Nintendo Sanyo tube swap

[MaximRecoil]

I knew that there was an old 19" TV out in the shed that didn't work, it has been there for a few years. It is an early to mid-80's TV with the same light grey screen (as opposed to the dark grey screens that started showing up in the late 80's) as my arcade monitors. It used to belong to my sister and was out in her garage for a long time before I grabbed it. A few years ago I rescued it because I had read a thread here about "8-Liner's chassis" where you could match up an arcade type chassis to a regular TV tube and have an instant arcade monitor. So, I figured I'd hold onto it for a future project maybe.

So, I just read that people have swapped Zenith tubes onto Nintendo Sanyo's and that as long as the neck board fits, any same-size TV tube will work. Now, I thought for sure that that old TV out there was some off brand or something because all I remembered was some cheesy sounding name like "Spectra 2000" on it...It is a *Sanyo*. A Sanyo Spectra 2000 to be precise, lol.

Now, from what I have heard, usually, even when these old TV's don't work for one reason or another, their tubes are still good. Hopefully this is the case here. What this TV is doing is, when you turn it on, you see static (it isn't connected to a signal of any sort) for a second or two and then it fades to nothing. It does this each and every time you turn it on, the picture just won't stay on the screen for more than a second or two. So, I have no idea what is wrong with it, but do you all think the tube would be good to swap the Nintendo/Sanyo chassis onto?

I took the back off the Sanyo Spectra 2000 TV and everything looks the same. There is even a sticker on the inside of the casing that has a diagram of the neck board and the flyback transformer. At the top of the sticker it shows that it applies to CRT models: 19VMFP22 / 19VLTP22 / 510UTB22. The tube in that TV is a 19VMFP22. The CRT's in my arcade machine are both 510UTB22's according to the stickers on the neck guard cages. This looks like it would be a direct swap maybe? it even looks like I could use the flyback transformer off that TV if I need it and it is any good?

[Ken Layton]

The yoke on the tube must have a closely matched impedance also in order to work properly. The vertical section of the yoke if it measures 9 to 16 ohms is considered a low impedence and 30 to 60 ohms is considered high impedance. The Nintendo Sanyo monitor is a high impedance.

Check out:
http://chux0r.org/20EZ.php

[MaximRecoil]

The yoke on the tube must have a closely matched impedance also in order to work properly.

Isn't that only if you keep the yoke from the replacement tube? I was under the impression that a bare tube was pretty much universal as long as it is the same size and has the same socket for the neck board.

Anyway, since this is a Sanyo TV of a similar vintage as my Sanyo arcade monitors, and it even has a sticker inside it which has the same CRT number as my arcade monitors, I'm hoping things will match up pretty good.

The guy in this thread kept the purity/convergence rings from the TV and swapped over the yoke. Is that the recommended way of doing it?

I don't suppose there is any place to find detailed specifications on the Sanyo Spectra 2000 TV is there? I would like to know if the flyback transformer is the same as the one on my arcade monitor. They look the same, and have the same leg pattern to solder them to the chassis.

Assuming everything is the same/compatible, what would be the simplest way to approach this? Could I keep the yoke and covergence rings from the Sprectra 2000's tube?

[MaximRecoil]

The tube swap was a success (I reused the yoke from the arcade monitor and kept the purity rings from the TV tube), but now the convergence is off and the picture is rotated a little to the right. I guess you can fix the rotation issue by turning the yoke, right? Is it safe to turn the yoke while the monitor is on? I'm guessing the convergence is adjusted by tilting the yoke and/or turning the purity/convergence rings?

The picture doesn't seem to have the green haze over it anymore, though the retrace lines are still there and it still snaps when it warms up, so I guess the snapping is somewhere else. The screen that used to have the green background like I took a picture of now has a grey background, it seems like the contrast needs to be adjusted to get it to black but I can't find any contrast adjustments on the thing. The brightness pot is already turned all the way down.

[Ken Layton]

There's also a "sub-brite" control on the main monitor board as well as the screen control on the flyback. Sounds like the screen control is already set a tad bit too high. Try turning it down a bit to remove the retrace lines.

You can rotate the yoke to straighten up the picture. Wear leather gloves while doing this as the monitor will need to be on. Your hands may pass next to the red high voltage wire (containing 24,000 volts!) while the monitor is operating. The leather gloves are for your safety!

[MaximRecoil]

Well, I turned down the G2/screen pot on the flyback transformer and then adjusted the brightness pot and it is now perfect, as good as the top monitor. The only problem is, it is still arcing when it warms up.

BTW, I swapped it back to the original tube since that didn't fix the arcing (someone thought it could be a CRT short) and after I got the yoke adjusted, it looked the same as the original tube anyway. I learned how to swap tubes in the process and now have a spare tube that I know is compatible if I ever need it.

