Atari 2600 4-switcher, intermittant fuzzy reception

[Andromeda Stardust]

Hi. I I've been lurking around Atari Age forums for a few weeks, but I need help with a 4-switch Atari 2600 console I recently aquired. After years of retro colecting, I have finally purchased my first Atari. I originally posted about it on NintendoAge, but perhaps the people on AtariAge may be more knowlaedgable about Atari systems. Here is the original thread:

http://nintendoage.c...&threadid=76826

 

Basically, what frustrates me is that that for the first 15-20 minutes of game playing, the signal is crystal clear, then very suddenly the reception becomes fuzzy. If I toggle the power switch, the reception becomes crystal clear again, but inevitably, I get the snow again with continouous gameplay. It can be really anoying when the display does this in the middle of a game, and if the game uses colored backgrounds, it can make the display almost unwatchable. I also modded my console to use Coax TV cables instead of RCA, which did result in a cleaner image on channel 2-3, but ultimately, the problem remains: I play the console for a while with clean picture, then the reception becomes fuzzy. I've also cleaned all of the switches and contacts, and I was hoping someone at AtariAge may have some answers or suggestions for me to try.

 

Rather than retype all of my old posts, I have quoted them from the old thread at NintendoAge. Sorry if it's a little wordy...

 

I recently purchased an Atari 2600 on eBay, and the console is pretty fun at times. It has the four switches with the wood grain inlay. I had a blast playing VideoOlympics (PONG remake) and numerous other titles. One problem with the console, is that after 15-20 minutes of play, the picture becomes fuzzy. If I reset the game console by toggling the power switch, the picture is clear again, but it eventually soccums to fuzz again. It seems the color signal gets messed up. I've tried switching between channel 2 and 3, but the fuzz is not eliminated. I don't believe it is the cable. The seller that sold me the console replaced the original cable with a cheap RCA cable, which I have replaced with a premium shielded shielded cable for optimal signal quality. There is an RCA jack soldeired directly to the motherboard; I do not know if the jack is original or not. I have an elbow connector plugged into the jack because otherwise the premium cable wouldn't fit. The shielded cable did make the TV picture noticably clearer, but I still get the same symptoms where the first 10-15 minutes of game play are crystal clear, then signal gets snow and the picture is messed up. I may upgrade to a coax TV cable, but I don't think the problem is the cable itself. Giggling the cable does not correct the problem when the picture goes wonky, but toggling the power switch immediately fixes it. I don't really think it's a heat issue, because if it was, the electronics would still be warm after the power toggle, but I don't want to lose my progress by turning off the console. Also, it doesn't gradually get worse, but suddenly goes from a clear picture to a fuzzy picture, and stays that way until I turn off the console, but only after I've played it for quite a while.

 

Any suggestions on how to prevent or repair the fuzziness on the RF output? Should I attempt an AV mod? I am quite handy with a soldering iron btw.

Yeah, that's the funny thing: it's not really intermittent. The picture is crystal clear until I've been playing it for a while, then like halfway through a PONG tournament or other game, the screen goes fuzzy, and it's not white noise static like what you get with a weak TV signal. There's very strong RBG color components in the snow, as in the snowy pixels are actually red-green-blue colored. I connected the Atari to the HDTV in the living room and left the Centipede screen run for a while, and I didn't see any wierd behavior. The Sanyo HDTV picture is actually very clean, compaired to what most people are saying about retro analog console + LCD TV performance. I have a feeling that the interferance may be caused by the static buildup off the old CRT TV screen. The old early 90s tube TV has a beautiful picture and a big screen, but I don't really have room for it atm. It's also currently my only option for playing Zapper games. The TV is on a small table and the Atari console was resting on the corner, because there was barely any room for it. Anyway, the console was literally inches away from the tube, and IMO it's probably not wize to place any kind of digital electronics that close to a tube. Like many old tube TVs, you can hear the crackle of the static charge as soon as you turn it on or off, and it raises the hairs on my arm when I get close to the screen. I've heard stories of the old 4-switch Ataris dying from static electricity due to the reduced shielding, so it's probably not a wise setup at all, having the Atari butted up against the base of the TV. I'm also thinking about placing a torroidal RF choke on the video cable as well to see if that helps.

