Thinking of recapping my neo-geo cab

[g00ber]

I've got a neo-geo 2 slot arcade monitor, that looks fuzzy (not very sharp). I'm thinking I need to recap the thing, but i'm clueless as to what I need to know. I've tried every adjustment to the colors and hues to make it look as good as possible, but its like playing a game through smudged glasses.

Some questions i have:

1) How do I tell what kind of monitor I have?
2) Where can I get a cap kit from?
3) Is my problem likely related to the capacitors?


I'm aware of the dangers of these monitors, so i'll be very careful in working with it. I'm also fairly good with a soldering iron, so i'm pretty confident I can do this myself.

If someone has done something similar with a neo geo cab, i'd love to hear about the steps you took to recap your unit.

Thanks.

[Arcade Antics]

Did you try to adjust the focus knob? Is the screen filthy?

1) post pictures.
2) you can order a cap kit from lots of places, but the big two are Bob Roberts or Zanen Electronics.

[nhm]

I would register at Neo-Geo.com and post this question on their boards. You will probably get better answers there.

[aclbandit]

If you order the cap kit from Bob Roberts, it'll include instructions about which caps go where. All you need to do is DISCHARGE IT (so that you don't die), take out all the plugs/screws, replace all the caps as per the included instructions, and hook it all back together.

EDIT: Also, when ordering the cap kit, know which model your monitor is. The caps you'll be replacing are on the chassis, NOT the tube. The "chassis" is the circuit board in the back. You'll find the model number Bob will need on that chassis.

[diskoboy]

It could never hurt..

Monitors always look factory fresh after a proper cap job. And it means you won't have to worry about most major problems again for a long while.

Post a pic of the monitor, if you can. We can probably figure it out by looking at it.

I believe most Neo cabs have WG monitors, I believe. And if it's a K4600, be prepared to get extremely frustrated. Whoever designed them didn't take repairs into consideration. It is the most poorly designed, and most frustrating monitor I've ever worked on - The width coil is attached to the chassis, not the PCB. Fixing a busted coil is next to impossible.

If it's got 2 small boards connected to the monitors main board, it's a 4600. If it's an Electrohome G07, consider yourself lucky. G07's are a breeze to rebuild/cap. If you need a cap kit for a G07, I can hook you up - I have a ton of Xicon caps left over from the 3 monitors I recapped last fall.

[Arcade Antics]

I would register at Neo-Geo.com and post this question on their boards. You will probably get better answers there.
Super helpful. :roll:

Without knowing if he's even tried to adjust the focus pot, there's no need to recap it yet. All he mentioned was adjusting the color pots, which has zero to do with focus.

If the screen is filthy, it could also contribute to the issues the OP mentioned.

Fastest way to figure out what monitor is in there is to post pictures. We don't know if it's a dedicated Neo cab or what it might have been converted from.

[g00ber]

Thanks for all the replies.

I managed to capture a label that says Model 25K7191.

I did a google search and it looks like its a Wells-Gardner model.

I've cleaned the entire front of the screen - its definately not a dust issue.

Perhaps someone can point out the focus pot? (images are listed below)

[g00ber]

Here are some pics:

http://img132.imageshack.us/img132/5176/p1070723l.th.jpg (http://img132.imageshack.us/i/p1070723l.jpg/)

http://img512.imageshack.us/img512/8201/p1070722.th.jpg (http://img512.imageshack.us/i/p1070722.jpg/)

[Arcade Antics]

Second picture you posted, left side of the chassis, black thing with two pots is the flyback. Top one is focus, it's usually labelled, other one should be screen. Slight adjustment should get you back up and running. :)

[g00ber]

I went to Bob Roberts site, but he doesn't have the exact model listed.

K7000 13"/19"/25" color
K7200/1 Color - Not For K7203
K7203 Color
K7302 Color
K7400/K7500 High Temp Cap Kit

Which one is it?

[g00ber]

Second picture you posted, left side of the chassis, black thing with two pots is the flyback. Top one is focus, it's usually labelled, other one should be screen. Slight adjustment should get you back up and running. :)

Adjusted the focus.. its better, but I still think it may see more improvement with a cap kit.

Ah, just check the bob roberts site again, and the K71xx gets the K7000 kit. I'm gonna try and get that i think.

I'll let you guys know if I see a difference (before and after pics)

[XYXZYZ]

I had a WG K7000 with a similar problem, turns out the flyback unit was shot. (the focus control didn't work) and I learned that K7000 flybacks were notorious for failure, even an aftermarket replacement is better than the original part. After changing it the image was nice and sharp. Given it's failure rate, it wouldn't hurt to replace the flyback when you do the cap kit. As long as you're soldering stuff on the chassis, you know.