[Ken Layton]

I just fixed a regular Sanyo 20EZ last week with an arcing flyback. If you take the chassis out and put it under a strong light, clean the flyback off well, look closely and you'll see some fine cracks in the case (usually on top). The arcing occurs from the fine cracks since 24,000 volts will easily find it's way out through those cracks. I use a glob of clear silicone glue to patch it since it's an excellent high voltage insulator once it cures in 24 hours.

[MaximRecoil]

I just fixed a regular Sanyo 20EZ last week with an arcing flyback. If you take the chassis out and put it under a strong light, clean the flyback off well, look closely and you'll see some fine cracks in the case (usually on top). The arcing occurs from the fine cracks since 24,000 volts will easily find it's way out through those cracks. I use a glob of clear silicone glue to patch it since it's an excellent high voltage insulator once it cures in 24 hours.

Yup, I have read about this and it sounds like a great idea. So just regular clear silicone adhesive like you buy at the hardware store? The stuff that stinks to high Heaven? Just to be thorough, I could probably coat the whole thing couldn't I?

Edit: I've got some "GE Silicone II 100% Silicone Sealant Clear" right here at the house. Will that do the trick? I also have some "Car Quest Clear Adhesive Silicone", but not as much left in the tube.

Edit 2: Okay, I have the flyback cage off and I swabbed the top of the flyback transformer down with alcohol and with a bright light, you can see the cracks plain as day, it is a star shaped crack, i.e. a series of about 5 little cracks radiating in a roughly star-shaped pattern out from a central point. I'm going to put some silicone on it and...do I really need to wait 24 hours?

Edit 3: Healthy dose of the CarQuest silicone adhesive applied and the house smells wonderful. Now to wait 24 hours :|

I have a few other minor problems with both monitors. The bottom one that I have been messing with all along (the one with the arcing) has a very slight color purity problem on the reds (pure reds fade to a slightly lighter shade of red toward the center of the screen). I'd imagine that one of the purity rings has to be moved ever so slightly because after the tube swap,and then the swap back to the original tube, even though I marked the purity rings with a marker, they may not have ended up in the *exact* position as before. The yoke is in the right position because the convergence is perfect and the picture is square. The rubber wedges were still stuck to the tube so I just pressed the yoke down level against all three of those and tightened the metal retaining band. Is there a specific ring to adjust for red purity?

The top monitor's reds are all very dark, how do I get those back to normal?

BTW, about the Sanyo 20-Z2AW's in Punch-Out machines having degauss switches, I came across this:

Newsgroups: rec.games.video.arcade.collecting, rec.games.video.arcade.marketplace
From: anth...@quarterarcade.com - Find messages by this author

[Ken Layton]

Always manually degauss the picture tube before doing any purity setups.

Overall color purity (especially red and green) is controlled by how close or far away the yoke is from the "bell" of the picture tube.

[MaximRecoil]

Always manually degauss the picture tube before doing any purity setups.

Overall color purity (especially red and green) is controlled by how close or far away the yoke is from the "bell" of the picture tube.

Okay, so I probably need to slide the yoke back toward me a bit? It is already forward as far as it will go, right up against those rubber wedges.

I tested it out after letting the silicone dry over that obvious star-pattern crack for about an hour and a half and I still got arcing. So this time I pulled the monitor out to get a better look at the flyback transformer, and removed the top metal shield-looking thing and the G2 and focus pots that were screwed to the side of it. Behind the plastic piece that the G2 and focus pots mount to, there were two more very noticeable cracks. I packed that side with silicone and then went to work coating the entire outer surface of the plastic flyback transformer housing with silicone. If this doesn't work, nothing will (other than a new flyback transformer). I am positive now that the arcing was happening at the flyback transformer, because while I was looking in the back while it was arcing, trying to figure out where it was coming from, listening and looking for visual signs of the arc, I saw something move. In one of the vent holes in the flyback cage, there was a tiny dust bunny hanging, and each time I heard the arc, that dust bunny would move.

I'm going to give it another hour to dry, put it back together and see if I got it this time.

[Ken Layton]

Let the silicone glue dry for 24 hours before powering up the monitor. The silicone glue can conduct electricity when still wet/curing.

[MaximRecoil]

Let the silicone glue dry for 24 hours before powering up the monitor. The silicone glue can conduct electricity when still wet/curing.

Before I read your post I powered it up and it is still arcing. I guess I won't know for sure whether it is fixed or not until this time tomorrow.