Well, I moved the Atari farther away from the TV set by setting it on a chair. I left it turned on with Ms Pacman title screen for a couple of hours, and it never went fuzzy again. I'll wait and see if it ever does that again. For the time being, I'll make sure it stays at least 2-3 feet away from the old tube screen. I'm probably lucky I didn't kill the Atari by pressing it against the TV. If I see the snowy reception again, I'll check for cold solder joints.

 

As far as reception goes, it appears that the Atari brand RF switch doesn't work the same way as the NES/Genesis ones. I have an NES RF switch connected between the LCD set and the cable box. When I connected the Atari to the NES RF switch (I misplaced the Genny I AV cable, so I've been using the RF switch on the HDTV), I got nothing but static on the TV screen, but with the RCA/Coax adapter connected directly to the TV set, it worked flawless. However, that necessitates disconnecting the cable box, which is a pain.

You may have a point. I get sparkles on the screen whenever I flick the spring-loaded Game restart and Game mode switches, and those suposedly aren't even associated with the display circuit. With the "mode" switch, sometimes it skips over several the game variation numbers when I flick it, which is annoying if I'm scrolling through 50+ game modes and it skips the one I want (yes, I'm looking at you, Video Olympics). A decrement option would have helped a lot. The Color/B&W switch I have no use for since all my TVs are color, and I have a feeling feeling not too many people used it, as it seems only the earlier released games (pre-1980s) support it.* Maybe I should spray the RCA jack on the bottom as well. Channel 2 seems a little cleaner than channel 3, but that may have to do with how accurate they're tuned. Both channels have very clear picture. There appear to be a couple of pots on the board, but I'm not brave enough to mess with them.

Well, I did some minor modding on my Atari console. I completely stripped out the RCA cable and sprayed all of the switch contacts with a can of electric contact cleaner I purchased at Radio Shack. The switches seem to have a lot less resistance and feel very smooth now. It also seemed to solve much of the bounce back problems that I had with the mode switch. I also sprayed the cartridge connector and worked E.T. in and out of the cartridge slot a couple of times to clean the contacts. I also sprayed the little RCA jack on the motherboard as well. I decided to install a permanent Coax cable jack on the back of my console, so I used a right angle RCA-coax adapter and a 1 ft coax TV cable inside the console. Then I drilled a 3/8" hole in the back and connected a coupler in the console wall. I also added a green power LED (rated 12V) to the front of the console and connected it between the ground trace and the other side of the Power switch, so it operates on 9V and glows brightly lime-green whenever I have the console powered on. It's pretty nifty looking, as all of my other modern/retro consoles, from NES to Wii also have power LEDs.

 

I thought all my woes were over with, and the picture on NTSC channel 2 is about as pristine and crisp as you can get for an RF modulation circuit without a pre-emphasis filter. There is still a tiny amount of horizontal bleed on the edges of shapes with the old CRT TV, but that is just an intrinsic part of the RF signal. Somehow, the bleed through nearly disappears on the Sanyo LCD in my living room. Unfortunately, believing my display woes were over with, I began playing last night on the CRT, and after about 20 minutes of Ms Pacman, the signal fuzzed up again. It also exhibited the same behavior after quite a while playing Pitfall II. It's stupid-easy to die in that game and lose all your gold. Just like before, the fuzziness immediately goes away when I toggle the power switch. I will be attaching pictures shortly.