Here's one for $36.00 shipped (http://cgi.ebay.com/WELLS-GARDNER-K7000-SERIES-FLYBACK-TRANSFORMER_W0QQitemZ360236202413QQcmdZViewItemQQp tZLH_DefaultDomain_0?hash=item53dfc039ad)

[g00ber]

I had a WG K7000 with a similar problem, turns out the flyback unit was shot. (the focus control didn't work) and I learned that K7000 flybacks were notorious for failure, even an aftermarket replacement is better than the original part. After changing it the image was nice and sharp. Given it's failure rate, it wouldn't hurt to replace the flyback when you do the cap kit. As long as you're soldering stuff on the chassis, you know.

Here's one for $36.00 shipped (http://cgi.ebay.com/WELLS-GARDNER-K7000-SERIES-FLYBACK-TRANSFORMER_W0QQitemZ360236202413QQcmdZViewItemQQp tZLH_DefaultDomain_0?hash=item53dfc039ad)

Thanks for the link. I did play around with the focus, and it did appear to be working. Not sure whether its the kind of thing that just works or doesn't, or if it slowly degrades over time.

I'll try one thing at a time, and give the cap kit a go first.

--------

Next question: I noticed that the color dials on the back of the tube have two settings for each color. A gain, and a cutoff. What is the difference between the two?

I seem to notice more effect on the picture when I adjust the gain.

[Arcade Antics]

Thanks for the link. I did play around with the focus, and it did appear to be working. Not sure whether its the kind of thing that just works or doesn't, or if it slowly degrades over time.

I'll try one thing at a time, and give the cap kit a go first.
If you're taking it all apart anyway, best to put a new flyback in there at the same time for two reasons:

1) it's easier
2) if you replace the caps and not the flyback there's a very good chance that the flyback will blow, potentially wrecking a lot of the nearby new caps you just installed.

Did you adjust the screen control on the flyback, or just the focus? If you can post a photo of the screen we'll have a better idea of what's going on.

[g00ber]

If you're taking it all apart anyway, best to put a new flyback in there at the same time for two reasons:

1) it's easier
2) if you replace the caps and not the flyback there's a very good chance that the flyback will blow, potentially wrecking a lot of the nearby new caps you just installed.

Did you adjust the screen control on the flyback, or just the focus? If you can post a photo of the screen we'll have a better idea of what's going on.

Hmm.. in the picture, and when i looked at the other knob underneath the focus it had some hot glue on it to keep it from being adjusted. Is it safe to adjust the screen control as well?

Also, why would the flyback blow?

[Arcade Antics]

Hmm.. in the picture, and when i looked at the other knob underneath the focus it had some hot glue on it to keep it from being adjusted. Is it safe to adjust the screen control as well?
It's safe to turn. They add the glue at the factory once it's all set up, but over time you may need to readjust it.


Also, why would the flyback blow?
Because it's 20+ years old. It probably won't explode (it's not a G07 :) ), but it's likely to fail sooner or later if it's the original. If you're going to recap it anyway, might as well put a new fly in there to save time and headaches.

[g00ber]

It's safe to turn. They add the glue at the factory once it's all set up, but over time you may need to readjust it.


Because it's 20+ years old. It probably won't explode (it's not a G07 :) ), but it's likely to fail sooner or later if it's the original. If you're going to recap it anyway, might as well put a new fly in there to save time and headaches.

Good point.. i'll look into that.

My other question was what is the difference between the color 'drive' and 'cutoff' dials? Gain i've kind of figured out that it increases the amount of one color in the display. I get some bleeding if I apply too much of that. Not sure what the cutoff dial does for Red, Green, and Blue does though.

[TheDomesticInstitution]

I'm a little late here but...

I agree with the others here about the flyback. I put in new caps on a monitor I had, and with just an hour or two of playing my flyback died. I was able to catch it immediately, and turned it off saving further damage. You can do a little research, but some monitors are more susceptible to flyback failure than others. Electrohome G07s are terrible about this.

As far as the color pots go, I've just fooled around with mine a bit, and got the color looking like it should. I don't think there's any special trick to them. If your color looks acceptable then leave them be. Of course if you can get the colors right, that could also point to bad caps.

[itobandito]

Another issue can be the tube is dying. I had a monitor with a new flyback, and capkit and it still wasn't sharp. My buddy ending up having to rejuvinate the tube. This can also kill the monitor if done inmproperly. Rejuvinating also isn't a 100% fix as occasionally the tube can revert to the way it was prior. Haven't had that happen to me yet but I hear it can happen.