19 replies to this topic

[Redcurrie]

I just got a MIB 4-switcher from the original owner and when I cut it on, I get the correct picture on the screen for about a second and then it goes to a solid color. Any suggestions for what may be the problem?

Thanks,
Laura

[Brad2600]

Try cleaning out the carts that you are putting in it or the cartridge slot itself?

A little rubbing alcohol on the edge of the cartridge slot usually works for me.

[Nukey Shay]

Maybe it could be that the power adapter isn't putting out enough amps? What does yours say on the adapter?

[Breakpack]

Also try canned air.This stuff's great

[Ian Primus]

Erratic operation can be caused by many things, most of which are bad connections. Try cleaning the cart, and the cart slot. To clean the cart slot, I generally use a folded bit of thin cardboard, like a business card or an index card, and gently push it into the cart slot. You'd be suprised how much dirt accumulates on those connectors. For cleaning the carts, use a Q-tip with isopropyl alcohol, and rub along the contacts. You may have to push open the dust flaps on both the cart and the console with a small screwdriver or a paper clip. Also, wiggle the switches on the console back and forth, especially the power switch, the TV type switch and the channel select switch, to make sure that they are making good contact. Try the system with some known good carts, and a known good switchbox. Those can cause problems as well, and I would reccomend using the RCA to F connector adapter instead. Also, try it with a known good power adapter. If the adapter isn't putting out enough current, strange things happen. I know that when I had the Atari running off batteries, it was pretty funny when they started to wear down. The scan lines in the picture get out of sync, and the sound gets garbled and slow.

Ian Primus
ian_primus@yahoo.com

[bjk7382]

Ian Primus said:

I know that when I had the Atari running off batteries, it was pretty funny when they started to wear down. The scan lines in the picture get out of sync, and the sound gets garbled and slow.  

What would you run it off, a bunch of 9 volts hooked together in sequence?

[Ian Primus]

Quote

What would you run it off, a bunch of 9 volts hooked together in sequence?

Well, I have powered the Atari from several different forms of batteries. The first time, I used two 9 volt radio batteries in parallel. That works well, but only for an hour or two. During the blackout, I was without power for two days, and I really didn't want to have to go out, so I ended up using a bunch of D cell batteries (stolen from flashlights) in series. I just duct taped them end to end, and then taped the leads to either end, and fed them into a phono plug for the Atari's power. I found that seven "D" batteries will last quite a while (several hours, I forget how long exactly). Then when I was at the store the next day getting supplies, I bought two 6 volt lantern batteries, and used those in series. Those lasted a LONG time, and I never did drain them. I still have them on the shelf, just in case... Keep in mind that the Atari can take a large range of voltages, and a couple volts higher than 9 is fine (theoretically up to 35, but I have not tested that...), but once the voltage drops below 7 or so, the Atari stops working properly (it doesn't hurt it, it just won't work with that low a voltage). Current is also important. The Atari draws about 300mA, so you'll use up the tiny radio batteries much faster than larger, higher capacity D cells.

Ian Primus
ian_primus@yahoo.com

[Redcurrie]

Okay, I have other systems so I know that my power supply, carts and TV connections (I don't use a switchbox) are okay so I've ruled those out. I've also wiggled the hell out of the switches and cleaned the cartridge slot. I think that this clue may be the key because when I put in Kaboom, it essentially looked like the picture dissolved from left to right and I'm left with the screen divided into the correct color blocks with no guy up top and some evenly-spaced, thin black lines on the left side of the screen. I don't know crap about this but I saw something in another post where someone commented that they could see the "RAM refresh" cycles on the left of the screen......I guess that what has me confused is that this unit is mint and doesn't work and the dozen others that I've gotten that looked fresh from being dug out of the yard did work! I even gave the older guy that I bought it from a fair deal so it can't be bad karma. I'm starting to think that we might be rapidly approaching screwdriver territory....

Thanks!

[Ian Primus]

Quote

I don't know crap about this but I saw something in another post where someone commented that they could see the "RAM refresh" cycles on the left of the screen......