 

Power LED and Coax mod:

http://nintendoagemedia.com/_usermedia/attachments/Atari%20front%2Ejpg

http://nintendoagemedia.com/_usermedia/attachments/Atari%202600%20back%2Ejpg

 

Clean reception (colors are fine but appears oversaturated because the screen is bright and my cell phone doesn't take good TV screenshots):

http://nintendoagemedia.com/_usermedia/attachments/Clean%20screen%2Ejpg

http://nintendoagemedia.com/_usermedia/attachments/clean%20screen%202%2Ejpg

 

After 15-20 minutes of continuous gameplay, the screen suddenly becomes fuzzy and looks like this:

http://nintendoagemedia.com/_usermedia/attachments/fuzzy%20screen%201%2Ejpg

http://nintendoagemedia.com/_usermedia/attachments/fuzzy%20screen%202%2Ejpg

 

It's not the CRT static as I originally thought. The game console is several feet away from the screen. The change in picture quality is not gradual, but instantaneous. The only way to correct the reception is to toggle the Power switch. It works every time, but turning the console off every 15-20 minutes is not an elegant solution.

[+thegoldenband]

From memory, this is a known problem with a certain "chiclet" capacitor. Here's one thread about it. I have a VCS with this issue, and hope to fix it at some point.

[AtariBrian]

not sure, but i have an atari that is fine but when you press down the reset or select it gets all staticy... just during the time you hold down any of those 2 switches?

[zylon]

From memory, this is a known problem with a certain "chiclet" capacitor. Here's one thread about it. I have a VCS with this issue, and hope to fix it at some point.

(6-switcher shown) Might want to replace the 7805 regulator as well.

[Andromeda Stardust]

not sure, but i have an atari that is fine but when you press down the reset or select it gets all staticy... just during the time you hold down any of those 2 switches?

Yes, the screen does get little sparkles on it whenever I press the the select and reset buttons. So the capacitor looks like a little green Chiclet? Is it a tantalum capacitor or a Mylar capacitor? It should be an easy fix to replace the voltage regulator and the capacitor. So according to the other thread, I need to use a .1u (microFarad) cap for the "chicklet".

SYMPTOM:

Screen becomes snowy and/or no color after several minutes of play.

Reset cures problem but only for a while.

 

REPAIR:

CX-2600 [six switch] owners, try replacing the .22 ufd capacitors,

(they look like green Chicklets) on teh upper PCB near the ON/OFF

switch (Repace with .22ufd 100 vold cap).

 

CS-2600A [four switch] owners, should replace the .1ufd capacitor,

C241 (it also looks like a green Chicklet) in the lower left hand

 

corner of the PCB. (Replace with .1ufd 24 vold cap.)

I had a feeling I wasn't the only owner with an old Atari that exhibited this problem. Somene on NintendoAge suggested checking for cold soldier joints, but there didn't seem to be much evidence of cold joints on the bottom of the board. I figured the people here would be more knowledgeable about the Atari VCS system.

 

I'm curious, will placing a torroidal RF choke on the power cable and the coax help also? Currently, the picture is clean enough as it is, at least until the "fuzzies" come back. I'll got to Radio Shack on Monday and pick up an extra cap and a 5V regulator, a desolder braid, and maybe a snap-on RF choke for the 1ft coax I placed inside I Atari. funny thing was, the other night I left my Atari on with the Ms PacMan "attract" mode/title screen, and the fuzzy symptoms never showed up, but as soon as I connected a joystick and started playing, the ugly symptoms popped up again.

[gorfcadet]

I get a fuzzy streak down just right of the middle of the screen when Ms Pac eats a fruit or a ghost monster to a lesser degree. It goes away as soon as the audio chime is over. Does not occur on any other game I have or play.

