Turbografx 16 / PC Engine s-video mod

[Drakon]

Found a major flaw in the circuit. Here's the fixed circuit:

The video signals come from the huc6260 chip











Big thanks to thesteve for coming up with this (atleast I think he's the guy who came up with it)

[Lastcallhall]

A much easier circuit has already been found on pcenginefx.com, in part by my research and testing (but most of the credit goes to TheSteve):

http://www.pcenginefx.com/forums/ind...6287#msg206287

[Drakon]

wtf? I wired an amp on the luma line and it was too strong so I straight wired it and it's perfect. My mod all you do is remove 1 resistor and wire it up. How is yours simpler exactly? Maybe yours needs an amp because your luma is still connected to the rest of the circuit?

Also out of curiosity, what model did you do your mod to?

I'm also looking for an amp circuit for the tapped left and right audio connections. Audio is too quiet just straight tapping them.

[Lastcallhall]

Desoldering on that board is just asking for trouble. Plus the solder joints on the EXP out are packed really close together - there's a chance for bridging if you're not careful. The PC engine board's quality is just poor to say the least. But hey, if you're cool with that, go for it. I'm all about alternative methods for mods.

I used a Turbografx 16 for the initial mod, and my own Duo-R for an additional test.

[Drakon]

Desoldering on that board is just asking for trouble. Plus the solder joints on the EXP out are packed really close together - there's a chance for bridging if you're not careful. The PC engine board's quality is just poor to say the least. But hey, if you're cool with that, go for it. I'm all about alternative methods for mods.

I used a Turbografx 16 for the initial mod, and my own Duo-R for an additional test.

Uhh I found the pc engine pcb to be quite rugged. Removing the surface mount resistor just required heating up both sides of the resistor at once with a soldering iron. The pins on the expansion port are pretty far apart to me. I really have no idea why disconnecting luma from the circuit turned the composite video pin into a perfect source for chroma....oh well it works great so smeh.

[Lastcallhall]

It could be different across countries - my Duo-R board is pretty solid.

[Drakon]

It could be different across countries - my Duo-R board is pretty solid.

I worked on the cheapest of the cheap. The original white japanese pc engine. And it doesn't feel fragile at all to me, just uses small parts.

[Lastcallhall]

I don't know - when I've desoldered the RF shields from the TG itself, bits of the board come off with it. It's inevitable. But we're splitting hairs here.

[Guntz]

Lastcallhall was originally talking about the TG16 PCB being poor quality. To me, the biggest offense on the TG16 PCB is the RF shielding is soldered in place. Talk about cheapest of the cheap.

[Drakon]

I didn't even desolder the shielding I just...pulled it off carefully. I desoldered the small pieces that were still attached afterwards. I didn't have any pcb bits come off.

That RF box was the most annoying thing to get out, everything else was a cakewalk. I've never even seen a tg16 I had no idea they're fragile. Then again I'd never seen a pc engine either until it showed up in the mail today.

[ELabit]

A much easier circuit has already been found on pcenginefx.com, in part by my research and testing (but most of the credit goes to TheSteve):

http://www.pcenginefx.com/forums/ind...6287#msg206287

I must say, thesteve is a real pro and has been doing mods and services for the pce crew that nobody has mastered till he came along.

[Drakon]

Well I'm glad I'm not the first to do this. The mod seemed way too simple to figure out for me to be the first guy to come along and work it out. That video circuit diagram I built my schematic on made the mod super easy to figure out.

My circuit is pretty darn easy the only parts you need are wires and a s-video jack.

[goombakid]

I did the same S-Video mod from PCEngineFX.com since that was the easiest one that I've seen prior to this. Works fine for me.

I'm in with Drakon about an audio amp. I've added 10 uF caps to the audio lines but still get quiet audio. Anyone have ideas?

[Ace]

Looking at that, has anyone managed to get straight Component video working off of the PC Engine? If not, I may try something on my region-switched TurboGrafx 16.

[GohanX]

I play in component by converting the RGB.