K7000's built by Zenith

[Kevin Mullins]

Got a box full of monitor parts and chassis that I assume all need some form of repair the other day.... started kinda sorting through them and realized there are at least four of these K7000's that were built by Zenith.
http://www.therealbobroberts.net/7000z.html

Looks quite like the typical K7000's for the most part.

Had never messed with one of these.... are there any quarks or known issues with these versus the typical P538 version ?

They all "look" good.... not burnt up or anything.
So I was just curious about them before I started poking around them to see if they'll be of any use to me.

[Kevin Mullins]

Read a post from Ken over on another forum about the flybacks being obsolete.
So that's a kicker right there.

[Ken Layton]

The flyback was special to the Zenith made version and is NOT available anywhere. Rest of the chassis is a standard k7000 and uses standard k7000 capkits.

[Kevin Mullins]

Good to know. 

Glancing at them I thought they looked pretty much the same to the standard K7000, aside from that funky flyback setup.

I'll have to throw a couple together sometime and see what happens.

I'm assuming they work with the standard K7000 yoke then ?

[Rickn]

Not that it matters much, but the K7000 was not made by Zenith,

It is still a Wells. The tube itself was made by Zenith, in some cases it will be branded with Rauland ( a sub of Zenith) The Flyback will be different in order to match the Zenith's tubes High Voltage, Focus and other characteristics.

Rick Nieman
Rick@niemandisplays.com

[ken_cinder]

Not that it matters much, but the K7000 was not made by Zenith,

It is still a Wells. The tube itself was made by Zenith, in some cases it will be branded with Rauland ( a sub of Zenith) The Flyback will be different in order to match the Zenith's tubes High Voltage, Focus and other characteristics.

Rick Nieman
Rick@niemandisplays.com

You sure about that? My 25" Zenith uses a K7191 WG "P538" Chassis, and the flyback on it looks the same as other K7000s, and obviously not like the one pictured.
I think the one here, is not made by WG by the sounds of it.

[Ken Layton]

The Zenith version is a K7000A.

[Kevin Mullins]

But the chassis itself was actually manufactured by Zenith ?

I know it's a "Wells Gardner" monitor, just clarifying who built this version of chassis.

[qrz]

for what it is worth , Zenith yokes and flys use a 95 prefix number ( 95- xxxx-xx )
tv "modules" are  9-xxxx-xx. lower numbers on the OLD stuff.....


qrz

[hatrick]

Kevin, I just PM'd you regarding the Zenith K7000a.

Thanks,

[Kevin Mullins]

Yup, ya most certainly did .... 

Just wanted to add a bit more information I found courtesy of Mr. Ken Layton.

info on the zenith K7000A chassis as provided by Ken Layton:


Around 1990 or so Wells-Gardner was getting so many orders from game manufacturers that they were falling behind in production. The k7000 was their most popular model at the time for arcade video games. So they subcontracted with Zenith Electronics for Zenith to build the k7000 MAIN circuit board and NECK board (but not the remote adjustment board). This became known as the "K7000A" chassis. It did not have the usual "P447" or "P538" numbers silk screened on the circuit board like the genuine Wells-Gardners did. Instead the main board is silk screened 204-2205-07 and the neckboard is silk screened 204-2203-02.

The easiest way to identify this version is that there are TWO PINK wires going to the suction cup whereas the standard Wells-Gardner k7000 has ONE RED wire going to the suction cup. It is unfortunate that Zenith chose to partly redesign the circuit board from Wells-Gardner's design in order to use a proprietary Zenith made flyback. This particular flyback (Zenith numbers 95-4149 and A-15945) is no longer available anywhere thus making this chassis unrepairable should the flyback fail (a common problem). The flyback for standard Wells made k7000 (the 0528 flyback available from many suppliers) will not physically nor electrically work to repair the Zenith made chassis.

So if you have a k7000A chassis and the flyback is bad, then you're only hope to repair the monitor would be to either get a working regular k7000 Wells-made chassis (direct plug 'n play swap) or order an 8liners.com universal replacement chassis.

