlightened on the topic.
It just means the sticker is still legible.
 
you shouldn't be messing with the yoke wires to diagnose color issues. Those have nothing to do with color input and are for the horizontal and vertical orientation of the image on the screen. Swapping a vertical with a horizontal will damage the monitor.

You swap the color transistors on the neck board to check that kind of thing.

The green with raster lines sounds more like a shorted green electron gun to me though.
Damage how?

The first thing on the flow chart is to check the fuse. This fuse is soldered to the main board and wrapped in a tube that was once clear before now being covered in a brownish goo. This just means I'll have to pull the monitor again to check/replace the fuse and anything else while I have access. I'd like to diagnose/replace as much as possible each time I disassemble the cabinet.

I have a VGA to CGA breakout board. Is there anything I need to know if I want to put power to the monitor outside of the cabinet?

Does anyone have tips on getting the lower left (as viewed by the gamer) mounting bolt into the frame without a second person?
 
Prefacing this by saying I'm not a monitor expert:

From the video it seems you have a shorted green gun in the tube like some above were saying. (All one color with raster lines)
Usually you'll need to use a rejuvenator to remove the short. If you don't have access to one @zenomorp recently showed how to diagnose and fix a shorted gun: https://forums.arcade-museum.com/threads/shorted-color-gun-solution.553184/

Beyond that I've read that you can place the tube face down on something soft and lightly but firmly tap the neck to dislodge crap, but that's not for the faint of heart so I'd probably leave that as a last resort.
 
Damage how?



I have a VGA to CGA breakout board. Is there anything I need to know if I want to put power to the monitor outside of the cabinet?
You most likely burned out some components in the vertical deflection circuit by swapping H&V yoke wires.

You MUST USE AN ISOLATION TRANSFORMER TO POWER IT.
 
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You most likely burned out some components in the vertical deflection circuit by swapping H&V yoke wires.

You MUST USE AN ISOLATION TRANSFORMER TO POWER IT.
Thank you! I did see that sticker around the power cable before it fell off. Wasn't sure if that was just for normal use or also service.

In fact every sticker is no longer "sticky". That's another thing I'd like to do while I'm poking around in here.

Does anyone sell a labeling kit?
 
Update:

The F601 fuse was blown. Not fun to change. Soldered to the board through aluminum standoffs, wrapped in a gooey tube. I desoldered at the board, the ends of the fuse seemed impossible to reach.

The fuse replacement gets a picture again, but it's just a green horizontal line.

I've replaced the CRT with a drop-in LCD and a CGA to VGA conversion board. I can take this box to a proper workbench now.

Thank ya'll for the help. I'm sure I'll have a few more questions as I work on it.
 
Update:

The F601 fuse was blown. Not fun to change. Soldered to the board through aluminum standoffs, wrapped in a gooey tube. I desoldered at the board, the ends of the fuse seemed impossible to reach.

The fuse replacement gets a picture again, but it's just a green horizontal line.

I've replaced the CRT with a drop-in LCD and a CGA to VGA conversion board. I can take this box to a proper workbench now.

Thank ya'll for the help. I'm sure I'll have a few more questions as I work on it.
welcome to vertical collapse. have you properly serviced a K4600 yet?
 
On a bench? No.

Only in a bar with the cabinet containing both my only signal and power supply.
 
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