Monday 16 November 2015

PC Engine Core Grafx PAL RF to RGB

I recently picked up two PC Engine consoles one standard white one and this core grafx. The white one only gives a black screen at the moment so I decided to work on this one instead as it worked. Usually this would be a straight forward case of wiring up a composite cable or rewiring the connector to output RGB, but nothing is ever easy. This Core Grafx had been modded to output PAL RF using an aftermarket pcb and rf box.


What a rats nest.

 Removed the RF box and PCB.

I removed some of the solder mask with a fibreglass pen so I can solder the new connector to the pcb at an angle.

Mega Drive 2 video connector fitted.

Slightly neater than before, I used the through holes in the pcb to feed the wires through.

I should have used a larger connector but since the original was missing I decided to use this one that I had on hand. I also like the idea of being able to use a standard Mega Drive 2 scart lead and not have to make a custom cable.

I installed a THS7314 video amplifier inside the system which I have covered before so won't go over again.

After I tested that it worked as it should I put it back together and then decided to check if C162 should be populated which I should have done before I put it back together, as it turns out it should be. It was so cleanly removed it didn't occur to me that a cap should be there, but a google search told me that C162 is a 470uf 16 capacitor. 

There wasn't room to install it in it's original position so I hot glued it to the pcb where there was space and ran two wires to the two pads.

7 comments:

  1. Hello! Would you be willing to sell or at least make photos from both sides of the PCB with MK5060 chip? I found exact the same one in Famicom and I would like to analyze how it works.

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    1. I just ordered a PAL CoreGrafx from eBay (Canada, of all places). I'll try to get pics but I don't know where I will end up sharing them other than the official Atari Age TurboGrafx-16 thread.

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    2. Here is an image gallery I made about this same board over a year ago:
      https://imgur.com/a/YOrzWiz

      After taking the pics it stopped working and all I got was a white screen until I removed the mod. Removing it restored 60hz NTSC and the CoreGrafx has been working great ever since.

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  2. I don't know if I kept it, if it turns up I'll let you know.

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  3. So, did removing the board revert the system to 60hz?

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  4. Yes and no, it was always running at 60hz but the rf adapter was converting that signal to 50hz to support PAL TVs.

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  5. It was definitely slowing the game down. For example, I played Akumajou Dracula X on it and the CD audio for the intro cinematic finishes way too early. After removing the PAL RF modulator and frequency control mod board it returns to normal (NTSC) and synchronizes perfectly. Mine is exactly the same as yours, found inside a PAL CoreGrafx from a Canadian seller last year.

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