Heh, that. I am assuming you are referring to my thread in the 5200 forum about a damaged Space Invaders cart. I managed to fix that tonight. I took the cart apart and really cleaned the connector. It was filthy! I had tried cleaning it with a q-tip, but it didn't help, I had to disassemble it and scrub the contacts to get them clean. It works fine now. It almost sounds to me like a dirty or bad cartridge connector, although I have _never_ seen that happen on a 2600. It was really common on the NES, since the CHR and PRG ROMS are separate, on separate chips, so a dirty cart would sometimes screw up CHR access, but not PRG, so the program loaded fine, but all the graphics were screwed up. Every dirty 2600 cart I have seen just gives hum bars or a blank screen, never have I seen garbled graphics. Could be that the TIA in the console has failed, or one of the other related chips, but you say that you get the proper picture for a second on some carts, but screwed up graphics on Kaboom!. I would suggest thoroughly cleaning the cart connector. Unfortunately, there isn't really an easy way to expose the bare connector, since the dust flap is part of the connector, not the case. Try cleaning it again with the cardboard, or maybe with a little alcohol on the cardboard. Also, check to make sure none of the pins are bent or damaged. Could be that you've got a short in there somewhere, or a pin that isn't making contact.

Ian Primus
ian_primus@yahoo.com

[Redcurrie]

[quote="Ian Primus"][quote] Every dirty 2600 cart I have seen just gives hum bars or a blank screen, never have I seen garbled graphics. Could be that the TIA in the console has failed, or one of the other related chips, but you say that you get the proper picture for a second on some carts, but screwed up graphics on Kaboom!. I would suggest thoroughly cleaning the cart connector. Unfortunately, there isn't really an easy way to expose the bare connector, since the dust flap is part of the connector, not the case. Try cleaning it again with the cardboard, or maybe with a little alcohol on the cardboard. Also, check to make sure none of the pins are bent or damaged. Could be that you've got a short in there somewhere, or a pin that isn't making contact.

Ian Primus
ian_primus@yahoo.com[/quote]

I know that it is not the carts as I have seen all of the malfunctions that you described as cart-related. I get the proper picture for a second with all of the carts including Kaboom!; as its graphics are on the left-hand side, it was the one that seemed to allow me to see the image "melt" from left to right. The others just appeared to go from picture to solid color and I couldn't tell what happened. I did the business card in the cart slot cleaning thing (I knew business cards had to be good for something else other than putting in fishbowls to win free lunches) and got a little dirt out but still had the same problem. Maybe what is deceiving me is that this unit is SO clean as it has been boxed for 15 years or so and looks brand new. The pins look fine (from just viewing them from the outside) but I'm going to work a bit more on it tonight. Thanks for everyone's continuing help!

Laura

[Ben_Larson]

I've seen garbled graphics on a 2600. I have an Enduro cart which is kinda dirty- I was playing it the other day and the bottom part of the screen started jumping from left to right, then the graphics went completely FUBAR and the top part of the screen started looking scrambled, like watching a scrambled cable TV picture. Then I turned it off, cleaned if off some more, popped it back in and everything was fine...

Ben

[Ian Primus]

Another thing to try would be to inert a cart a little crooked, or not fully seated. As strange as this sounds it generally works. Push the cart in all the way, then pull it up and to the left or right just a little, not enough to remove it from the machine, but enough that it sits in there, while still making proper contact. This works because sometimes when the pins in the console get worn down, they no longer make contact where they are most often used, but if you put the cart in a little crooked, the cart's connector makes slightly different contact with the cartridge slot, and this can sometimes work. Once again, I have seen this very often in old NES decks. NES machines (the front loaders especially) were very prone to this, as the connector pins in the deck wore out quickly, and were frequently damaged by people using Game Genies. While the Game Genie is a cool little device, the board is actually thincker, thus allowing it to make proper contact with the NES even though the Game Genie can't be clicked down into position when it has a cart in it. The wider board wears and stretches the contacts in the deck, so before long, it becomes difficult to get games to play without the Game Genie, and eventually, you get a "blinking deck" that refuses to work period. Like I said, I have never personally seen this happen to 2600's, but I would assume that it is possible, especially if it was used a lot, or if it was sitting for a long time in a moist environment, therefore corroding the connector pins. Don't be decieved by the outer appearance, it could be that the machine was packed away 15 years ago because it didn't work!

Ian Primus
ian_primus@yahoo.com

[Christophero Sly]

I would guess that you have a bad voltage regulator or a shot TIA.

[Redcurrie]

Christophero Sly said:

I would guess that you have a bad voltage regulator or a shot TIA.

Is there an easy way to test either of these. I have a number of working consoles that I could use for donor test parts if someone could give me directions on what to do. If I could narrow it down to which is the problem, I'm sure that I could scavenge a replacement part from someone. I'm not an electrical wizard but I am pretty mechanically inclined.

Thanks!

[Redcurrie]

Ugh, there's no other way to describe it but the image of the game on the screen appears to dissolve. This is SO frustrating! I threatened it with a screwdriver but no luck.....