[+RichG1972]

stardust4ever

 

I had a similar problem with my Atari 2600 4 switch but rather than tear the unit apart I tried something, I bought some electrical contact cleaner from Radio Shack which is a foaming kind that dissipates as it dries and used it on the front and back of the circuitboard and inside the 4 main switches as well as the channel selector switch, and lo-and-behold the problem was solved for me. I also used the stuff on my vintage 1986 2 dial KTV and it greatly improved everything. I even cleaned the inside of my original TV/GAME switchbox thos way and moved the switch back and forth a few times and NO PROBLEM. Food for thought before you tear it apart and do something that can't be reversed. Also you might consider spraying the places on the board where your joystick ports are soldered into to clean them, they could be grounding out. I have an Atari restoration business and I restore 4 switch units to stock I have a thread on here of one of my restorations, might wanna check it out, and you can PM me for more help and input if you like

Edited June 25, 2012 by RichG1972

[Andromeda Stardust]

Well, fact is, I had already used the contact cleaner on all of the switches and contacts, and completely replaced the RCA cable with a 1ft coax cable inside the unit. Also added a Power LED (rated 12V) to the 9V traces between the power switch and the regulator. Merely cleaning the board, switches, and electric contacts with contact cleaner didn't solve the problem.

 

I took the advice of other forum members and replaced the green "chiclet" .1uF capacitor as well as the 5V regulator as someone suggested. It seems to get an even cleaner signal to the TV than before. Radio Shack didn't appear to have RF chokes though, although they may not be necessary. I'm not even sure the guy at the store knew what I was asking about. Either way, I played Ms Pacman for 30 minutes and the "fuzzies" did not return. BTW, even though I keep mentioning seeing the messed up colors on Ms Pacman prior to repairing my console, I also got "fuzzies" while playing Video Olympics and on both Pitfall games as well. The other games, I didn't play for long enough intervals for the problem to surface. The Atari seems to be cured for the time being.

 

Thanks for the help, guys...

Edited June 25, 2012 by stardust4ever

[+RichG1972]

Well, fact is, I had already used the contact cleaner on all of the switches and contacts, and completely replaced the RCA cable with a 1ft coax cable inside the unit. Also added a Power LED (rated 12V) to the 9V traces between the power switch and the regulator. Merely cleaning the board, switches, and electric contacts with contact cleaner didn't solve the problem.

 

I took the advice of other forum members and replaced the green "chiclet" .1uF capacitor as well as the 5V regulator as someone suggested. It seems to get an even cleaner signal to the TV than before. Radio Shack didn't appear to have RF chokes though, although they may not be necessary. I'm not even sure the guy at the store knew what I was asking about. Either way, I played Ms Pacman for 30 minutes and the "fuzzies" did not return. BTW, even though I keep mentioning seeing the messed up colors on Ms Pacman prior to repairing my console, I also got "fuzzies" while playing Video Olympics and on both Pitfall games as well. The other games, I didn't play for long enough intervals for the problem to surface. The Atari seems to be cured for the time being.

 

Thanks for the help, guys...

Best Electronics offers an RF cable with the RF suppressing torrid/choke already mounted to it, I bought one back in 2003 and it works like a charm, but this is the item you are talking about if I am right:

 

http://www.radioshack.com/product/index.jsp?productId=3012599

Edited June 25, 2012 by RichG1972

[Andromeda Stardust]

Nah, no need for a special cable. I just went back to Radio Shack and bought a couple of RF chokes. Apparently, I wasn't looking in the right place. It's in the component tray under "inductors". I bought one big blocky one for the coax which I hid away inside the Atari:

http://www.radioshack.com/product/index.jsp?productId=2103222

and a 2-pak of the smaller-sized ones. I inserted the power cable through the smaller one twice so it wouldn't slide around, so now I have a spare for something else. The chokes do make a difference. The previously clear picture is now prsitine: I literally cannot see any signs of fuzz at all on any solid color areas. Also, I just got done playing Centepede for well over an hour with absolutely no problems whatsoever with fuzz in the TV signal, and I got a high score of 38764 points! It was daylight outside when I started playing; now it is nighttime...

 

Consider the problem solved. I believe what really made the difference was replacing the green "chiclet" capacitor and the 5V power regulator.

[SlowCoder]

I'm intermittently fuzzy. RT says TGA is really fuzzy.

