Atari2600 4Switch NTSC RCA displays Black & White on EURO TV

[retroborg]

Good day!

I have an Atari 2600 4-Switch Darth Vader NTSC PCB CO15519 REV 16 (C) 1980



On which I performed the Composite RCA AV Mod as described in this Link:

http://retro.mmgn.com/Atari-2600/For...ri-2600-AV-Mod

I specifically used the following components and connected them to 2 RCA Jacks as I did on my other PAL Atari 2600 4-Switch console.

"Green TIA Pin 2 (Sync): Direct to video
Yellow TIA Pin 5 (Lum 1): 1k Resistor
Yellow TIA Pin 6 (Lum 2): 220 ohm Resistor
Yellow TIA Pin 7 (Lum 0): 1K Resistor

Red A is for Audio
Blue C is for Color

Pins A and C don’t need any components but you can use\should put a 100p ceramic capacitor on Blue C. Both A and C will then go directly to you RCA jack's."

Everything works fine and the display is much clearer in relation to the RF output without distortions, however both the RF & RCA output only display in black & white on my EURO CRT 21" SONY TV KV-21FQ10 which is more than capable of display in in colour at 60HZ as it suppots PAL-60 and all my other modded consoles play fine on it with color via RGB Scart.

Is this natural because this is an NTSC console, or is it something which I’ve done wrong, or is there a problem with this specific console?
I note that the RF Output displayed in black & white even before I performed the RCA mod, but I thought it would be OK with RCA.

By the way, this specific PCB has this weird circuit enclosed in a huge plastic block like a brick, which is connected on various points on the PCB which I do not recognize their use. I have no idea of its purpose nor have I ever seen anything similar before.

I considered removing it, but decided not to in case it replaces / fixes some defective components or IC on the PCB and has been added as an external fix.

Could this be causing the black & white display?

http://s1356.photobucket.com/user/re...?sort=3&page=1

Any help will be highly appreciated
Thanks in advance

[Ferral]

Your best bet with this one with working on an NTSC machine is ask over on Atari Age or Atari Forum. I have a feeling it will be either something to do with your TV or the fact that the machine itself is NTSC, does your TV have more than one scart connector, if so try connecting it to the other one. One of my CRT TV's are like this with my Atari ST, outputs in B&W (even though it is a PAL machine) on one of the scart sockets but fine on the other.

I personally prefer Atari Age as it covers a wider selection of areas all retro related and I find the community a bit more welcoming, Atari Forum is still a great place but it is full of people that are more into the heavy technical stuff so head there if no one at age can help.

http://atariage.com/

[retroborg]

Your best bet with this one with working on an NTSC machine is ask over on Atari Age or Atari Forum. I have a feeling it will be either something to do with your TV or the fact that the machine itself is NTSC, does your TV have more than one scart connector, if so try connecting it to the other one. One of my CRT TV's are like this with my Atari ST, outputs in B&W (even though it is a PAL machine) on one of the scart sockets but fine on the other.

I personally prefer Atari Age as it covers a wider selection of areas all retro related and I find the community a bit more welcoming, Atari Forum is still a great place but it is full of people that are more into the heavy technical stuff so head there if no one at age can help.

http://atariage.com/

So, it would seem there was a much easier solution. I simply rotated the pot on the PCB a few degrees and the color magically apeared!
With some trial & error I settled at a spot where all my games look ok, with color on my TV. However the colors do look a bit different compared to the other Atari 2600 consoles I've modded.

Thanks for the info none the less!

By the way, does anybody have the slighest idea what that huge block of hard plastic encloses inside and why it's connected on to the PCB?!

I would like to X-Ray it!

[Ferral]

At a guess it could be where the power goes into the machine to cover components that could give a nasty nip if touched or something to do with the RF Modulator, maybe some sort of shielding to stop interference.

[retroborg]

At a guess it could be where the power goes into the machine to cover components that could give a nasty nip if touched or something to do with the RF Modulator, maybe some sort of shielding to stop interference.

Doubtful. The connection on the PCB leading inside the plastic block don't look factory made. This was obviously added at a later time by someone, for reasons unknown.

I think this probably fixes some defective component on the PCB...

Either way, there is no way to open it with simple tools, as it's rock hard and any atempt would probably ruin what ever sinister circuit lurks inside!