BTW, the k7000A uses the same cap kits as the regular Wells-Gardner K7000 monitors. Zenith kept the same component designations (and values) on the pc boards at least.

Oh, and to further confuse people, Wells used (mostly) Zenith picture tubes in both versions.

[hatrick]

Kevin,
I'm hoping to have some time this weekend to snap some pictures and gather some info off my Zenith K7000a so we can continue our discussion.

Thanks for all of the info you have provided so far. Very useful stuff. I'm interested to see a picture of how the caps in the "C36" area under the board are arranged. 

Attached is a really crummy cell phone pic of the "C36" area and the weird combination of caps on my K7000a.

Do you happen to have the values on the caps on yours?

Thanks again.
Dan

[Kevin Mullins]

You would ask right after I put them back in the box. 
(j/k)

I'll pull them out and take a pic or two and see what those values are.....probably will be later this afternoon though.

[hatrick]

You would ask right after I put them back in the box. 
(j/k)

hehehe...sorry about that. I intended to get back to this sooner, but when I'm working at a paper mill, I don't always have reliable internet access, then I got home and had to do non fun stuff instead of playing with my toys in the garage. I hate when real life gets in the way of my play time!
No rush, I'm at work now and will be out again for a day or so. I really appreciate the info you've provided so far. It seems there are very few of these K7000a's around to gather info from. WG said they don't even have any info on them anymore since they don't support them. I bet they have a file tucked away somewhere that has the schematics, but just don't want to share.

[Kevin Mullins]

Well, would be our luck the labeling side of the capacitor on all of them were facing down, so after being tossed around and stack for who knows how long and where acouple of the numbers were a bit hard to read.
But I deciphered them the best I could as two of them were identical and the other one had slightly different values. And the identical ones looked like they hadn't ever been touched before, the other seemed to have issues in that area.

Large - 862J 1.6Kv
Small - 102G 1.6Kv

The one that was different had -
Large - 992G 1.6Kv
Small - 561J 1.6Kv

Compare those to yours and see what you have, I might have one or two numbers off due to the scratching of the labels.

EDIT:
Added the second pic because I noticed yours was positioned slightly different, but in fact those two points are indeed connected with a trace.

[hatrick]

First of all, WOW, those are clean! Mine looks like it was onboard the Titanic when it went down.

So my cap values are:

Big Cap:       862G 1.6kv
Small Cap:   102G  1.6kv

So that is .0086 uf and .001 uf  = .0096 uf total.

That's the same as one of yours, which makes me feel better. I thought for sure it was a post factory hack job.

The values on the other monitor you have seem quite a bit different, but I don't know enough about these to know if that would make much of a difference. I DO know that when I removed my two caps and replaced them with a .0036 from a normal K7000, that it made the picture width shrink significantly.

Thanks again for checking into these. I'll put these two caps back on mine since they seem to be from the factory.

It would be nice to compile all the information on the differences of the Zenith K7000 and put it on the web somewhere. There really isn't much info out there beyond what Ken Layton has shared about the origin of the K7000a.

[Kevin Mullins]

First of all, WOW, those are clean! Mine looks like it was onboard the Titanic when it went down.

Dishwasher ..... 
And they weren't really in that terrible of shape to begin with.

So my cap values are:
Big Cap:       862G 1.6kv
Small Cap:   102G  1.6kv

So that is .0086 uf and .001 uf  = .0096 uf total.

That's the same as one of yours, which makes me feel better. I thought for sure it was a post factory hack job.

Well, yours are the same as TWO of mine...... so we can definitely go with those as "factory".
The other one of mine...... no idea what the story is behind it.

And I haven't taken the time to trace the board out to see what those caps are inline with and what they may do or anything like that.

It would be nice to compile all the information on the differences of the Zenith K7000 and put it on the web somewhere.

So you planning on drawing up the schematics or what?   
Someones bound to have a set..... somewhere.
I actually like digging up information on oddball stuff like this anyways.