[+RichG1972]

Nah, no need for a special cable. I just went back to Radio Shack and bought a couple of RF chokes. Apparently, I wasn't looking in the right place. It's in the component tray under "inductors". I bought one big blocky one for the coax which I hid away inside the Atari:

http://www.radioshac...oductId=2103222

and a 2-pak of the smaller-sized ones. I inserted the power cable through the smaller one twice so it wouldn't slide around, so now I have a spare for something else. The chokes do make a difference. The previously clear picture is now prsitine: I literally cannot see any signs of fuzz at all on any solid color areas. Also, I just got done playing Centepede for well over an hour with absolutely no problems whatsoever with fuzz in the TV signal, and I got a high score of 38764 points! It was daylight outside when I started playing; now it is nighttime...

 

Consider the problem solved. I believe what really made the difference was replacing the green "chiclet" capacitor and the 5V power regulator.

Ok then let me run something by YOU and maybe you can help me, my Atari has been played on several other TV's and played just fine with no flaws, now on my 1986 KTV the picture goes fuzzy until I tap the VHF dial marked 2 thru 13, then the picture clears up. I am thinking the tuning mechanism inside the TV needs to be cleaned out due to dust having built up over time. Possible? Let me hear your thoughts, as I said I already ruled it out being the Atari so it has to be the VHF tuning dial that is dirty or the manual tuning ring.

[Andromeda Stardust]

Nah, no need for a special cable. I just went back to Radio Shack and bought a couple of RF chokes. Apparently, I wasn't looking in the right place. It's in the component tray under "inductors". I bought one big blocky one for the coax which I hid away inside the Atari:

http://www.radioshac...oductId=2103222

and a 2-pak of the smaller-sized ones. I inserted the power cable through the smaller one twice so it wouldn't slide around, so now I have a spare for something else. The chokes do make a difference. The previously clear picture is now prsitine: I literally cannot see any signs of fuzz at all on any solid color areas. Also, I just got done playing Centepede for well over an hour with absolutely no problems whatsoever with fuzz in the TV signal, and I got a high score of 38764 points! It was daylight outside when I started playing; now it is nighttime...

 

Consider the problem solved. I believe what really made the difference was replacing the green "chiclet" capacitor and the 5V power regulator.

Ok then let me run something by YOU and maybe you can help me, my Atari has been played on several other TV's and played just fine with no flaws, now on my 1986 KTV the picture goes fuzzy until I tap the VHF dial marked 2 thru 13, then the picture clears up. I am thinking the tuning mechanism inside the TV needs to be cleaned out due to dust having built up over time. Possible? Let me hear your thoughts, as I said I already ruled it out being the Atari so it has to be the VHF tuning dial that is dirty or the manual tuning ring.

I haven't seen one of those TVs with the manual tuners in years... But, I think you've answered your own question. What you'll probably need to do, is remove the panel off your TV and spray contact cleaner into the tuner apparatus, then twist it back and forth a good few times to work in the solvent. It may help to bend up the prongs on the rotating contact to yield a better electrical connection, although that may also make it harder to turn the knob. Sorry, I don't know much about TV repair. I do remember my dad's old TV we got from the 80s. As a child, in the old house where I lived, my mom and dad still had a black-and-white TV, which they got rid of when they moved in 85. The new TV had channels 2-13 VHF, and 5 UHF presets. The presets had to be hand-tuned by opening up the panel and rotating a dial with a tiny screwdriver. The buttons for 2-13 could also had to be manually tuned as well. Talk about a pain in the rump...

[atari_envy]

A shout out and thanks to this and other AtariAge threads discussing this issue. I wanted to add my experience.

 

My heavy sixer would start to get a fuzzy picture after playing for a while. Recently, the picture was always fuzzy, lots of noise on the screen as if the connection was bad. I found that unplugging the 2600 would reset the picture, but it would slowly go fuzzy again until unplugged. I found this thread and decided to replace the 7805 chip and the two green chicklet capacitors.