[Ian Primus]

You could try swapping parts with another working Atari. There are only really three main chips in a 2600, the RIOT, the 6507 and the Stella, aka TIA. In most units, these are socketed, so you could try swapping, one chip at a time, from a working Atari into the broken one. Of course, you should measure all the voltages first, and make sure that nothing will fry your good chips. I would start with the TIA, since it seems the likely culprit. It should be the chip on the bottom, furthest from the cart slot.

To take apart the 2600, you'll have to remove the four screws on the bottom, and then separate the halves. Then, carefully work the circuit board out (The difficulty switches like to catch on the case) Once you have the board out, thread the RF cable out of the case, or disconnect it from the board to make it easier to work on. Take the RF sheilding off from the board by straightening the bent tabs with pliers, and separating the halves. You'll probably have to un-stick the silvery tape that goes across the top, between the sheild and the switches.

If you need help, I can post pictures of the process.

Good luck!

Ian Primus
ian_primus@yahoo.com

[Redcurrie]

Ian Primus said:

Of course, you should measure all the voltages first, and make sure that nothing will fry your good chips.  

Good luck!

Ian Primus
ian_primus@yahoo.com

Okay, I have two of them open and have IDed the TIA. What is the easiest way to pop the chip out without breaking anything? Are the "teeth" on the sides part of the chip or are they what is holding the chip in? Also, I have to go to get a voltmeter from Radio Shack (and some parts to fix my trak-ball as I think I've IDed its problem). As I want no chip frying, how (and where) do I check the voltage? E&M in Physics lab was a while back.........

Thanks for all the help and patience!
Laura

[Ian Primus]

Well, it depends on the machine, but the chips _should_ be socketed. The "teeth" are the chips's pins, and they should be plugged into a socket. If they lead directly into the motherboard without going into a flat black block, then turn your system over to an experianced repairman. Those chips are _really_ hard to remove if they are soldered to the board (which they shouldn't be, but you never know). Before removing the chip, note the orientation of the notch, which indicates pin 1. To remove the chip, insert a thin, flat object such as a butter knife or a small flathead screwdriver between the chip and the socket at one end. Lever the chip up a tiny bit, and then repeat on the other side. Do this until the chip is free. To insert a chip, line the pins up with the holes in the socket, and gently press it until it starts to slide in, making sure that all the pins are going into the holes, and not bending out or in. Press firmly until the chip is seated.

A couple of tips:

Don't force the chips out of or into the sockets. You don't want to bend or break off pins.

Don't use one of those "IC Extractor" tools that Rat Shack sells. It's not going to help, and often makes the problem worse, since the chip will suddenly pop loose at one end and not the other, almost always resulting in bent pins.

Always remember the orientation of the chips. There will be a notch in the chip in the form of an indentation on the top, an indentation on one short side, or a large cutout on the top of the chip. You'll know it when you see it. If you're paranoid, mark the tops of the chips with a pencil.

Careful of static electricity. You don't want to zap your any of the chips. Ground yourself by touching the screw on a lightswitch cover, or the metal case of your computer.



To check voltages, get a multimeter, and test at the cart slot, and at the voltage regulator. Put the common lead of the multimeter on the place where you took the RF sheild off (that wide silver square, that's all ground). Then test the positive lead of the multimeter on cart slot and voltage regulator. Pin 23 on the cart slot is +5, and is the second from the upper left looking down into the slot from the front. I would suggest testing on the back of the board though, it's easier to get to. IIRC, on the voltage regulator, +5 should be the pin closest to you, looking at the board from the front. Or, the one on the right looking at the voltage regulator with the screw hole to the top. All voltages should be five volts, or very close to it. If your regulator is putting out the right juice, but the cart slot reads really low, then something is loading down the circuit. If the voltage regulator reads about nine volts and the cart slot measures five, then you measured the wrong pin on the voltage regulator...

If you are confused, I can take pictures.

Ian Primus
ian_primus@yahoo.com

[Redcurrie]

You guys are awesome!!! I checked the voltages and everything was okay there (thank heavens because that voltage regulator seemed like it would be a bit more challenging to change). I switched out the TIA and voila, a working 2600. Between fixing this and the Trak Ball, I feel like I have accomplished and learned a whole lot this weekend. Now for the big question, where can I snag another TIA to replace in my other unit?

Thanks again SO much for the help and detailed directions!!!

Laura

[CPUWIZ]

Redcurrie said:

Now for the big question, where can I snag another TIA to replace in my other unit?

One NOS CO10444D coming right up.