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NEC TG-16/TE/TurboDuo => TG/PCE Repair/Mod Discussion => Topic started by: mamejay on July 26, 2011, 11:15:38 PM

Title: Problem with AV Out PCEngine - strange daughter board
Post by: mamejay on July 26, 2011, 11:15:38 PM

Hello everyone,
i have been doing a few mods on original PC Engines to remove the RF converter and replace it with a din socket to attach a AV cable for RGB and composite output.
I have already completed over 5.
I opened the latest one i got from Japan to find that it has a strange daughter board on it.
From what I can tell this is a crystal oscillator board as I compared it with another PCE I have.
The problem is I get really poor video from the rear composite av connector.  Colour is terrible.
Has anyone seen this before?

Also is it possible to remove this and replace it with a stand alone crystal oscillator?
Does anyone have schematics for the PCE or any notes on the different motherboards used?

Title: Re: Problem with AV Out PCEngine - strange daughter board
Post by: grahf on July 27, 2011, 04:29:55 AM

It sounds like it might be a PAL unit. Strange that you got it from Japan. Any pictures of the daughterboard?

Title: Re: Problem with AV Out PCEngine - strange daughter board
Post by: mamejay on July 27, 2011, 04:16:47 PM

I will get some pics of it posted shortly.  I suspect as much.  I really want to get it back to original.  Looks like its missing a few resistors under the motherboard.

I did not realise that they actuall;y made a white PAL PC Engine.

Title: Re: Problem with AV Out PCEngine - strange daughter board
Post by: mamejay on July 27, 2011, 04:48:57 PM

There must be a way to feed back in a NTSC signal crystal as the solder points are all there.  Does anyone have schematics for the PC Engine?

Title: Re: Problem with AV Out PCEngine - strange daughter board
Post by: Bonknuts on July 31, 2011, 04:14:19 AM

Quote from: mamejay on July 27, 2011, 04:16:47 PM

I did not realise that they actuall;y made a white PAL PC Engine.

 They didn't. But there were companies that modded PC-Engine consoles for PAL.

Title: Re: Problem with AV Out PCEngine - strange daughter board
Post by: mamejay on August 01, 2011, 01:46:31 AM

That majority of parts that were removed I can get.  Its just a couple of caps which I do not know the vales of.  Anyone have schematics for a PCE where I can get the values?

Title: Re: Problem with AV Out PCEngine - strange daughter board
Post by: snow Crash on August 04, 2011, 05:24:34 AM

Hello Mamejay, sounds like we have the same problem!  Does this look the same? I think we've got some Hong-Kong converted PCE's

Title: Re: Problem with AV Out PCEngine - strange daughter board
Post by: mamejay on August 04, 2011, 10:21:12 AM

Yeah mine is the same.  Mine has has the original crystal removed and a few resistors.  I have used my multimeter on an unmodded board and it looks like all removed components are just resistors.  I will make a list of the removed components and see if we can reverse this mod.