If this doesn't fix it, is there a way to tell if the flyback transformer in that Sanyo Spectra 2000 TV I have is compatible? The tube was definitely compatible if that means anything. There is probably more to it than it simply being able to fit in the board (same solder leg pattern), huh?

[Ken Layton]

Chances are the tv flyback is not compatible. All Sanyo flybacks are numbered with an "F" and four digits in ink on top of the flyback.

Arcadeshop.com sells the reproduction Nintendo Sanyo flybacks.

[MaximRecoil]

Chances are the tv flyback is not compatible. All Sanyo flybacks are numbered with an "F" and four digits in ink on top of the flyback.

Arcadeshop.com sells the reproduction Nintendo Sanyo flybacks.

Yeah, the one on the TV looks similar but is not identical. It has a different number too. After spending about an hour cleaning and coating that flyback transformer with silicone, I got very familiar with the way it looks and when I looked at the one on the TV again, I noticed several differences right away.

I know that ArcadeShop.com sells a reproduction from Cinelabs, but I want to exhaust all free or cheap options before coughing up $40 + shipping. Maybe when the silicone has cured for 24 hours it will be fixed. I'll keep my fingers crossed.

[MaximRecoil]

It's been over 24 hours and it still arcs. Why can't I see a spark anywhere when it arcs? Is it arcing internally inside the flyback transformer?

These Sanyo's don't have protective "spark gaps" do they?

[Ken Layton]

A flyback can arc underneath itself and it can arc internally. The red high voltage wire to the picture tube could be 'nicked' and can arc from there too. That's a reason I always like to clean that red wire off real nice when I do capkits. It helps me to inspect the wire for nicks where arcing can occur. I have a feeling you need a new flyback.

It is also very possible for the yoke on the picture tube to be arcing internally.

If I remember correctly, Nintendo Sanyo monitors have the spark gap built into the picture tube socket on the neckboard. Nintendo Sharp monitors on the other hand have seperate spark gaps mounted on the neckboard next to the picture tube socket.

[MaximRecoil]

The red high voltage wire to the picture tube could be 'nicked' and can arc from there too. That's a reason I always like to clean that red wire off real nice when I do capkits. It helps me to inspect the wire for nicks where arcing can occur.

You would be able to see an arc from the HV wire in total darkness wouldn't you?

I have a feeling you need a new flyback.

I do too. There may be a problem with that though, even if I wanted to shell out the $40 + shipping. According to the Cinelabs site:

This Flyback is designed to replace the Sanyo F5024 (99-160669).

http://www.cinelabs.com/flybacks.html

The flybacks on my monitors are Sanyo F5039's. I can see from their closeup pictures there that the screen and focus pots are mounted differently than on mine as well, theirs having two screws mounting it to that metal bracket near the flyback, and mine have one screw and one plastic stud and mount directly to the side of the flyback, not to that metal bracket.

Note that this reproduction flyback is intended for the "Sanyo EZ20". EZ20, 20EZ, EZV, 20EZV (R-B,V)...what are these things actually called anyway? and why do they have forty-eleven different names for seemingly the same monitor? Anyway, like I was saying, that flyback is meant for the Sanyo EZ20 (or whatever), the infamous Donkey Kong/Mario Bros/Popeye degauss-switchless monitor that I don't have. Mine are Sanyo 20-Z2AW's with factory installed degauss switches and apparently, different flybacks (though they take the same cap kits as the EZwhatever).

It is also very possible for the yoke on the picture tube to be arcing internally.

I suppose the only way to fix that would be with a replacement yoke? It really seems to be coming from the flyback area though.

If I remember correctly, Nintendo Sanyo monitors have the spark gap built into the picture tube socket on the neckboard. Nintendo Sharp monitors on the other hand have seperate spark gaps mounted on the neckboard next to the picture tube socket.

In the socket? You mean within the white plastic socket housing itself, where you can't see it or get at it?

[Ken Layton]

You should be able to see the hv arcing if it were coming from the red wire in the darkness. Always be careful with the routing of that red wire to keep it away from the metal frame. That's why Sanyo put those white plastic standoffs on the frame to dress the high voltage wire away from the metal by at least one inch.

I was unaware of any other part number on Nintendo Sanyo flybacks other than F5024. You should email cinelabs and arcadeshop.com for some clarification.

Collectively these monitors are simply known as "Nintendo Sanyo 20-EZ" regardless of variations.

If the yoke were arcing there's no way to fix that except for a new yoke.

Many television sets and arcade game monitors do have the spark gaps located inside the picture tube socket. Some sockets are sealed so you can't get into them. If it's suspected there's an internal problem with one of those sockets then you simply replace it with a new socket
(cost is around $8 or so).

[MaximRecoil]

E-mail response from ArcadeShop:

I can't say if it will work or not.