Arcades and TVs

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So I've seen numerous posts on here about swapping tubes from TV with arcade monitors. So if that can be done, why can't just whole TVs (minus the "box" part of it) be put into our games when a monitor goes?
 
Different input connectors. If you have a TV that has connections for RGB and sync then you could do it.
 
They take different input signals, wont work. The good thing is chassis are rebuildable, tubes are not (well, not cost effectively).
 
If you have the knowhow, standard american TV sets CAN be converted to arcade monitors.

Basically all you need to do in pinpoint the 4 spots on the board where RF becomes composite and composite becomes s-video (so you can inject the sync signal there), and then were the s-video gets broken down into the separate RGB or in many cases Component Cr Cb Y signal before it gets amped and sent to the neckboard of the tube.

Just cut the traces prior to that point to not get noise, of course toss on a isolation transformer and inject your video.

Now, do you want to do this? Probably not. Takes a fair amount of digging and get it wrong and you may hurt the chassis, your game board or yourself. Also all of these TVs likely need a good cap kit already and there are no standard kits for them, and there is no documentation readily available.

This project HAS been done before--there was a thread on BYOAC that was censored after someone copying it hurt themselves or something but it had been successful. Myself, I've taken a commodore S-video / Digital RGB monitor (Think 16 level of color IBM PC CGA) and hacked out the Digital->Analog converter and inected analog RGB successfully and got a fully working test bench monitor from it.

You're not going to find a lot of support but it's possible.

However, in the end, it's easier to pick up a replacement chassis for $60 and plug it into the existing tube+yoke (no yoke swap) if you really want a 'fresh' monitor. But given the wide range of yokes, sometimes geometry aren't quite right and many time the replacement chassis have weak power supplies and give hiccups as well.

If you're in Europe or can find some industrial US TV sets with SCART connectors... then it's super easy--the SCART connector has all the pins needed to directly plug in analog CGA and be done.. all from the safety of the outside of the case.
 
Pac-Fan, why would you need to add an isolation transformer?
 
However, in the end, it's easier to pick up a replacement chassis for $60 and plug it into the existing tube+yoke (no yoke swap) if you really want a 'fresh' monitor. But given the wide range of yokes, sometimes geometry aren't quite right and many time the replacement chassis have weak power supplies and give hiccups as well.

Derailing the OP's point for a moment...

You know.. I've been thinking about that after messing with some Happ Visionpro/Kortek chassis. They have a really nice isolated switch-mode power supply with a fully custom transformer. But if that goes out there's not going to be an easy replacement ( unless dezbaz fancies another wound components project :). IMO I think that makes the older chassis more useful with the very simple supply design and a simple ISO transformer.

- James
 
Pac-Fan, why would you need to add an isolation transformer?

Because almost all US TV sets run without isolation. Perhaps some very very recent tube ones had switch mode transformers on them acting as isolation, but almost all of the old ones specifically have large warnings inside about service people to ensure an isolation transformer is used -- when servicing.

Everyone I've popped open are 'hot chassis' meaning one side of the incomming power line is connected directly to the 'ground' of the TV including the tube and seeming harmless heat sinks/etc..

The reason it works and doesn't kill you is because the old ones really only had 2 inputs .. VHF and UHF and they simply put a couple flat brown disc capacitors to prevent the voltage from escaping while allowing the frequencies through from the antenna.

Newer ones often used opto-isolators to protect the inputs. Still newer may have actually gone with real isolation once the cost came down so much on switch mode transformers and the amount of power they pulled dropped considerably in newer designs.
 
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