Comments on: Philips Videopac G7000 (PAL) RGB Video Mod

By: MisthaLu

MisthaLu — Wed, 09 Nov 2016 10:53:31 +0000

My mate has been installing this mod in my G7000 for me, but we’re experiencing the strangest thing.
While the picture itself is very good, the colours are acting really strange: Purple becomes black. White becomes green. Red becomes dusty green.
The boot picture “SELECT SCREEN” seems fine regarding colours. For example, the purple colour in the “E” is fine. But when we start a game, the colours aren’t correct anymore. E.g. the purple background in Race is black.
This happens on any TV we connect to, be it LCD or CRT or even the X-RGB Mini Framemeister.

Does anyone have any ideas about this?

By: eddy

eddy — Thu, 11 Dec 2014 14:54:29 +0000

@xAD / nIGHTFALL
just as GamesX said … hummm … It seems to be not no easy with my SECAM machine … I see only one solution: to make tests on several pins with several amplifiers (with and without inverter)

bye

By: xAD / nIGHTFALL

xAD / nIGHTFALL — Thu, 11 Dec 2014 11:51:45 +0000

@eddy I takr the SYNC signal from IC679 (612160-3) Pal Encoder.

By: eddy

eddy — Thu, 11 Dec 2014 08:56:27 +0000

@xAD / nIGHTFALL

Hello,

first thank ou for your answer … but I disagree: even if I don’t know the purpose of the diode, the schematic of the SYNC amplifier is an inverter circuitry. So I expect that your SYNC signal is made with “down to up” pulses (the RGB signal, as composite signal, need “up to down” pulses”)

The SYNC signal is taken at the input of the PAL encoder, and not provided by the Video Encoder.

On the SECAM version of this game system (Radiola JET 25 or Philips C52) the video encoder provides a named CSY signal, wich is a “down to up” pulses. But this signal is not directly available on the main connector.
On this connector there is a synchro composite signal (up to down pulses) I think it may synchronize the RGB signal as well (but beed to be lowered)

So, before I begin to work, I wanted to have no doubt. Can you telle me where did you take the SYNC signal on the main board ?

Again, thank you.

By: xAD / nIGHTFALL

xAD / nIGHTFALL — Wed, 10 Dec 2014 14:02:44 +0000

@eddy

Hi Eddy

The exclamation saying ALERT.

You can use this signal only for the SYNC + R G B and not for Composite (VIDEO+SYNC).

By: eddy

eddy — Wed, 10 Dec 2014 08:36:24 +0000

Hello,
it’s me … again. I’m about to modify a C52 model. This french model is quite similar to PAL ones. There is non SECAM encoder directly soldered on the mother board, but a SECAM daughter board. Between these 2 boards there is a connector on which I can find RGB, Audio and LUM signals … there is a “Composite Synchro” Signal too. I think I can use this signal but GamesX schematic deals with !SYNC (this signal is inversed)
Which signal did you take into account ? What about the inversion ?
Thank you for the answer (you can answer by mail if you want)

Speak you soon.

By: eddy

eddy — Sun, 24 Aug 2014 09:13:34 +0000

Hello,

I’ve just finished my atari 2600 mod (french, with 8 colors … soon available on my blog) and this topic is my next project.
Thank you for the schematic, it will help me.

keep sharing your (very good) work on the net !

eddy