PC Engine GT LCD Compositie mod

choijimmy · 09/07/2014, 05:53 PM

Hi,

Just tried my first PC Engine GT LCD compositive mod

Using following two reference -- one is from thesteve. ( Thanks thesteve !)

http://pcengine.freeforums.org/express-gt-composite-t179.html

http://blog.home108.com/

Eveything works well Except the screen has some noise / wave. Those noise/wave show up around every 5 seconds and very annoying. -- attached the pic

The picture I attached is much better than reality. Those noise/wave are hard to take photo.

Any one know how to fix / filter those noise out?

Thanks!
Jimmy

wolfman · 09/08/2014, 02:48 AM

Cool. What screen size did you use? 2.5"?

choijimmy · 09/08/2014, 03:02 AM

Quote from: wolfman on 09/08/2014, 02:48 AMCool. What screen size did you use? 2.5"?

3.5" lcd, it looks really cool except the noise/wave

choijimmy · 09/08/2014, 11:35 AM

more picture. Again, really hard to capture the wave/noise thru the camera.
It looks really cool with 3.5" LCD indeed

choijimmy · 09/08/2014, 11:35 AM

1 more

turbokon · 09/08/2014, 12:58 PM

Interference will cause it. Some of those LCD boards are more prone to interference then others.

choijimmy · 09/08/2014, 05:13 PM

Quote from: turbokon on 09/08/2014, 12:58 PMInterference will cause it. Some of those LCD boards are more prone to interference then others.

Ic. Thanks a lot!!

turbokon · 09/08/2014, 07:14 PM

Also bad grounding in the composite circuit can it too.

choijimmy · 09/08/2014, 07:14 PM

Quote from: turbokon on 09/08/2014, 12:58 PMInterference will cause it. Some of those LCD boards are more prone to interference then others.

I think I will leave it for now because I glued the lcd boards hardly with all the wires, lcd panel, etc... lol

really appreciate your help!

turbokon · 09/08/2014, 07:14 PM

Also bad grounding in the composite circuit can it too.

choijimmy · 09/08/2014, 07:45 PM

Quote from: turbokon on 09/08/2014, 07:14 PMAlso bad grounding in the composite circuit can it too.

Just resolder the ground contact point and even tried to find another ground spot on the GT mainboard spot. Still No luck... still save wave/noise on the screen. For the LCD board, the grounding point is so obvious, resolder it but also no luck. I "guess" may not due to grounding issue

choijimmy · 09/08/2014, 09:50 PM

After further testing, I am pretty sure it is due to interference. The reason is I found if I put the LCD part ( the front part of the case ) --> the GT main board ( the back part of the case ), there is discolor issue ( light blue change slightly to very light green )

Thanks a lot!
Jimmy