2. Clean parts
Once all plastic and metal parts are removed from the playfield it's time to clean them. Whilst removing everything from the playfield, I separate plastic from metal parts. All plastic parts go together. Small metal parts (screws, nuts, ..) go in the little drawers so I can assemble the game back together (unless they're really dirty, then I put them together so I can clean them with my tumbler). Larger metal parts (too large for the tumbler) like ball guides or ramps also go together in a box so I can clean them by hand.
Now I have a tumbler, I usually check which parts are dirty and need to be cleaned that way. Then I can clean them all at once and don't have to put much time or manual labor in it. But it makes assembly a bit more difficult as I have to search for the correct part each time, so you don't always save a lot of time in the end. It just depends usually. A dirty game and a lot of the same parts: everything together in the tumbler. Clean metal parts, a lot of different parts: separate parts and manual cleaning.
Ramps I clean in the dishwasher (you can put all regular plastics in there too).
You don't have to remove switches or decals. It works excellent (especially on dirty ramps).
Depending on the model, it can be dangerous ! Some models have a dry-cycle and that heat is too hot and can melt plastics ! Or plastics can fall down on the bottom of the machine which becomes too hot too. So double-check your machine and first test with a part you can afford to lose !
Also take care if some plastics have been repaired. Especially if you want to flame-polish ramps you need to make sure they are sparkling clean.
I clean flat plastics (and ramps too large for the dishwasher) by hand. Usually I do it like I wash the dishes. If parts are really dirty then I wash them two times, and rinse with a lot of clean water. Just be careful if you rub with a sponge as it's easy to make scratches. Sometimes I also clean plastics with a special cleaning product (Powerhouse), but that's only if they are really dirty.
Scratches in plastic parts and ramps can be removed or made less visible using a plastic polish or scratch remover. Novus 2 works fine, or visit a good car parts shop, they should have a product for it.
Finally, plastic ramps can be flamepolished. This really can make a huge difference to make a game look as new. But it's dangerous to do !
Some people even wax their ramps with a special show-car wax, which gives them an ultimate 'wet' look.
Large metal parts (long ball guides, ramps) which are too large for a tumbler I clean by hand. Fine steel wool is the best. Only if metal parts are really dirty or greasy I will also use a chemical product. In the past I used chrome polish or Powerhouse, now I use HG Staalpolish. This product is excellent on steel ramps ! You can also clean them with i.e. Novus 3 and steel wool. Local shops will probably also have similar products that are suited to clean stainless steel. Just choose something available and what you like.
The flaps (like at the entrance of ramps) that are made from spring steel are sometimes rusted. These can be blued again.
Gun-shops sell a product to do this.
If the flaps are bent up then you have to careful bend them a bit down again now the ramp is removed from the playfield. Ramp entries which are not fit tight onto the playfield make it harder to make the ramp shot, the pinball will loose a lot of energy going over the bump, or its path can be diverted.
Broken plastics can be repaired or replaced using different methods.
You can recreate flat plastics. Find a good scan of the plastic (check www.ballsofsteel.net), print it on self-adhesive clear film, and glue that on a plastic. Cut the plastic in shape and you're done..
But first check with pinball dealers that the plastics you need are not available as new. For very old games you may be out of luck. But for most popular recent games new plastics are available. And even for some older games you may be lucky, I was i.e. able to find NOS plastic sets for my Gottlieb Q*Bert's Quest and Black Hole games.
Warped plastics can be flattened again.
Put them between 2 pieces of heat-resistant glass and heat with a hairdryer (on the side which does not have paint on it !). Let this cool long enough between the glass. The weight of the glass will flatten the plastics.
There are other methods, some people don't put it between two sheets but just heat the plastic directly with a hair dryer. Some people even put plastics into an oven, some between glass, others don't, but using an oven is a very dangerous process ! (you need to look at it the whole time and immediately take the plastics out when they start to flatten). A hair dryer will also do the trick and is much safer, so that's the preferred method.
Here the same remark as cleaning plastics with a dishwasher: take care, get enough information, try to practice first. A lot of people have ruined their plastics because they did something wrong. After all it's usually only the heat from the light bulbs which warped them, so you don't need a lot of heat to make them flat.
Note that plastics of very old pinball machines (before 1960) should not be flattened using heat ! The only thing you can try to flatten them is to put a heavy weight on them for several days.
