Do all versions of the 2600 have poor quality PCBs?

[MaximRecoil]

 

??

 

First off, taking sandpaper to the bubbled areas, the traces are silver, not copper. If they were copper, 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 the board.

 

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

 

If you sanded down to copper on a bubble, then it is, of course, the trace itself that is bubbled up, thus lifted from the board beneath that bubble. If your traces on whatever board you are doing this on are silver in color then they are plated, most likely with tin. Again, there is no way for solder or anything else to get between a trace and already-applied solder mask. Solder mask is like paint; if you try to force something beneath it, it will just chip off. The solder mask is, of course, already applied to the bare PCB before anything gets soldered to it.

Edited October 14, 2015 by MaximRecoil

[+save2600]

Nah, it's coming back to me now… haven't etched a PCB board or developed my own film since H.S..

 

"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".

 

Traces themselves are NOT coming up, trust me... I'd bet your life on it! lol

 

Unless I'm mistaken and talking about commercial products here, you're not likely to see copper only underneath a coated board, since who knows when last. In these times, should always have a good layer of tin/solder on it.

[MaximRecoil]

Nah, it's coming back to me now… haven't etched a PCB board or developed my own film since H.S..

 

"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".

 

Traces themselves are NOT coming up, trust me... I'd bet your life on it! lol

 

Unless I'm mistaken and talking about commercial products here, you're not likely to see copper only underneath a coated board, since who knows when last. In these times, should always have a good layer of tin/solder on it.

 

Can you post a picture of the board you sanded to bare copper (closeup of the part you sanded)?

 

By the way, Nintendo arcade PCB traces are bare copper for sure:

 

 

Edit: If they used a crude method to tin the copper traces prior to applying solder mask, then it is certainly possible that the bubbles are in fact solid mounds of tin. I'm not familiar with that step because we didn't do that in the PCB factory I worked in; our traces were bare copper like the Nintendo Punch-Out board above. However, the theory of solder seeping beneath already-applied solder mask to form those mounds is 100% impossible.

Edited October 14, 2015 by MaximRecoil

[+save2600]

You can see here, the length of the ground plane is uneven, not "bubbled" per say, as evidenced by the green coating remaining. If it were simply bubbled and traces were lifted up, I'd have been able to do a much more even job of sanding as I applied pressure. Again, the entire board is coated with tin over the copper traces and it is the uneven layer of tin that is causing the appearance of bubbling. Nothing here that suggests lifting of any kind.

 

 

Re: the Nintendo board not being tinned, guess just different (or cheaper) methods of producing boards. Seems you stand a better chance of oxidation on the traces if the mask coating gets scratched or damaged. Tin/solder atop the copper more robust you'd think - which brings us back to the fact of how robust Atari gear typically is!

[MaximRecoil]

You can see here, the length of the ground plane is uneven, not "bubbled" per say, as evidenced by the green coating remaining. If it were simply bubbled and traces were lifted up, I'd have been able to do a much more even job of sanding as I applied pressure. Again, the entire board is coated with tin over the copper traces and it is the uneven layer of tin that is causing the appearance of bubbling. Nothing here that suggests lifting of any kind.

 

pcb.jpg

 

Thanks for the picture (and see the edit to my post above). Yes, those are definitely solid mounds of tin, which means they used a crude method to tin the traces before applying solder mask, a practice which evidently went out of vogue for the most part at some point in the '80s. What I would like to know is how they avoided creating short-circuit bridges between the smaller / closer-together traces while crudely tinning them.

[+save2600]

 

Thanks for the picture (and see the edit to my post above). Yes, those are definitely solid mounds of tin, which means they used a crude method to tin the traces before applying solder mask, a practice which evidently went out of vogue for the most part at some point in the '80s. What I would like to know is how they avoided creating short-circuit bridges between the smaller / closer-together traces while crudely tinning them.

 

Somebody else more knowledgeable than us has *got* to chime in on this already! lol

 

Not so sure the tinning method was as crude as you think. Probably a lot quicker and efficient than one would surmise at first blush anyway. Seem to remember a process of applying compounds, rinsing and repeating when we were taught how to make circuit boards. Could be confusing that with the process of simply etching the copper though - too damn long ago and too damned lazy to look into it right now. Besides, all this talk is cutting into my drinking time!

[MaximRecoil]

 

Somebody else more knowledgeable than us has *got* to chime in on this already! lol

 

Not so sure the tinning method was as crude as you think. Probably a lot quicker and efficient than one would surmise at first blush anyway. Seem to remember a process of applying compounds, rinsing and repeating when we were taught how to make circuit boards. Could be confusing that with the process of simply etching the copper though - too damn long ago and too damned lazy to look into it right now. Besides, all this talk is cutting into my drinking time!

 

"Crude" as in, not a perfect, thin, even application of tin like you'd find on a "tin can" (which is tin-plated steel), or tin-plated QD terminals (tin-plated copper). Even DIY tinning jobs on copper cookware don't usually have mounds of excess tin all over the surface. It seems like an unnecessary step anyway, since the only reason to tin-plate electrical conductors is for corrosion-resistance, but the traces will be covered with solder mask anyway, which seals out oxygen and moisture, preventing corrosion.

 

In any event, I have a higher opinion of the quality of Atari's boards now, though their pads are still relatively delicate.

[+save2600]

 

...but the traces will be covered with solder mask anyway, which seals out oxygen and moisture, preventing corrosion.

 

 

Until an operator or repairman stacks boards (and most all do, have and will) scratches them all up and/or stores improperly! DOH!

 

I really should inventory and move some of this stuff someday.

 

[MaximRecoil]

I could use a shelf or something for my loose arcade boards. I don't have a ton of them; about 10 or so which are not installed in a cabinet, but they are currently just leaning up against the wall with a cloth over them to keep the dust off.

[+save2600]

I could use a shelf or something for my loose arcade boards. I don't have a ton of them; about 10 or so which are not installed in a cabinet, but they are currently just leaning up against the wall with a cloth over them to keep the dust off.

 

No cloth needed. After a while, the cobwebs and crust from your vehicles exhaust provides a free alternative and the best protection available. Much better than conformal coating even!

[+DrVenkman]

 

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.

 

Getting back to the relative quality of the boards in VCS/2600 models, specifically with regard to 4-switch models, I've removed and replaced a difficulty switch on my Rev. 14 4-switch unit without a single problem. For such a "low quality" board, it was easy as can be do simply remove the solder around each prong on the switch and remove it, then install another one.

[Keatah]

Working on a VCS, and it has those "problem" traces. Without doubt, it is solder wicking under the insulation. The trace is perfectly flat.

[atari-dna]

 

Getting back to the relative quality of the boards in VCS/2600 models, specifically with regard to 4-switch models, I've removed and replaced a difficulty switch on my Rev. 14 4-switch unit without a single problem. For such a "low quality" board, it was easy as can be do simply remove the solder around each prong on the switch and remove it, then install another one.

The switches are very easy to remove, with proper flux and heat. Thus far, I've not had any difficulty removing them from 4 or 6 switch units. They're a *lot* easier to disassemble and clean when not attached to the PCB. I'd only remove them if they are obviously dirty and their functionality is poor. Otherwise, as DrVenkman says, shooting them with some CRC contact cleaner and swabbing in a drop of dielectric grease is good maintenance protocol.