1982 Millipede Replacing Matsushita TM-202g with Wells Gardner 4900

[sudonate91]

I have dived into helping my father in law restore a bunch of arcade machines. One machine being a 1982 Millipede. It had a bad Matsushita TM-202g. I originally went the route of replacing the flyback (the originally was trying to light itself on fire). Once i replaced that the sparks just transferred to behind the tube. I was going to go forward to recapping it but then I found this forums. Seems to be consensus that he TM202g is junk and it should be replaced. So I bought a Wells Gardner 4900 (found here on ebay) that has been recapped and working off ebay. I got to put it together and most of the conversion seems to make sense. The data cable fits, the ground cable needs some modification, any some other cables seem 1:1 given I break apart the original adapters. So I go and try to put the board on the back of the tube. This is where I am left scratching my head. The prongs dont seem to line up, and need to be twisted slightly to allow it to slide in. Even after the bending - it doesn't go in all the way. Attached is the picture of how I need to bend the pins.

Any advice on how to go forward?


Thanks,

Nate

 

[Talsivar]

Are you trying to force the k4900 chassis to work with the matsushita tube? Because that's not gonna work.

 

[cwilkson]

Are you trying to force the k4900 chassis to work with the matsushita tube? Because that's not gonna work.

Oof! Yeah, @Talsivar is right. The pinout is different. The pin spacing is different and the functional pin order is different. I hope you didn't ruin your CRT by bending those pins. I don't know how robust the neck glass and pin/glass vacuum seals are on the 51TFB22 tube. Try to put the original Matsushita connector back on and hope it still fits smoothly. If it doesn't, you'll have to straighten the pins. Be gentle and move slow! You don't want to fatigue the metal pins or the vacuum seals.

Now for your original problem....

You need to use a 19VLTP22 (or equivalent...there are many types) tube with the WG4900 chassis. Or you need to use the Matsushita chassis with your tube.

You could try to make an adapter, but I have no idea if the 2 different tube types are electrically compatible. They are definitely not mechanically compatible as you learned yourself. Whatever you do, don't start cutting wires on either of your monitors chassis!

KLOV is a great resource and you should stop here first for technical help. You could probably get some help locally too. Where in Missouri are you located? There's a pretty big collector community in KC. (I'm sure St. Louis is the same.) Used to be a guy in Higginsville, but he's in Detroit now.

 

[mecha]

K4900 is particular about yokes too. in fact, they were produced with 2 different ones, and a mismatched chassis/yoke pairing, even though it's a K4900 yoke, will not work right.

you'll be better off sourcing a whole other monitor from someone nearby.

 

[DZA]

Ouch.

Rule number 1 - don't force anything.
Rule number 2 - when in doubt ask.

You got rule number 2 right.

You say you are restoring a "bunch" of machines. In that case, save the 4900 for another game that has the right tube already. Likely easier than finding a tube unless you can find some connections.

As for your Matsushita chassis, someone here should be able to fix it.

This is a new site that is making the rounds
https://d2gc2ab6wanhq2.cloudfront.net/ - you can use this to look up tube information. Questions welcome.

 

[Scott C]

Oof! Yeah, @Talsivar is right. The pinout is different. The pin spacing is different and the functional pin order is different. I hope you didn't ruin your CRT by bending those pins. I don't know how robust the neck glass and pin/glass vacuum seals are on the 51TFB22 tube. Try to put the original Matsushita connector back on and hope it still fits smoothly. If it doesn't, you'll have to straighten the pins. Be gentle and move slow! You don't want to fatigue the metal pins or the vacuum seals.

Now for your original problem....

You need to use a 19VLTP22 (or equivalent...there are many types) tube with the WG4900 chassis. Or you need to use the Matsushita chassis with your tube.

You could try to make an adapter, but I have no idea if the 2 different tube types are electrically compatible. They are definitely not mechanically compatible as you learned yourself. Whatever you do, don't start cutting wires on either of your monitors chassis!

