Want to buy chassis/yoke but can't identify

tom11011

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Hi Group.

I have a pacman arcade that has a K7000a chassis mounted to a 4900 style crt.

I am told that the monitor is the original kind for pacman, but the chassis is not. I am working with someone here to get a rebuilt 4900 chassis, but the yoke that is on it cannot be identified by the ohms resistance and he doesn't have a yoke to go along with the rebuilt 4900 chassis.

If anyone can help me identify the yoke, would be much appreciated.

I was told to measure the ohms resistance on each of the the yoke pairs but the readings apparently don't conform to either the k7000a or the 4900.

red and blue of 7-9

and

yellow and green of 17-22

Also, here is a few pics of the cabinet as well.

http://www.avulant.com/1.jpg
http://www.avulant.com/2.jpg
http://www.avulant.com/3.jpg
http://www.avulant.com/4.jpg
http://www.avulant.com/5.jpg

Thank you.
 
No need to login. It's not a page per say, just a jpg file. Not sure why you can't access, maybe someone else can break the tie here.
 
It has a unique URL, hence I called it a page.

I just tried to access it from two other networks and I still can't get to it. I can not get to avulant.com from any access point.


By the way, hosting pictures on KLOV is the best way to get help from the members here. I assume it is because of ease of access for the pictures.
 
Don't know what to say, somehow it must be blocked on your end as the site is up and functional across the internet. Are you behind some kind of site blocking mechanism that somehow sees it as a threat?

Goto a proxy server and have a look at the images from there, this site will fetch them for you (www.ipconceal.com)

Thanks for your help.
 
Hi Group.

I have a pacman arcade that has a K7000a chassis mounted to a 4900 style crt.

I am told that the monitor is the original kind for pacman, but the chassis is not. I am working with someone here to get a rebuilt 4900 chassis, but the yoke that is on it cannot be identified by the ohms resistance and he doesn't have a yoke to go along with the rebuilt 4900 chassis.

If anyone can help me identify the yoke, would be much appreciated.

I was told to measure the ohms resistance on each of the the yoke pairs but the readings apparently don't conform to either the k7000a or the 4900.

red and blue of 7-9

and

yellow and green of 17-22

Also, here is a few pics of the cabinet as well.

http://www.avulant.com/1.jpg
http://www.avulant.com/2.jpg
http://www.avulant.com/3.jpg
http://www.avulant.com/4.jpg
http://www.avulant.com/5.jpg

Thank you.

You sure about those yoke measurements? Especially the horizontal (red blue).

You may be able to use that yoke with a 4900 chassis, if you want. There are some useful notes here, from JROK:

http://forums.arcade-museum.com/showthread.php?t=249008

But it might be a better idea to get your hands on a 4900 yoke. Less work.

Still, make sure you re-measure the impedance in your yoke windings. I'd be willing to bet that the yoke you have on there is the original one from the K4900 chassis.

The 4900 yoke should see around 3 for the horizontal and 35 for the vertical.

See here for reference:

http://junknet.net/donor-tvs
 
Yep, I want all original back in there. If its a 4900 yoke even better.

The person selling the chassis doesn't have a yoke.

I'll re-measure.
 
Pictures show up ok for me. What are the part numbers on the yoke that is on the tube now?

Good call, Ken.

To the OP: here's an excerpt from a post that Steve Wingert (Modessitt) posted a couple years back when I was doing some adjustments on a 4900 that I was working on:

Check the number screened on the back of the chassis. It will say:

DBQ
2061433-xxx

If xxx = 023, then you have an early version chassis and must match it with a yoke that has either of the following numbers on it:

2021111194
2021111201

If xxx = something else (like 034, 040, 057, etc), then it is a later series chassis and must match with a yoke that either of the following numbers on it:

2021111258
2021111264

If you mismatch a chassis and yoke, you will get foldover that cannot be fixed or adjusted out.

Here is the service bulletin that was put out about it...

If your yoke has one of those numbers on it, then it's a 4900 yoke. Early version or late version depends on the numbers you find.

Once you know what kind of yoke you have, then we can source the proper chassis for you.
 
1.jpg
 
The K7000a and 4900 used the same style CRT.

This is incorrect. The K7000A tube has a CR-31 neck, while the 4900 has a CR-23 neck.

Regardless, it looks like the yoke is a standard K7000A yoke and chassis. Probably someone just swapped a tube/yoke/chassis into an old 4900 frame so it would fit properly. Happens all the time. Unless you find a label on the yoke somewhere with a number matching what STG posted from me above, it's most likely NOT a 4900 yoke...
 
This is incorrect. The K7000A tube has a CR-31 neck, while the 4900 has a CR-23 neck.

Regardless, it looks like the yoke is a standard K7000A yoke and chassis. Probably someone just swapped a tube/yoke/chassis into an old 4900 frame so it would fit properly. Happens all the time. Unless you find a label on the yoke somewhere with a number matching what STG posted from me above, it's most likely NOT a 4900 yoke...


I have never pulled apart a 19" K7000a (I don't rebuild the K7000a models, I just use them for parts) with the smaller neck. I didn't know they even existed since the only small neck K7000's I have ever seen were standard res 19" WG models and 9" models.
 
I have never pulled apart a 19" K7000a (I don't rebuild the K7000a models, I just use them for parts) with the smaller neck. I didn't know they even existed since the only small neck K7000's I have ever seen were standard res 19" WG models and 9" models.

Hmm, and I rarely if ever see a 10-pin version - although I know they exist...
 
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