Do all versions of the 2600 have poor quality PCBs?

[MaximRecoil]

My light sixer's motherboard has thin foil-like traces; so thin and poorly adhered that they bubble up everywhere. My Atari Missile Command arcade machine's motherboard is the same way. I have about a dozen other arcade motherboards from e.g., Nintendo, Technos, SNK, Capcom, Data East, and they all have good quality PCBs. The motherboards in other consoles I've opened up (e.g., NES, SNES, Genesis) all have good quality PCBs too. Oddly enough, the PCB used for my 2600's "switchboard" is actually decent; the traces appear to be thicker, and none of them are bubbling up.

 

Poor quality PCBs don't really affect reliability in and of themselves, but they are no fun to work on, because those ultra thin, poorly adhered traces and pads are so easily damaged by soldering iron heat and/or suction from a desoldering tool.

[Andromeda Stardust]

My 4-switch woody has some of the green resin flaking off, but the traces themselves seem pretty beefy. I had some minor damage to the via when I replaced the regulator and filter cap, but this was before I invested in a decent desolder gun. The eyelet separated slightly but the copper trace held so all is good. I'm kind of scared to install the set of switches I bought from Best. My select and reset still work but have a bit of sparkle and bounce in them, even after cleaning with contact cleaner. Annoying for those games which have like 80 game modes and skips across the one you want due to contact bounce.

[Opry99er]

^^Yes... I have this exact problem with my 4 switch woody!! Skips variations... Contact cleaner might work, you say?

[Papa]

This was apparently what Steve Jobs said to Mr. Bushnell when he walked right into his office.

 

1:11

 

[Mitkraft]

Wow, that is very interesting! I have to confess, I didn't realize Jobs has any connection to Atari.

[MaximRecoil]

Contact cleaner might work, you say?

 

Probably not. Each time a metal-to-metal contact switch is used, the sudden surge of electricity erodes the metal on a microscopic level. This accumulates over time. Eventually, the eroded contact surfaces can make multiple, nearly simultaneous contacts with each other when you press the switch, due to the unevenness, which the console interprets as multiple presses of the switch. This was very common in the days when arcade machines had leaf switch buttons (because arcade machines typically saw such heavy usage), and was often cured by sanding down the contact points. It can also happen with microswitches, but it usually takes longer, and there is no practical solution other than replacing the switch. It started happening with the microswitch for the left-click button in my PC mouse back in 2008, which I bought in 2001. So I replaced the microswitches in it, and as of the past couple of months, I've noticed signs that it is starting to do it again.

 

The Atari 2600 select switch is a momentary slide switch, and even though it is somewhat open, I don't think there's enough access to do any sanding. I've never checked to see if taking them apart is feasible or not.

Edited October 5, 2015 by MaximRecoil

[+DrVenkman]

VCS/2600 switches can indeed be disassembled but it's not an elegant operation. Then can be opened up, cleaned and lubed with some dielectric grease if you like, and put back together. Or you can do what I do and simply spray them with CRC and cycle them a couple dozen times while the excess cleaner drips out. Blot the outsides dry, let the internals dry for a few more minutes and they generally work fine. And if not, parts from donor systems are still pretty cheap.

[Mr SQL]

 

Probably not. Each time a metal-to-metal contact switch is used, the sudden surge of electricity erodes the metal on a microscopic level. This accumulates over time. Eventually, the eroded contact surfaces can make multiple, nearly simultaneous contacts with each other when you press the switch, due to the unevenness, which the console interprets as multiple presses of the switch. This was very common in the days when arcade machines had leaf switch buttons (because arcade machines typically saw such heavy usage), and was often cured by sanding down the contact points. It can also happen with microswitches, but it usually takes longer, and there is no practical solution other than replacing the switch. It started happening with the microswitch for the left-click button in my PC mouse back in 2008, which I bought in 2001. So I replaced the microswitches in it, and as of the past couple of months, I've noticed signs that it is starting to do it again.

 

The Atari 2600 select switch is a momentary slide switch, and even though it is somewhat open, I don't think there's enough access to do any sanding. I've never checked to see if taking them apart is feasible or not.

Excellent description; an alternative solution to this problem is to pull up hard on the switch while throwing it a couple dozen times and push down hard and repeat - the parts sand each other down.

[MaximRecoil]

I'm kind of scared to install the set of switches I bought from Best. My select and reset still work but have a bit of sparkle and bounce in them, even after cleaning with contact cleaner. Annoying for those games which have like 80 game modes and skips across the one you want due to contact bounce.

