Is single layer PCB really worse reliability than double layer

Bitrex was complaining about the adhesive failing causing pad lift due to excessive soldering iron heat during repair/rework. You'll have to ask him for his horror-stories :)

piglet

Because not all parts were completely flush with the board, allowing for pressure points which lead to cracks. You only need a tiny amount of float above the PCB to allow enough movement to crack the solder.

Pin connections were the bigger weak link as they could move slightly due to the wire connections tugging slightly (thermal expansion/contraction, gravity, vibration,...) or pressure applied to plug/unplug the connectors would lead to cracked solder mounds.

John:-#)#

Did rivets (eyelets) help? I saw them in some radios and things.

I've seen parts held down with various hardware and those connections were then usually fine.

If the device is free standing and has much mass (think 2 - 5 Watt (+) resistor or TO220 package, then you get problems over time.

John :-#)#

Oh I didn't mean rivets holding down parts. I meant in vias on single-sided boards, as a kind of solid thru-plating. They used them mostly where wires, rather than parts, were soldered through a hole.

Also, modern power supplies are often single sided and seem to have more problems from bad caps.

That was somewhat rare. Old small linear power supplies sometimes used that idea and had trouble with bad solder connections to the hollow eyelets - these were used mostly on pass transistors on the power supply so one could take it apart for service. We quickly learned to check for a good connection to the eyelet and the rest of the circuit...

Also one game - Computer Space (1st coin operated video game) - had an early double-sided motherboard where there were no plated through vias! So they had to put a bit of wire in each hole and solder it top and bottom. Back in the day there were a few bad solder joints and troubleshooting that was most annoying!

John :-#)#

John Robertson wrote in news:sP-dncfOSfd9a0vBnZ2dnUU7-L snipped-for-privacy@giganews.com:

You must have decided that on pinmame.

Because MAME is absofukenlutley 100% EXACTLY the same.... the same ROMs... all of it.

I have over 155GB of MAME data, and I can even play the old laser games that had laser disc players in them. over 35k games.

MAME is absolutely the best processor emulator ever made for this class of processors and this era of the realm.

Perhaps you looked at it years ago.

I play pacman digdug asteroids space zap galaga galaxian Tempest donkey kong popeye jack the giant killer defender burger time centipede millipede joust bosconian battlezone crazy climber frogger pole position robotron rally x qix omega race star castle ms pacman space invaders

All exactly original, and as a bonus, I can even pump my LED display with it and play on a bigger screen than ever! With a proper set up, the emulation is perfect, so exact timing on exact code = exact same gameplay experience.

So, you must be only really talking about the pinball emulator, which cannot provide the same experience the way computer based games do.

"Tom Del Rosso" wrote in news:qb7ffi$h8a$ snipped-for-privacy@dont-email.me:

Early PTH technology had elements called "annular rings". (they still do). These are pre and post PTH. The through hole inner wall plating connects between two annular rings on top of and on the bottom side of the board. Early boards had connection integrity issues and the number of VIAs was a critical thing to keep as low as possible as early failure modes were many times associated with a PTH continuity failure.

I am so glad that we have come so far since then.

Nobody counts vias any more. Multi-layer PCB circuit cards are of very high integrity these days, even on the cheap quick turn jobs.

It really is amazing how quick a 2 or 4 layer board can show up ten parts at yer door in a few days for a few hundred bucks! Wow!

John Robertson wrote in news:sP-dncfOSfd9a0vBnZ2dnUU7-L snipped-for-privacy@giganews.com:

No need for any of the arcade variety. A micro atx pc running windows or linux and an LED display in an old upright cabinet will precisely emulate any of thousands of games.

So all I have to do to be legit is own an old dead mobo, such as the mobos you have (not saying they are dead), and I then have a right to use that ROM code in my machine (no need for the entire old board).

MAME emulates everything from back then from an Altair to a Heathkit to a pocket calculator.

I DL'd gigabytes of arcade game operator's manuals. I DL'd GB of original sales posters for most of the games. Pics of the PCBs. Pics of the cabinets and artwork.

I have all of it. You likely could not name an old arcade game from then (the popular ones)that I could not start up and play.

Your game you mentioned was actually what ended up being bought by Atari and released as "Pong". I lke sorting my list by year and looking at all the old computers that came out year after year then and how laughably slow they are by my jaded eyes now.

Like all of the Indy and Iris and Indeo from SGI boxes. A bunch of HP machines... It is really fun to flip through the years looking at how bad the vga displays were. And the polymers we used then... wow.

On May 11, 2019, John Robertson wrote (in article):

I had that problem with the eyelets in Keystone battery holders - a little ooze from the battery terminal would get between rivet and solder tab terminal, and the corrosion would make the connection unreliable, The solution was to pre-tin the rivet and tab before installation:

Using a toothpick, put a very small drop of tinner's (liquid acid used for tinning steel) flux at the junction between rivet and tab. Solder rivet to tab. Wash entire battery holder in hot water to remove the acid flux residue. When dry, install and connect, using only radio solder.

I have not tried this, but I suspect that a dab of plumbers grease flux will also work, and may not require the hot wash. (Back in the day, before I knew better, I assembled a Heathkit VTVM using plumbers flux. Likewise, a signal generator. I still have them, and they still work, decades later.)

War story: In the 1970s, I knew a geology postgrad who worked as a materials engineer at a company that was building something for the US space program. They were trying to solder a copper cooling tube coil wrapped around a round cadmium-plated copper assembly of some kind, and the cadmium plating was not taking the solder. They tried all manner of fancy kinds of flux, to no avail. When I heard this story, I was amazed, because I had been soldering test leads to cadmium-plated steel Mueller alligator clips since high school. The key was to polish the cadmium-plated metal with a fiberglass brush, and use plumbers flux to pre-tin the steel. The test lead was also pre-tinned with radio solder. The lead was soldered to tinned alligator clip with radio solder. She took this story to work, and they succeeded that same day using plumbers flux from the hardware store across the street.

Joe Gwinn