KLOV is a great resource and you should stop here first for technical help. You could probably get some help locally too. Where in Missouri are you located? There's a pretty big collector community in KC. (I'm sure St. Louis is the same.) Used to be a guy in Higginsville, but he's in Detroit now.

Totally Agree. You need to hold off doing anything else until you have a clear path forward, so you don't damage something.

Where are you in Missouri? I'm may be able to assist depending upon your location.

Based upon the ebay listing, you have a 4-pot chassis, so you'll likely need the latter (higher number) yoke.

Scott C.

 

[sudonate91]

Holy cow somehow I missed all these responses. So some context - here is a reddit post that started my endevour

https://www.reddit.com/r/arcade/comments/quuyub

...


The machines I have are
1982 Millipede

1979 Galaxian

1989 Black Knight 2000 Pinball Machine by Williams

1988 DataEast Secret Service Pinball machine

1970 Bowling Machine WorthPoint Williams United Cimarron Shuffle Alley Bowling Machine

Black Night 2000 seems to be mostly working. Main speaker seems to be broke but that's it."

So yeah for some reason i was under the impression I didn't need to replace the tube. So now its either I fork up the 175 I had my father in law spend on this or find a tube to work with it. Any good way to find a tube replacement?



@Scott C I am In O'Fallon MO on the 70 side!

 

[DZA]

So it seems that the only other game is a Galaxian. What monitor is in it? If you don't know, just post a pic.

 

[sudonate91]

So it seems that the only other game is a Galaxian. What monitor is in it? If you don't know, just post a pic.

Yeah they are at my FIL's place right now. Im fairly confident its not compatible. I did get the ebay seller to agree to return the Wells Gardner 4900 at the cost of shipping which seems like a good deal. The next step is figuring out where I go from here.

 

[cwilkson]

Yeah they are at my FIL's place right now. Im fairly confident its not compatible. I did get the ebay seller to agree to return the Wells Gardner 4900 at the cost of shipping which seems like a good deal. The next step is figuring out where I go from here.

O'Fallon is waaaayyyy over there. Maybe the KC guys like Scott can help. But you should try finding peeps in St. Louis area too.




Meanwhile....

Yes. Send a picture of the Galaxian monitor. There are *many* compatible tubes for the WG4900. You can find a list on the Tubular site that @DZA posted. Here's a link to the 19VLTP22 page. Might be a moot point if you've returned the WG4900 chassis.

What is the current status of the Matsushita monitor? What have you done with it so far?

 

[sudonate91]

O'Fallon is waaaayyyy over there. Maybe the KC guys like Scott can help. But you should try finding peeps in St. Louis area too.




Meanwhile....

Yes. Send a picture of the Galaxian monitor. There are *many* compatible tubes for the WG4900. You can find a list on the Tubular site that @DZA posted. Here's a link to the 19VLTP22 page. Might be a moot point if you've returned the WG4900 chassis.

What is the current status of the Matsushita monitor? What have you done with it so far?

So I havnt been able to really check the state of the monitor given the bad chassis. After I replaced the flyback we did get a lit up screen but then the board right behind the tube decided to try to light itself on fire. Here is the orginal board - post flyback replacement https://photos.app.goo.gl/emCwdrCgUPyJjWhg6. I have a cap kit for the Matsushita TM-202g] but I figured it was a lost cause.

 

[cwilkson]

Ooh. Smoke is never good. Flames are worse. Was the fire on the PCB, or inside the tube, or both?

Unfortunately, I've never worked on the Matsushita. I don't know much about troubleshooting it.

Wow...I looked online. Lots of hate for that one.

Suggested first step:
Find someone local with a tube tester and verify that the CRT is good. Don't rejuvenate it, don't even "clean & balance" it, just MEASURE it's emission for now.

 

[sudonate91]

Ooh. Smoke is never good. Flames are worse. Was the fire on the PCB, or inside the tube, or both?

