PAL Intellivision- Wrong colours

[Swainy]

Hi all, I've kindly been given an Intellivision by a friend. However, the colours do not appear to be displaying correctly.

 

http://i1376.photobucket.com/albums/ah35/swainy75/4F86228D-7174-45E3-8750-25D5168BAF71_zpsfvg5466z.jpg

 

http://i1376.photobucket.com/albums/ah35/swainy75/5AC9CA8E-8330-404F-8B54-B851FA91CBA4_zpsryylfyle.jpg

 

Any ideas as to what could be causing this?

[mr_me]

If it were a north american intellivision I would say check the AY-3-8915 chip and the circuitry between it and the rf modulator. But in a pal intellivision that chip is replaced with a set of chips, sometimes on a daughter board. So inspect the left side of the main board (or daughter board). Clean it, maybe dirt is causing a short. Check for bad solder.

[Swainy]

Cool, I'll get it opened up!

[HunterZero]

You may have a grounding issue with the RF output, or some other short.

 

When you disassemble the unit, check if the shielding has been removed or not.

 

There are 2 adjusters you can get to without opening the shielding, one is for audio and one is for video:

 

 

If the video adjustment doesn't help, you'll need to crack out the soldering iron and open the shielding. Check around and inside the RF modulator (the lid clips off) for solder bridges or cracks.

 

Most PAL model 3668 Intellivisions have a daughter board that does the colour generation as mr_me says. There are ribbon cables that connect where the AY-3-8915 would go to the daughter board, check these for continuity. The daughter board contains a couple of adjusters on it, and a number of electrolytic caps. The SHOEI caps in Intellivisions are generally good quality, but still at least a visual check for leaked caps is a good idea. You could try replacing the 4.43361875 MHz crystal, as this is the one that generates the PAL colour frequencies (the PAL Inty should have 2 crystals - one at 4MHz for system clock, and one at 4.43361875 MHz for colour subcarrier).

 

Check too that the power supply voltages are correct, in particular the 12V across the back 2 pins on the power supply.

 

- J

[Swainy]

Thanks for the info! I haven't had a chance to open it up yet (I work nights ) but I'll have a look this afternoon.

[Swainy]

Ok,so I've opened up the console, no shielding...

 

http://i1376.photobucket.com/albums/ah35/swainy75/68725CB4-6996-4D95-BBD8-33A0446507EE_zps4gk6mzhx.jpg

 

I've not got a multimeter handy so I've had a play with the adjusters on the daughter board, I've managed to get the in game colours to what looks correct from what I can tell in Astrosmash and a couple of other games.

 

http://i1376.photobucket.com/albums/ah35/swainy75/27ADB44C-C4C3-497A-AF80-3FEBD5D4CE4E_zps3pvc4dne.jpg

 

However the title pages are still red rather than green.

 

http://i1376.photobucket.com/albums/ah35/swainy75/695D33B2-E54B-4D98-84BE-9FE0C5650DB5_zpssusbgo0z.jpg

 

So I'm not sure if the colours were different on European systems or if there is actually something wrong with it? Edit, just seen some PAL footage. It should be green.

Edited July 4, 2017 by Swainy

[mr_me]

I don't think there are white meteors in Astrosmash, unless tan is looking like white in your photos. In the titlescreen the second color block should be yellow and the fifth should be tan. In your photo yellow and tan look white. The titlescreen background is technically called brown although it normally does look green. Red, blue, black, white, and the two greens look okay in your titlescreen photo.

 

Edit: How did you fix the other colours? It looks alot better than the title screen photo in your first post.

 

Do you see anything visibly wrong on the circuit board?

Edited July 4, 2017 by mr_me

[Swainy]

Mmm. I don't suppose that there is anyone in the Essex area of the UK who can repair these are there? I'm hopeless with a soldering iron.

[Swainy]

So after speaking to retromodding.de they seem to think that the UK Intellivision's did have a black title screen.

 

[decle]

So after speaking to retromodding.de they seem to think that the UK Intellivision's did have a black title screen.

 

 

I'm afraid not. While title screens from other manufacturers, noteably Coleco, did have a black background, standard Mattel title screens are a lovely poo brown on PAL Intys (sorry for the poor picture, it was the only one I could find on the net, and my Inty also has colour problems):

 

 

I think that officially the colour should be rendered as brown, but NTSC renders it as drab green of some reason, Joe mentions it here, but I'm sure I've read a better explanation somewhere.

Edited July 25, 2017 by decle

[Swainy]

Well I think that's pretty much what mine displays. When I started this threadI thought that the title screen background should be green as it was what I had seen on YouTube. I never owned an Intellivision until recently.

[mthompson]

Seems like Mattel thought it was going to be brown, too.

 

[+intellivotion]

 

 

I'm afraid not. While title screens from other manufacturers, noteably Coleco, did have a black background, standard Mattel title screens are a lovely poo brown on PAL Intys (sorry for the poor picture, it was the only one I could find on the net, and my Inty also has colour problems):

 

I think that officially the colour should be rendered as brown, but NTSC renders it as drab green of some reason, Joe mentions it here, but I'm sure I've read a better explanation somewhere.

AFAIR, all my standard Mattel games have a green background in the title screen on PAL consoles and tv's

[mr_me]

That old football graphic looks more maroon than brown. To the stic chip its colour 11 and in the GI documentation 11 is brown. The stic just produces a four bit colour code (0-15) and doesn't define any colours. That is done with the ay3-8915 colour chip for ntsc and various circuits for pal and secam; so there could be some variation (and ntsc stands for "never the same colour"). And then there are emulators and RGB mods where the programmers have to define their own colours, although most emulators seem to use the same standard.

 

Swainy's picture looks okay, much better than before. As long as you can tell the difference between white, yellow, and tan because its hard to in the images. In the first image posted most of the colours were screwed up, not sure what you did to fix it.

[HunterZero]

My PAL 3668 unit gives the standard olive green-brown colour for the title screen background, the same as the NTSC version. I did notice that Thunder Castle when played on a USA unit has a black title screen background, while the PAL Intellivision displays the the default olive colour. However when I changed one of my units to a PAL60 unit, the background changed to black, so this appears to be game timing related, not to do with colour circuitry.

 

There look to be three trim pots on the daughter board on top. I'm pretty sure that is the colour board that generates the video signal. Have you tried the adjusters on this top board? Maybe a previous owner twiddled those pots?

 

Can you get a better detailed pic of the front and the back of the daughterboard that's on top? That would be the colour board. Especially useful would be chip numbers. Or better yet if someone has a schematic...