Flyback replacement on a historical arcade machine.

Any numbers at all on the flyback?

yes:

TF-1 Tj' 21 TOTOKU

TF-1 Tj' 21 (This could be TJt 21) TOTOKU

Your best bet might be Henri at Asti Magnetics, but they have been bought out by PRB. I do not know what state they are in. (not geographically I mean condition sorta, oh wait, I also did forget what state they're in)

If they got old stock I am sure they will sell it.

Is it purely for the raster, or LV supplies also. 1970s presumably just the former, so half a chance of near enough any LOPT of that time would do with a bit of jiggery-pokery. I've never looked inside a LOPT, are they epoxy filled of that era or still tar filled of the 60s era? Is the bakelite casing likely to contain asbestos fibre reinforcement if you hacked in to the casing, to check out the possibility of a rewind, at least "B&W" only voltages?

I have an extremely old CRT attached to a Space Invaders B&W arcade cabinet. There is no available schematic, that I can find. The flyback has died but there is no modern replacement, mainly because the documentation for the historical model is non existent. So I dont know the input or output voltages, I have no circuit diagram, and I cannot find anything to determine what its input/output parameters can be. I do have the old flyback, I know the monitor size, and I have the actual circuit.

The model is marked as "Toei GM-140 TV MONITOR". It was produced around

My question is this: Can one retro/reverse engineer or somehow determine what modern equivalent could replace a flyback in this circumstance. Is this possible?

YOu may want the game to stay as it is, but if you just want to play the game, you may want to look at some of the converter boards made that will let you use a VGA type of display, either CRT or the newer LED types.

I have Taito B&W monitor schematics that I am trying to scan, they are old blueprints and they have turned VERY blue, so my colour scanner is having a bit of trouble.

Email me and I will send you what I have...

John :-#)#

I would have thought any monitor of that era would have a separate LOPT and tripler module, so is the OP's problem the LOPT or the tripler?

OP: A few photos would help. Speaks a thousand words.

First a visual inspection gives many informations

Seond, try to check the basics (Transistors, power resistors, blown fuses, electrolytic caps and diodes)

Fixing this thing is better than trying a replacement.

Thank you, Have have reached out to them. I'll keep you posted.

inet.. There is no available schematic, that I can find. The flyback has died but there is no modern replacement, mainly because the documentation f or the historical model is non existent. So I dont know the input or outpu t voltages, I have no circuit diagram, and I cannot find anything to determ ine what its input/output parameters can be. I do have the old flyback, I know the monitor size, and I have the actual circuit.

d 1979; or from 1976 onwards.

ne what modern equivalent could replace a flyback in this circumstance. Is this possible?

Hi, I believe it's filled with epoxy. I'll try and post some pict in the n ext few hours. I initially thought about a rewind, but was put off with ho w accurate they had to be. And many appeared to need machines etc. Sounded beyond my capabilities, perhaps. I'm hoping I could find an alternate mode l that works maybe. :)

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I think you've hit the nail on the head, in terms of wanting to keep it as original as possible. I realise that may not be possible eventually, but I so want to try. I have bought a converter ready, and tested it but could not for the life of me get an image to show. Maybe there are other issues too that need attention. But I'll try (against my poor judgement) to focu s on one issue at a time. I am so bad at flitting between several things, it's untrue.

Hi John, if I could look at what you have that might be the answer to my prayers. I can't find your e-mail though. Am I being dense? Is it glaring at me somewhere? Cheers.

I'll post as many photo's as I can later today. Cheers Mike,

I'll post some asap. Thanks.

I'll try and repair all I can, but fear that the Flyback may be beyone my c apability. I'll work on it though, thank you. :)

Does the transformer smoke with the suction cup terminal hooked to the CRT? Did you try to power the circuit with the HV terminal disconnected from the CRT too?

Frank IZ8DWF

I've only tried it with it connected. Should I try it with it out/not-connected? What difference will it make and what should I be looking at when trying this? Cheers.

Shorted CRT, rare but it may happen. You would smoke also the next transformer in that case. If you don't know how to safely disconnect the HV cup (and how to safely test the HV out of the transformer), leave it alone. It can bite you!

Regards Frank IZ8DWF