Apply solder to the coil tab.

Tin the end of wire with solder.

With wire in one hand hold it against the solder tab.

With soldering iron in other hand apply heat to both wire and tab at the same time.

The trick is to tin both parts before you try and join them together

Tinning the parts is definitely Soldering 101.

I also will use a hemostat to hold things together.

I often wish I had 3 hands for soldering.

A quality soldered joint is much more reliable and resistant to vibration than a crimped connector.

Practice, practice, practice.

RussM

There's a lot of video tutorials on soldering on YouTube too. Sometimes I find it's easier by watching someone do it.

I usually hold and feed the solder with the hand I'm using to hold the loose object in place. The guy who taught me eons ago got me into the habit of wrapping some solder around my fingers and having about a 4-6 inch piece sticking out. Just point and push.

Maybe I am missing something here, but what does the picture show exactly that means the coil needs to be replaced?

Looks like the windings are cut/broke. If you look closely you will see it coming out the coil.

Here is great advice. As you reach for the soldering gun do not glance up at the TV. I did this last Sunday, Ouch! and a LOL LOL.

Simple.
Connectors are the bane of most every pinball machine. The more connectors you eliminate - the more reliable the machine. The more connectors you add -- the less reliable the machine.

Adding inline connectors to connect to coils just adds one more layer of future problems.

^^^^^ What he said ^^^^^^

Lessons learned.

Because soldering is so much easier than connectors.

I've been using and prefer quick disconnects on coils and some switches. I started doing so after I noticed my NGG was factory built this way (many coils at least).

It makes maintenance easier and a *good* mechanical connection is as good or better than a solder joint in those applications. I've had zero issues in home use.

I save soldering for board work or for coils and switches that don't have clean solder free lugs.

PS I've had plenty of solder joints break off on their own accord before--they are susceptible to vibration and pulling forces if the wire is thin enough or there isn't a good mechanical joint under the solder joint.

Just FYI Atari used connectors on coils super easy if working on. Never had a problem with a coil. Hmmm switches as well not sure but yes maybe.

I'm sure this works fine and it most likely won't lead to problems, but it is terrible technique and will lead to voids and cold solder joint. Use a solder sucker to prep the coil by clearing the hole in the lug. Then strip the wire, stick it through the hole and bend it over to hold it in place. That way you hold the solder in one hand and the iron in the other. Never hold anything in hand that is being soldered when you can easily do it the right way and make a mechanical connection before you solder.

I like soldering mechanical connections on, but I'm paranoid like that.

Connectors are ok as long as the person making the connectors knows what they are doing. Part of knowing what you are doing is not putting them on GI lights or any constantly powered circuit. Connectors on coils are just fine unless installed by a novice.

Why not just fix the break? Scrape or burn off the outer coating on the two ends of the coil wire, twist them together, and apply some solder. Then tape the repair around the coil so it won' t short with anything.

that diode looks like it's missing the middle black part, probably an optical illusion from the camera...

NYP, you're correct. I don't see a coil sleeve running out of the bracket either

just cut the winding loose, stretch over to the lug, cut off excess a strip and solder to the lug.
the solenoid will work just fine with 1 -2 windings shorter...Done.

My rule as well. Get it to hold by friction, hooked wire, twisting, braiding, or some other mechanical means first, then heat the whole connection all at once, then apply the solder and let it flow into all parts.

I would just replace it and be done with it.

I would get a manufacture doing connections with push on connectors just to speed up the assembly line and avoid needing skilled workers who can solder (and the associate health concerns of having a worker soldering all day). But to use push on connectors in a home environment to make it easier to replace a coil or switch just seem like a solution to a problem that does not exist. Most of the coils and switches in my 30+ year old games are original. They just don't go bad that often.

It takes me more time to open the game up and pull out the necessary tools/replacement parts than to do the actual solder joint.

It makes it easier to remove entire assemblies.

yeah a lot of guys on here like all of that more than playing.

Because of all the vibration. That's why your coil lugs are positioned opposite of the coil stop from the factory. To keep the vibration as far away from the connections as possible. You won't find much more severe duty for electronics than you will on a pinball machine. High voltage coils firing regularly all up and down the playfield and a heavy steel ball flying around. Typical modern games have 30 or more coils. Quick connects would never last on location. You could probably switch over at home, but I wouldn't do it. A soldered joint will always conduct better than a quick connect. I want all the power I can get.

An even worse environment for electronics is salt water boating. Even more vibration, plus salt water and salty air. There, crimp connectors followed by much shrink tubing (to waterproof) is recommended. Of course you don't see a lot of high voltage coils on small boats. Mostly radios and GPS/ fishfinders.

^^^

yet chime boxes are almost always connected with quick connects, and there would be very few places on a pinball machine that experience more use and vibration... and virtually every machine with a chime box lived a great majority of the time on location...

so that dog don't hunt...

Pretty sure my entire RFM was crimp connectors form the factory, granted I cut them all off and soldered wires back to lugs when I did the restoration as many were fouled and burnt (I assume from improper connections leading to added carbon?).

Williams factory installed quick disconnects on coils in NGG (in mine at least). Properly installed (right size) quick disconnects aren't going to vibrate off.

Power transfer also won't be an issue with the correct connector (mechanical connections are used in many high power transfer scenarios). Scenarios where you may care are high frequency scenarios where signal *quality* (not power transfer) is very important (such as the internals of radios, some computers, etc).

I also believe the lugs are positioned the way the are to prevent shorts and/or wires from getting in the way. Regardless, the vibrations will likely be fairly similar in either orientation.