Repairing broken ramps is more tricky. There are several methods
and products you can use. You have to experiment with them and it also
depends on the type of damage.
Note that you will notice these repairs. So don't apply them if you want to make a game look like new. However, if you have game which is barely playable, you can fix it this way. And with a metal protector over your repair it will be invisible.
Professional plastic soldering tools exist, but these cost a lot. If you have access to them, or any other sort of heat gun or soldering tool with very precise temperature control, it's worth a try yourself. But it will be safer to contact a plastic molding company in your area and ask if they want to help you.
Some use a similar but in my opinion dangerous method (although I have not tried it myself yet). It is useable on a ramp that has a hole in it. Cut plastic from pet-bottles in the correct shape, and heat with a heat gun. The plastic will melt and both parts will become one. But as you can read in my heat-gun experiments when I was flame-polishing: heat guns are very dangerous and it's very easy to deform, or burn and permanently damage a ramp ! So try this at your own risk, and don't increase the heat in large steps or heat for too long !
Instead of soldering with heat you can use chemical products. This is something I prefer. Superglue plastic parts in place.
If a part is broken off and missing, I cut out a similar piece from a scrap ramp. It doesn't have to be a perfect fit (although the more perfect the better). Glue the edges with Superglue, and then I spray a bit of glue-hardener on it which will instantly make the superglue hard and can even fill small holes. It works great, but immediately wipe the hardener off the plastic because it can create a haze.
2-components translucent epoxy can also be used instead of glue, but as it has a much longer dry-time it is not so good to use. With superglue and an bottle of activator you can fit the parts until you they're in exact the correct position, quickly spray the activator on it and it's hard. Repair done. Using slow-curing glue or epoxy you have to make sure all parts stay in the correct position the whole time, you glue is not too thick so it leaks, and so on.
When you clean or replace plastic parts or ramps, you'll notice that some of them are held together using rivets. Removing a rivet isn't very hard but you have to know how. Either use a Dremel to grind the edges off, or use a drill. Using a drill is not advised when you want to reuse the plastic parts, as the rivet can start to spin around and melt the edges of the plastic. A short tutorial about removing rivets can be found at this site.
3. Bottom side of the playfield
Once all parts on top of the playfield are removed, it's time to start at the bottom side.
Although usually there is no strict distinction between working on the top and bottom side of the playfield - because to remove some parts on top you may have to work on the bottom side already. But some people don't go further than cleaning only the top side of a playfield, therefor I pay special attention to the bottom side too.
It's safest not to desolder anything (except for pop bumper light sockets).
At least then you can't make mistakes when soldering items back.
Switches and targets that stick through the playfield I just unscrew and let them hang loose (see picture).
But be sure not to switch the machine on anymore then because a loose part can create a short ! It's even better to unplug the machine when you start to shop it btw.
If you do have to unsolder wires from switches or coils then be sure to label every wire ! And take detailed notes, which coil has which colored wire to which lug. Pictures may be less helpful as on some digital cameras the flash may change or hide the color of a wire. Just write everything down.
Assemblies with solenoids on them are more difficult. Sometimes they have a connector
so you can remove them completely from the playfield (again: label every connector you unplug).
If they do not have connectors, then it's something you have to decide yourself.
Just unscrew a whole assembly from the playfield and let it hang loose ?
If it's too heavy this can be dangerous to do. Sometimes you have to disassemble the whole
assembly so you can remove the coil from it, so only the coil itself hangs loose
underneath the playfield. Or you only remove the assembly, clean it and immediately
put it back.
The green solenoid in the picture is still connected to the game, the assembly is being cleaned whilst the playfield is turned upside down. Note how much dirt comes out of it, a cleaning was really necessary and that plastic sleeve needs to be replaced !
You also have to decide how much you disassemble metal parts.
You can just clean the parts you can reach, or be complete and really disassemble
everything until the last part so you can clean everything on its own.
If you do the last, be sure to double-check everything if you assembled it again, as most moving parts need careful assembly. If not you may have friction which will cause the part not to operate as it should.
Take special care with parts that go up and lock in the up-position, and test them manually. I.e. ramps which move up (on Bram Stokers Dracula, Whirlwind, Pinbot, Road Kings, ..) or targets like the gofers on No Good Gofers or trolls on Medieval Madness.
Test every assembly underneath the playfield. Check for bad repair jobs,
if parts have been used which shouldn't be there.
