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NEC TG-16/TE/TurboDuo => TG/PCE Repair/Mod Discussion => Topic started by: Ergot_Cholera on January 19, 2016, 08:03:37 AM

Title: Core Grafx bad composite output
Post by: Ergot_Cholera on January 19, 2016, 08:03:37 AM

https://youtu.be/hRiCM6JLRnk
This is what I get from the din socket and also via my AV Booster.
 I have tested it with a Tennokoe 2 that I have RGB modded that uses pure sync and I get a perfect image.

Title: Re: Core Grafx bad composite output
Post by: thesteve on January 19, 2016, 09:11:37 AM

no luma
possible modded unit (svid)

Title: Re: Core Grafx bad composite output
Post by: Ergot_Cholera on January 19, 2016, 09:23:53 AM

It isn't modified. What is the cause of the lack of luma signal?

Title: Re: Core Grafx bad composite output
Post by: thesteve on January 19, 2016, 03:39:29 PM

well it should be coming off pin40 of the 6260 into a resistor ladder where it mixes with the other parts of the video sig

Title: Re: Core Grafx bad composite output
Post by: Ergot_Cholera on January 19, 2016, 09:06:19 PM

I already tried to trace it from the C6260, but I got lost through all the resistors and (transistors?). I will try tracing it from the other end. Nothing looks obviously damaged (but then it probably never does).
If I can't find an obvious solution that is simple enough for my lack of knowledge to comprehend then I will just use pure sync with an RGB mod.