 

I just installed a set of 6 new switches from Best Electronics, in my heavy sixer, and it was a breeze. One shot on each leg's solder joint with a Soldapullt DS017 and the switches just fell out (and the pads withstood the heavy suction of the industrial strength DS017 just fine; it is the same model we usually used in the PCB factory I used to work at). In the case of the sixers, the switchboard is a better quality PCB than the motherboard, so I expected it would go smoothly anyway.

 

As for the 4-switch models like yours, the switches are on the low quality PCB used for the motherboard, so I don't know if it would go as well. Lighter suction such as from a typical desoldering gun would be a good precaution, though I don't know how well a typical desoldering gun would handle those relatively large solder joints. I haven't used a desoldering gun much. We had Metcal desoldering guns hooked to shop air at the PCB factory, but I rarely used them, because we made high quality PCBs (they went into elaborate industrial fire alarm systems, which were categorized as "life saving equipment", so they had to be high quality) and the components we usually had to desolder had good breathing room between their legs and the pads, so the Soldapullt worked perfectly fine, and was more convenient.

 

By the way, I put a coat of car wax on all of the brushed aluminum knobs of the new switches. Hopefully this will prevent them from oxidizing/corroding like the originals did.

Edited October 14, 2015 by MaximRecoil

[Keatah]

My light sixer's motherboard has thin foil-like traces; so thin and poorly adhered that they bubble up everywhere.

 

Are the traces actually bubbled? Or is that solder flowing along them and getting trapped between the green insulation coating and the trace?

[MaximRecoil]

 

Are the traces actually bubbled? Or is that solder flowing along them and getting trapped between the green insulation coating and the trace?

 

The traces are actually bubbled up. Solder is only on the pads, so it doesn't have anything to do with it. Also, the separation is between the traces and the fiberglass board, not between the traces and the solder mask (green insulation coating). All of my Atari main PCBs (6 2600s, 1 7800, 1 Missile Command arcade PCB) have bubbled-up traces, some worse than others.

 

You can see plenty of bubbling traces in this picture of the solder side of a 2600 six-switch motherboard (not mine).

[+save2600]

By "poor" quality, do you mean to ask why most of these electronic game systems that have gotten used and abused over the last 38 years still work? Then yes, they are of the upmost poorest of quality PCB's ever made. And how!

[+save2600]

On a serious note, the bubbling you see are not the traces being pulled up themselves. Just the uber thin green coating on the board over the trace. Quite common to see in PCB's of the time and even into the arcade and pinball games of the era and well into the 90's.

[Keatah]

Nope. That's solder wicking. Solder flows along the trace and looks like bubbles..

Edited October 14, 2015 by Keatah

[+save2600]

Always thought of solder wicking as when the solder climbs up on a lead of a component (not actually under the coating following a trace). OR if you use a wick to de-solder something.

 

Are you saying you think that solder is getting between the coating and the trace and that's what's causes the bubbles? Not always the case because if you press down on the coating, you'll see it give or just flake right off.

 

I think it has more to do with too much heat being applied and/or the coating not making that great a seal and moisture/air/oxidation getting the better of it over time.

[Keatah]

I've seen them three ways, air bubbles, heat crinkling, and solder flow creeping along the trace.

 

UPDATE: Sorry I had to check something and didn't know when I'd be back. Wicking is a relative term. Solder tends to flow to where there is no solder. Just like a drop of water on paper. Desoldering wick is "dry" to a solder-rich connection and the solder will flow to the wick until it is equally spread among the copper fibers and the trace you're working on. And that is why you can't really "wick-off" 100% of the solder. A thin coating always remains behind. Maybe you can use 10 inches of braid and some abrasion. But I never bothered to go that far.

 

You can test to see if the trace itself is bubbled or the resist mask is crinkled or if there is solder flow.

 

Just use a safety pin. Scrape away a little bit and try pushing the pin down. What happens?

 

1- Light resistance and the ability to easily peel away a thin strip = air bubble

2- Ability to push the trace flat and have it stay = warped trace

3- Hard resistance to pushing the pin, leaves a crater mark = solder wicking & creep.

 

Additionally, if the trace is bubbled and has significantly different shades of green on the bubble - then you'd have corrosion because the two layers separate and cause different light reflectivity.

 

You may also test with a soldering iron and wick. Or desoldering gun. The insulation won't really go flat again by itself, but you'll see it crinkle and develop dark streaks as flux surface tension pinches it up and pulls it down. Much like picking up a wet baggie, you get some crease lines propped up by a minuscule amount of water and surface tension preventing the material from laying perfectly flat against itself.

