Need guidance on rehab of SF2CE Arcade Machine (Display=19K7602)

[MeisterKeister]

I inherited a side project.. bringing an SF2CE arcade machine back to life.

Machine was completely dead at start.

Had a local arcade repair guy rehab the boards.. now the game powers on, but nothing from the display.

A closer inspection reveals a cracked neck tube (I believe that's the proper term).

A sticker I found on the chassis reveals the monitor is a 19K7602.

What is my best bet on getting this working within this decade?

1 - Finding just the tube?

2 - Finding a 19K7602?

3 - Finding a 19K7###?


Something else?


Thanks in advance.

[buttersoft]

If the neck of the tube is cracked, that's the end of it, throw it away. Before throwing it away, write down any numbers on the sticker on it, and measure the resistance across the coils of the yoke http://www.jomac.net.au/tech-stuff-2/tech-stuff/ - and count the pins - http://www.jomac.net.au/tech-stuff-2/how-to-check-how-many-pins-your-crt-has/

Write this information down because you'll need it. To replace the tube, you either need one with he exact same number on the sticker, or a donor tube of same or very close size with the same number of pins and shape of socket, and the same readings across the yoke (within ~0.4ohms horizontal and ~2 ohms vertical). You may be able to search for the model number of the monitor/chassis (19K7602) and find replacement tubes, IDK.

This is only going to work if the chassis works, of course. If it doesn't, any arcade monitor of the same size will do the job, remembering that monitor = tube + chassis, and that you may need to change supply voltages to/from 240V depending on what you find or where you are.

[MeisterKeister]

Thanks for the input..

I want to stay as authentic as possible.. a different CRT would be OK... but going LCD or whatever, not interested..

I know the 19K7602 has a sticker which states 60Hz, 85W, 120V.

The tube is a Phillips A48ABK05X

Got 2.3 ohms on the Red/Blue and 13.2 on the Green/Yellow

[buttersoft]

Phillips A48ABK05X - http://tubular.atomized.org/#s/A48ABK05X

48cm tube (US19") with CR-31 socket (looks like the 8-pin picture on the jomac site, right?) which is not as common as the CR-23 socket for that size tube AFAIK. If you wanted CR-23 you could go dumpster diving, but here in Aus only one in mb ten 48cm sets will have the CR-31 pinout.

That said, what you're looking for is any old CRT TV set with 48 or 19 in the model number, or possibly 20 if you're not in the US. So, a Sharp CX-48D3 is good, as is a Teac MV-2010T or CT-M4808H, but not a CT-M5122 or anything with 21 in the number. The tubes you want have rounded corners you could fit a ten cent piece/nickel into comfortably, and if they'e shaper right-angles you're probably looking at a 51cm tube. SOME of these 48cm tubes might have CR-31 8-pin necks, though not any of the ones listed (i'm chasing 48cm CR-23 tubes).

That said, you can often use 51cm tubes, but the chassis *might* require modification. And i have no idea how common the CR-31 neck is on that size tube. And you might have to bore out your cab mountings and cut back the bezel.

You still need the right readings from the yoke, of course. Anything from 2.0 to 2.4ohms horizontal and 14.3 to 14.8ohms vertical is normal. Your vertical coils reading is a little lower than usual, but if you find something closer to that, even better. Otherwise, you can adjust the vertical size down with the chassis pots, i hope? The horizontal MUST be within that specified range though.

If you manage to find a tube online, type it into the tubular site above and see what it says. If it's a TV on CL or something, you can google the service manual and see if it has any information about the tube or its pinout.

All this presupposes the chassis is working and was set up right for the existing tube, which is probable. But if you plug the tube in and see some weird whitish early 80's 3D wireframe landscape, turn the machine off immediately and do not power it up again. 

Remember to be safe around the tubes though, they carry very little charge but at a whopping great voltage that will give you a nasty bite if you don't know how to discharge it safely. Do it every 10 mins or so if you're going to keep handling the tube, as charge bleeds from the glass after they get older and more used.

[MeisterKeister]

Forgot to mention that it is indeed 8 pins...

The meter bounced around a bit between tests... the (horizontal, I assume) bounced between 2.1 and 2.3... while what I guess is the vertical, moved from high 12s to mid 13s.  Coincidentally, I have a new (possibly better, possibly not) multimeter arriving tomorrow... so I should be able to give IT a shot shortly after.. maybe it will yield a more accurate result?

This is starting to sound quite deep though....  I do appreciate the info.

[buttersoft]

On any arcade or TV tube, the vertical is not as important as the horizontal. IDK about PVMs or PC CRTs. As long as you're about 13ohms or above on the vertical coils, you should be able to adjust the size with the pots on the chassis.

For a replacement tube to be compatible with your old one, the horizontal coils (red + (normally) blue wires) MUST read from 2.0 to 2.4 ohms, or possibly slightly higher. Can't remember if i've got one as high as 2.7, but I don't think so. Either way, using a 1.5ohm yoke on a chassis designed for 2.3ohms will soon release the magic smoke from the horizontal deflection components.

It's often hard to get a cheaper meter settled over an inductor, and the values you're bouncing between are inside the ranges above. Which means the replacement tube needs to be as well.