Unfortunately, I've never worked on the Matsushita. I don't know much about troubleshooting it.

Wow...I looked online. Lots of hate for that one.

Suggested first step:
Find someone local with a tube tester and verify that the CRT is good. Don't rejuvenate it, don't even "clean & balance" it, just MEASURE it's emission for now.

The fire/sparks is for sure on the pcb. Before it was on the flyback which is why I replaced it. But once i did - those flames are coming from the connector to the tube. The white fitting part. Yeah the hate for this chassis is why I replaced it. Especially on this forum! I think i can count 2-3 threads that just say its junk and replace. Which I thought it was 1:1 replacement with some tweaks. The pins even look similar but are every so slightly off. This is definitely a learning situation or me! I love learning this stuff - but dang am I a greenhorn.

 

[cwilkson]

The fire/sparks is for sure on the pcb. Before it was on the flyback which is why I replaced it. But once i did - those flames are coming from the connector to the tube. The white fitting part. Yeah the hate for this chassis is why I replaced it. Especially on this forum! I think i can count 2-3 threads that just say its junk and replace. Which I thought it was 1:1 replacement with some tweaks. The pins even look similar but are every so slightly off. This is definitely a learning situation or me! I love learning this stuff - but dang am I a greenhorn.

Heh. My first monitor repair was the TV from a Computer Space. It was a vacuum tube based chassis. I think it had 7 tubes plus the CRT. It was old and cheap (just a super cheap GE portable TV) so everything was brittle and I was terrified of making things worse. Especially because it was so rare. But I kept at it, learning as I went. Eventually I got it all working and took it to California Extreme in 2008 or 2009. It ran like a champ the whole weekend.

Stick with it! And good luck!

 

[geech]

Ouch.

"unplug, UNPLUG"

 

[mcdermd]

You need to use a 19VLTP22 (or equivalent...there are many types) tube with the WG4900 chassis.

AND the correct yoke ... which he doesn't have.

 

[cwilkson]

@sudonate91 if you can't get the Matsushita rebuilt and working, and you choose to go down the replacement path, be sure to check in here before you buy stuff.

AND the correct yoke ... which he doesn't have.

Yes. Thank you!
The tube, the yoke, and the chassis all have to match. And they need to fit the frame and the frame and tube have to fit in the cabinet. It all has to work together.

In my brain, the tube always comes with the correct yoke attached for the chassis I'm trying to complete. Everything is correct by default, because why would I buy it otherwise? But it's 100% NOT true. These things have been broken into pieces, and mixed and matched, and force fitted back together whether it's correct or not, for decades now. And in the case of the 4900, there apparently were 2 different yokes used. I didn't know that until this thread. Never needed to know.

 

[sudonate91]

@sudonate91 if you can't get the Matsushita rebuilt and working, and you choose to go down the replacement path, be sure to check in here before you buy stuff.



Yes. Thank you!
The tube, the yoke, and the chassis all have to match. And they need to fit the frame and the frame and tube have to fit in the cabinet. It all has to work together.

In my brain, the tube always comes with the correct yoke attached for the chassis I'm trying to complete. Everything is correct by default, because why would I buy it otherwise? But it's 100% NOT true. These things have been broken into pieces, and mixed and matched, and force fitted back together whether it's correct or not, for decades now. And in the case of the 4900, there apparently were 2 different yokes used. I didn't know that until this thread. Never needed to know.

Based on my video of the sparks, is the original board even rebuildable? I have no idea what could be causing that. I dont mind doing the rebuild work myself but I have no idea where to get parts.

 

[mcdermd]

Of course it can be repaired.

 

[Scott C]

Based on my video of the sparks, is the original board even rebuildable? I have no idea what could be causing that. I dont mind doing the rebuild work myself but I have no idea where to get parts.

It was needs to be repaired by someone familiar with that monitor, but it definitely can be repaired.

One suggestion: https://arcadecup.com/

Scott C.