 

The VCS board in the pic strongly looks like solder wicking. You'll also note it's more pronounced at the via and tapers off as it progresses along most traces. Had the board been in the wave machine longer, it would creep more. Larger areas are more prone to this, smaller traces provide for less expansion of the masking and therefore little or no solder flows under it.

 

I have an Apple II mainboard that was built with similar chemistry and it has the solder wicking "issue". Which really isn't an issue at all. In fact, those traces are now thicker and beefier in those areas!

Edited October 14, 2015 by Keatah

[+save2600]

So I guess the question remains as to why you saw that so much in the 70's-90's. Manufacturing technique to be blamed on the soldering job (heat or length of time applied) or the composition of the coating? Either way, it's typically harmless. More of a cosmetic issue than anything serious.

[MaximRecoil]

By "poor" quality, do you mean to ask why most of these electronic game systems that have gotten used and abused over the last 38 years still work? Then yes, they are of the upmost poorest of quality PCB's ever made. And how!

 

As I said in my OP:

 

"Poor quality PCBs don't really affect reliability in and of themselves ..."

 

On a serious note, the bubbling you see are not the traces being pulled up themselves. Just the uber thin green coating on the board over the trace. Quite common to see in PCB's of the time and even into the arcade and pinball games of the era and well into the 90's.

 

No, the traces are bubbled up, i.e., separated from the fiberglass board. Look at the picture I linked to. If you think solder mask can take on such an appearance, then I don't know what to tell you. Also, solder mask is applied to the entire board (except for the pads of course); if it could assume such bubbling formations, the bubbling would not be perfectly restricted to the trace areas. On top of that, you wouldn't see the same color on the bubbled areas as on the non-bubbled areas if it was somehow the solder mask which was bubbling up. The color of the trace areas is a specific result of the color of copper as viewed through a thin, translucent coating of solder mask adhered to it. If the solder mask could somehow bubble up while the traces remain flat, the color would be different.

 

And it isn't particularly common. None of my non-Atari console and arcade PCBs from the '80s and '90s have even any hints of bubbled up traces. I have seen it on non-Atari arcade PCBs, usually from the '70s, but none that I own (I own non-Atari arcade PCBs from Technos, Nintendo, SNK, Data East, and Capcom).

Edited October 14, 2015 by MaximRecoil

[MaximRecoil]

Nope. That's solder wicking. Solder flows along the trace and looks like bubbles..

 

No. There is no solder on the traces. That's what solder mask is for; to keep solder off the traces.

[+save2600]

Okay, since I have the time - thought I'd look at some of the boards I've got laying around. What I found was that one Nintendo and one Konami board from the 80's had zero bubbling. But you're right, nearly all of the Atari, Bally, Stern, Data East and Williams boards do! With one exception... Bally lamp driver board that's beige, so probably indicates an early production/prototype run.

 

But NONE of the boards with the bubbling have traces that are lifting up or are separated from the board itself. Only time I remember seeing that is when someone had clumsily used the wrong tool (gun instead of iron) or used a temperature or tip that was too hot for the job. That's when you usually see the pads becoming separated from the board and now you've got a huge mess that has you running jumper leads between components. lol

 

Of all the switches I've replaced on Atari systems throughout the years, can't remember that happening to me personally but I have accidentally lifted traces/pads while being impatient de-soldering I.C.'s. Before you learned to clip the legs and pull out the remains one by one as you heat 'em up that is.

 

 

 

 

 

[Keatah]

The solder creeps under the resist and wicks and flows its way along the copper trace, displacing the mask as it makes its way along fresh copper. That's the situation in that 2600 pic.

 

It happens at the point where the resist edge ends. At the microscopic level, the flux causes a lot of activity there, and the resist flaps like a flag in the wind encouraging solder and flux to flow along the trace.

 

Go ahead and try to compress that area. You won't do it without significant force, whatever force is needed to compress and cause room temp solder ridges and bumps to flow and move out of the way.

 

A displaced or warped trace will flatten somewhat easily. Yup, all that thin copper with air & space under it. A flat-blade screwdriver works nicely here. Use the tip if you have to. Not the case here either. QC would never let something like that slide by.

 

If it's air bubbles, and the trace is bonded to the board still, the coating will flatten with the touch of a q-tip, or flake off with a toothpick. That is not the case with that 2600.