 

Radio Shack no longer carries the .22ufd 100V capacitors in their stores, but you can order online. You can still get the 7805 chips in the store, but their prices are a little high. So I ordered from http://www.jameco.com . I have used them before to order RAM chips for my stand-up Joust arcade machine. While cheap, it is important to note that they charge a $5.00 fee if your order is less than $10.00, so you have to factor that in to your pricing decision.

 

Replaced the parts with a little soldering, and the picture is nice and clear now. Below are the parts from jameco:

 

Part#786138 Description: IC,LM7805CT.,TO-220/3, 5V 1A Price .45

Part#26972 Description:CAP,MYLAR,.22uF,100V,10% Price: .29

[Andromeda Stardust]

Glad to hear you fixed your issues. I got my first Atari in 2012, a 4-switch woodgrain model, and I had issues with the fuzzy picture. I posted about the problem on NintendoAge and nobody was able to help me. Someone suggested I post about it on AtariAge, so I did. In fact, the OP is my first post here at Atariage. I now have a couple hundred more posts on AtariAge than I do at NintendoAge. Cheers and I'm glad you got your picture fixed!

[zborgerd]

A shout out and thanks to this and other AtariAge threads discussing this issue. I wanted to add my experience.

 

My heavy sixer would start to get a fuzzy picture after playing for a while. Recently, the picture was always fuzzy, lots of noise on the screen as if the connection was bad. I found that unplugging the 2600 would reset the picture, but it would slowly go fuzzy again until unplugged. I found this thread and decided to replace the 7805 chip and the two green chicklet capacitors.

 

Radio Shack no longer carries the .22ufd 100V capacitors in their stores, but you can order online. You can still get the 7805 chips in the store, but their prices are a little high. So I ordered from http://www.jameco.com . I have used them before to order RAM chips for my stand-up Joust arcade machine. While cheap, it is important to note that they charge a $5.00 fee if your order is less than $10.00, so you have to factor that in to your pricing decision.

 

Replaced the parts with a little soldering, and the picture is nice and clear now. Below are the parts from jameco:

 

Part#786138 Description: IC,LM7805CT.,TO-220/3, 5V 1A Price .45

Part#26972 Description:CAP,MYLAR,.22uF,100V,10% Price: .29

 

 

A capacitor kit is a good way to have a supply of a variety of caps if you are trying to have stuff on-hand for electronics repairs. Elenco has a 100 piece cap kit, for $10-$14 depending upon who you buy it from. http://www.amazon.com/gp/product/B004YHZDW0 . It's good if you have to add items to an Amazon order to make a super saver shipping minimum.

 

The kit has a bag containing 5 pieces of .22 uF mylar @ 5% tolerance. The electrolytics appear to be "Qunlo" brand. I cannot attest to their long-term quality, but they seem fine.. If I buy electrolytics, I normally prefer brands like Panasonic and Nichicon. I'm not too worried about ceramic chip and mylar caps though.

 

There are other kits out there as well, such as this: http://www.amazon.com/Joe-Knows-Electronics-Value-Capacitor/dp/B007SVHFXO/

[Andromeda Stardust]

Another idea, although it's kind of a hack, if Radio Shack doesn't have the .22 caps available for the old 6-switch Ataris and you need 2.2uF ASAP, they still carry the .1uF as far as I'm aware and you can always stuff two .1 "Chiclets" caps side by side in parallel (this will double the value to .2uF) for the same net effect. The 4-switch Atari models used a .1uF "Chiclet" and Radio Shack still carries those to the best of my knowledge so that is what I installed in mine.

[zborgerd]

I swapped my .22 uF caps out in my 6-switch today (in addition to a RIOT swap http://atariage.com/forums/topic/218031-6-switch-tele-games-game-select-crash/ ). The cap replacements stabilized the video when I press the "Game Select" switch. I'll probably also replace the axial electrolytics at a later date.

 

Thanks for the great info here!

[zborgerd]

I just replaced the .1 uF in my Vader as well as the 4.7 uF electrolytic in front of the RF modulator. Seems to have improved overall stability in this one as well.