Help! Atari 2600 colour + other problems

[Wilde Bill]

Hi all, first time posting, great fan of Atariage, sorry if I'm posting this in the wrong section and apologies if I sound like a luddite about this:

 

I have a PAL light sixer that I play on a PAL CRT TV. Since I got it the console has been perfect, I play it every few days, both PAL and NTSC games, the problems started when I turned it on this morning:

 

To begin with it was very hard to get any game running (I clean my carts and cart-slot regularly) and have never had a problem before, instead of just starting on powerup, I got black screens for every game, I had to clean the cartridge slot (i.e inserting a cart that was wiped with cleaning alcohol and leaving it inserted for a few minutes) a number of times before I could get any game to work and after a few insertions I would only get black screens again.

When I am able to get a game to work there are a number of problems, the most obvious one being the colours are off; so when playing an NTSC version of Berserk, the start-up screen saver displays colours I've never seen before, like dark red, dark green or black, and Evil Otto, the Main Character and the shots he fires are a kind of sickly green (they are usually a bright pink), after a few minutes of attempting to play the colours will then shift from black and white, to a horrific rainbow like interference, before going to a black screen - a point of note, while the Otto and the player are no longer pink, the colour pink is still visible on the score and walls, so it's still seemingly available.

On a NTSC Mountain King cart, the colours initially seem fine, but upon playing they will either shift to black and white, or the floors will change colour every time the character is made to jump.

On a PAL Yars Revenge cart, Yar has a sickly green colour or the game will flicker out or go black and white.

On an NTSC Raiders of the Lost Arc, the backgrounds of some of the screens are totally different colours, (so blue instead of green or pink instead of grey)

I'm sorry I've no photos here, it's really hard to get any game to run at all (I've spent the entire morning at this and am at my wits end),

I've tried everything that I'm able to do; I've eliminated the TV as a problem, (trying my Atari on another TV and testing the TV with DVD players etc), it's not interference from the joystick (I've tested a Wico along with original controllers, I never use anything else),

I've re-tuned the Atari a number of times on two TVs and the same problems persist,

I've disconnected and reconnected everything (including the main cable by taking the top off the Atari), all ports are good and tight, the power supply is new and matches original specs, in short everything has worked perfectly for months without a problem until this morning, I'm just at a loss (as you might be able to tell, I have very little electrical skills). I do know about the Atari colour pot, but I'm afraid to touch it, as nothing has happened that would have caused it to move and I'm afraid to make the problem worse, the atari sits on a wooden stand infront of the TV, I have a bubblewrap dust cover when not in use.

One point of note; is there a chance that a faulty powerswitch could cause this? I only ask because some of these problems might accentuate if I tap the switch but it's hard to tell if I'm just imagining this, because the games don't last long before they go to black screen, the switch has always been very stiff, a great deal harder to move than any other of the 6 switches, the others can be flicked quite easily, should this switch have the same give as a light sixer difficulty switch?

I've searched through these wonderful forums and another possibility keeps coming up about solder joints sometimes causing similar problems, can anyone describe what such a problem might look like? Or if there is a way to rule out things?

Sorry for this long post, or if I've stupidly put it in the wrong part of the forum, thanks to anyone who can give any help,

 

Edit:

Since writing this, it now seems to just come up with a black screen for every game alas

Edited September 25, 2015 by Wilde Bill

[Wilde Bill]

Sorry to add this, I realised I can no longer edit the above, I do have a harmony cart on the way in the mail, would anyone know if there is any Test Cart/Diagnostic cart software I could use on this to perhaps determine what the problem is? If there was something I could put on it that tests ram etc like the cart for the original atari field manual? - just putting forward any idea I have

[zylon]

Change the voltage regulator first. If the colors change after it heats up, then it is failing and will take other components with it.

[Wilde Bill]

Hey thanks Zylon,

I did a few more tests yesterday (I've since unplugged everything until parts arrive). What's weird is that I get black screen for the first few minutes, and then the game will work, but with the strange colour thing, but the picture itself is crystal clear, the only new thing I noticed was the flicking the BW/Colour switch causes the colours to shift, not to go to black or white, but change in hue; I opened her up yesterday and noticed the 2200uf 16v cap was bulging quite considerably, seen as I would need to order one of those anyway I just sent an email to best elec. to get a full suite of small parts including the regulator you mentioned. I also have a Harmony Cart in the mail and I only just realised that if the problems persist after those two things are replaced I can try to run the diagnostic cart rom with the Atari field manual seen as console can still just about work.

Rest assured I'll post up whatever I happen to find out if I can get my light sixer working properly again,

[Wilde Bill]

Update! Problem fixed!

Hey all, finally got around to fixing the Atari, the problem was the 2200uf 16V axial capacitor (which had finally gone bad after 37 years of use), I replaced that and it worked perfectly first try, the picture is crystal clear now and the colour is back to perfect, I'm glad I originally didn't touch the colour wheel.

Hopefully no more problems for a while,