[+save2600]

^ You're right Keatah, does seem to be solder under the masking on those parts. Traces intact and firmly attached to the board underneath though.

[R.Cade]

I've seen quite a few Commodore 64 boards like that also- specifically the 1983 models. I think the boards were all made in Taiwan back then, so maybe it was a specific fab or process that shows that symptom. I have not noticed higher failure rates in those boards.

[MaximRecoil]

But NONE of the boards with the bubbling have traces that are lifting up or are separated from the board itself.

 

All of those boards with bubbling are cases of the trace lifting/separating from the board itself. It isn't possible for a trace to both be bubbled up and still attached to the board, unless the board managed to bubble up with it. As for it just being solder mask, like I said, it would have a completely different appearance if it were just bubbled up solder mask. You can look at the color and see that it is bubbled up copper. Also, press on the bubbles with your finger. If the bubbles were made of solder mask (which is very thin and has very little potential to form structures), they would easily break if you pushed on them. You'll find that those bubbles are quite structurally sound, because they are made of copper sheet.

 

The solder creeps under the resist and wicks and flows its way along the copper trace, displacing the mask as it makes its way along fresh copper. That's the situation in that 2600 pic.

 

That absolutely does not happen. For starters, solder mounds coated with solder mask would be a different color than copper traces coated with the same solder mask, so that disproves your theory right there. Secondly, do you realize what kind of a mess you'd have if solder could get under the solder mask and onto the traces? You'd have short circuits everywhere, because all of the small, tightly spaced ones would be bridged with solder. These are wave soldered; which means they pass over a "sea" of molten solder. In order for this to work, you have to have solder mask covering the traces, and it has to be 100% effective.

 

 

 

It happens at the point where the resist edge ends. At the microscopic level, the flux causes a lot of activity there, and the resist flaps like a flag in the wind encouraging solder and flux to flow along the trace.

 

Your idea that big mounds of solder can make their way throughout the trace network by seeping beneath solder mask is 100% false. Not only does it not work that way, but solder mask isn't like a cloth sheet which can simply conform to the shape of something slid under it. If you force something under it, it will simply chip away. It is like paint. Think of paint on a car. You can dent the body to a certain point and the paint will remain adhered to it, but you can't slide something between the paint and the steel and have the paint conform to said something.

 

 

 

Go ahead and try to compress that area. You won't do it without significant force, whatever force is needed to compress and cause room temp solder ridges and bumps to flow and move out of the way.

 

A displaced or warped trace will flatten somewhat easily. Yup, all that thin copper with air & space under it. A flat-blade screwdriver works nicely here. Use the tip if you have to. Not the case here either. QC would never let something like that slide by.

 

It doesn't compress easily because the bubbles are dome structures formed in copper sheet, with the dome structures being supported all around their bases.

 

 

 

If it's air bubbles, and the trace is bonded to the board still, the coating will flatten with the touch of a q-tip, or flake off with a toothpick. That is not the case with that 2600.

 

Yeah, it's not a case of air bubbles in the solder mask. You can simply look at it and see that the bubbles are the same solder-mask-painted copper color as the rest of the traces.

 

^ You're right Keatah, does seem to be solder under the masking on those parts. Traces intact and firmly attached to the board underneath though.

 

Impossible (see above). Also, please explain how solder coated with solder mask could have the exact same color as copper traces coated with solder mask. There is no interruption/change in color at the transitions from flat traces to bubbled traces. Solder is silver, copper is not.

 

The traces most likely got bubbled due to heat distortion in the wave, along with not having a strong enough adhesive attaching them to the board.

Edited October 14, 2015 by MaximRecoil

[+save2600]

 

All of those boards with bubbling are cases of the trace lifting/separating from the board itself.

 

??

 

First off, taking sandpaper to the bubbled areas, the traces are silver, not copper. If they were copper colored, would be obvious there was no solder on them.

 

I continued to sandpaper them until I *finally* saw copper, then using an X-acto knife, tried lifting the trace at the very most edge where you'd *think* it could be lifted - and it could not. Not even close to looking as if the copper would come up as it was totally flush against and firmly attached to the board.

 

Sorry, but I still see NO evidence of traces being lifted anywhere on these boards.

 

I think we're forgetting how these boards were manufactured in the first place. Etched copper traces, followed by tin/solder along said traces... and it's probably in the uneven heating/cooling or distribution of tin applied to the copper, that we see the bubbling... would also explain why we sometimes see a snake-like pattern in the thinner traces.