I feel like its NEVER a good Soldering job UNLESS I burn myself at least once in the process....

Chime coils are different from the rest of the coils in a game. Their lugs are horizontal, not facing down like a flipper coil. The chime bars are relatively far away from their coil and essentially have shock absorbers (rubber rings) built in to dampen the vibration. Flipper coils get way more abuse. No shock absorbers and very little separation from the vibration. If you think it would work, give it a try and let us know how it works out. After 5k games or so, I imagine having to retighten connectors would be a regular deal.

I know they make some awesome quick connects today that probably would last. Way better than Radio Shack cheapies. At that point, they'd likely become too expensive. Another consideration is that coils rarely break. How many broken coils have you replaced lately? Now that EOS switches are low power, we rarely need to touch coils other than to remove them (wires still attached) for a flipper rebuild. No need to build serviceability into something that rarely needs service.

OP. The first coil you solder is a total biotch. The second isn't much better. The fifth time you do it, you have the hang of it. The 20th one you do isn't worth blinking at. And so on.

All you have to do is do it a bit and it gets much easier. Take a burned coil and some wire, and just practice on them. Once you are a bit more comfortable, attack the real one.

It is always better to solder a wire connection that does not depend on the solder for the mechanical strength of the connection. Solder is a weak structure that can become more brittle with age.

Using locking pliers to hold the wires is also a bad practice because it acts as a heat sync, making it more likely to get a cold solder joint or overheat the terminal trying to get the wire hot enough.

It is always better to remove all old solder, strip the wire back, make a good sound mechanical connection without solder, then flow the solder to the wire/tab all at once to keep your knot from coming loose during years of vibration. It's easy when you do it this way because you don't have to worry about holding the wires in place, and so much more reliable in the long run.

In addition, most solder has a rosin flux core to clean the connection (this is essential in forming a good solder joint).

Notice when you first add solder to the joint or wire, you hear a sizzling sound and get a puff of smoke that smells like pine sap (because it is pine sap). That's the rosin flux cleaning the joint as it burns off. It's a one shot deal.

When you just pre-tin the wires or terminals all the flux burns off, so if you heat them together without adding more solder (and thus flux) you will almost certainly get some kind of cold solder joint.

A good solder joint should be shiny like a little less vibrant chrome. If you apply heat for too long or decide to go back and reheat the joint, you will get a cold solder joint (it will look dull grey) unless you apply more flux, either by adding solder or just some flux by itself (flux can be purchased in a liquid pen or other forms).

If you want to see the difference between a good solder joint and a bad one, experiment by making some fresh connections and making some connections by just resoldering them (no new solder added). To really see the difference you will need to clean the flux residue off the connections by using isopropyl alcohol on a cotton swab or cleaning brush. Note that they make non-rosin chemical type fluxes these days that are easier to clean and that do not leave a sticky residue. I don't think they are quite as effective but they have their advantages. DO NOT USE any acid core solder or acid flux (plumbers use this type) as it can corrode electronic circuits.

As others have said, a good mechanical connection before soldering is best, but sometimes (as with micro-switches) it's very difficult to get the wire through the tiny hole in the terminal. If the joint doesn't get a lot of vibration, you can pre-tin the wire and terminal then add some rosin flux (it only takes a tiny bit) as previously mentioned to the wire and terminal before soldering.

Buy and assemble a bunch of these types of kits, and before you know it, you can't wait to bust out the soldering iron on a pinball machine.

http://www.radioshack.com/product/index.jsp?productId=12483547&locale=en_US

I love Atari. Nolan Bushnell was a genius. That said, Atari is not a company I would look to for pinball construction best practices. To my knowledge, they only ever made 7 commercially available pinball titles with little known production counts. Potentially maybe 2000 machines ever made by Atari. That's an average run for a single Williams title.

The coil wire has a thin paint-like insulation that you really should have removed with fine sandpaper before soldering...

Well Ok then I will point out that Automotive connectors are all crimps and not soldered and they get a hell of a lot more vibration than a pin ever will. They don't usually fail. That was kind of what i was eluding to.

There were other issues with Atari that made them not stay in long I am sure. I bet if a standard size machine and a HIT title things may have been different. At the time they were probably just testing the waters, hell Atari 800 and the rest were likely much higher profit makers. I have seen lots and lots of Atari pinball sold on ebay over the years, and many local. So numbers if not known may be much more than you think. And Hercules was just like TNT throwing machines off the roof, something that people remember (good or bad) just damn smart.

if a guy is new at soldering or is having trouble attaching wires to a coil lug, he could crimp spade connectors to the wires, push them on the lug then solder the connector to the lug.

something else i wanted to add, those automotive spade connectors you buy in blister packs at radio shack or HD are usually aluminum and really weak. i fix most of my restaurant equipment and only use stainless steel crimp on connectors. little more money ( maybe 2x but they are still cheap) they are hard as heck and have a high heat rating.
they are the only connectors that take the abuse of 240v 24-7 on my soup well warmer elements , i usually get about 2 years out of one before they fail , and my staff beat the marbles out of these.

Yup... that's the same crimp lug that just failed on my furnace - part of the remote air flow sensor. No vibration at it's location, barely any current load - but failed due to high resistance between lug and terminal. Unplugged it, replugged it and things started working again. They were good AMP lugs and not some chinese cheapies but the connection still went bad.
As I said above -- adding new connections in line or anywhere else just adds unreliability and future failures.

Lug.jpg

I hope you have a coil sleeve in there and just took it out from the pic. Coil sleeve is a must.