At least make sure every part is original and works like it has to.
Manually activate each moving part on the game, see there's not too much friction.
Coils do not wear out. 50 year old coils may still work as good as the day they were new.
They should only be replaced if they are burnt, or expanded (because they were
'on' for too long and got too hot) so the plunger inside them moves difficult.
Certainly make sure that coils run dry ! No oil or other lubricant should be used, as it will only attract dirt and cause everything to block after a while. If there's oil used: disassemble, clean the plunger very well and replace coil sleeve.
Dirt will cause friction. To do a complete job you should disassemble every assembly and clean the plunger. Check moving parts also for wear and replace if necessary. Replace the coil sleeve. They are cheap, but if you are cheaper or you don't want to replace non-worn parts then at least clean them if they're dirty.
If you do not want to spend the time needed to disassemble everything, or the assemblies aren't too dirty, at least try to clean plungers as much as possible to remove dirt-buildup.
Only on the very first game I shopped I replaced all coil sleeves of every coil. Never again will I do that again. It's most of the time overkill, unless i.e. someone sprayed oil on every coil. Just make sure they're clean enough and only replace them if it's really necessary: if they're too dirty or are worn inside.
Tip: if you want to clean a whole assembly, take a look at the manual. It will have a drawing of the parts that make up each assembly used in the game. That will help you to know how to disassemble it (and where everything goes when you want to assemble it again and don't know exactly how it was). You can also see in advance if i.e. small parts, C-clips or springs are hidden somewhere. This way there's less chance you'll loose parts or some pieces jump away: you know what to expect.
When searching for bad repair jobs, also pay attention to bad soldering.
Solder should be shiny and silver. Bad solder will look gray and dull. While it may still work, it's better to do the job right (at least if you know how to solder correctly). Remove the bad solder and reflow the connections, as they will fail one time in the future.
Pay special attention to springs.
They're used to push plungers to their initial state after a coil activated. Sometimes they are broken or are mangled in between a plunger and the coil edge. Or they've chewed up a Bakelite part. Replace parts if necessary. Because even if it works now, if it doesn't look right, it will cause problems later.
Some people just clean everything, every part. They even replace coils if they're dirty, or replace the paper wrappers so even the coils look like they are new.
This may sound extreme, but if you cleaned every other part underneath the playfield, you want the coils also to look as new..
Also check every assembly to see it's still tight enough to the playfield.
Replace missing screws, especially on heavy assemblies. If screw holes became to worn out, fill them with broken tooth picks and wood glue.
Certainly remove and clean under-playfield ramps, even if it's difficult to remove them.
They probably have never been cleaned before so will be very dirty and are the major source of dirt which comes back on the playfield.
Clean light boards.
Remove all the large green light boards. Then you can clean every light bulb and light insert on the playfield.
Also clean the green PCBs themselves. It may be necessary to resolder the pins on some PCBs if they have an intermittent contact.
Label the boards when you remove them, as sometimes a game uses a lot of similar boards, so you know exactly where each came from. Usually screw holes will be a bit different, but you'll save time if you don't have to search where each went.
If light bulbs which are held in light boards don't work or intermittent, try to remove the black socket and push the two metal pins a bit upward. This way they'll apply more pressure to the PCB when they're screwed in and make better contact.
Sometimes when light bulbs have been removed too much, the metal part of the lamp holder has made a
large scratch into the solder of the small board. The light bulb will not work anymore or make intermittant
contact. Just heat your soldering iron, add a very little bit of solder and reflow all the solder on the pcb.
This will make it smooth again so the little lamp holders make good contact again.
It is best to clean every PCB underneath the playfield, especially if they're very dirty. Usually the black dirt on them is also magnetic, which sometimes causes weird problems. I clean most boards with a moist cloth (with Windex). You can also use a wide paintbrush but be careful it's not a type which creates static electricity.
Also check for 'hacks': bad repair jobs and try to correct them. Only do this if you know you can solder/repair the board better than who did the bad job ! If you're not sure and it works, leave it the way it is..
Clean light inserts. With light boards removed, or single light bulbs bent away, it is possible to clean all light inserts from underneath the playfield. You will be amazed how much difference this makes (the game will become a lot brighter) ! Most people use a q-tip dipped in Windex. As q-tips wear fast, I use a small square artists paintbrush.
Also remove the flippers from the game. They probably need a rebuild, or at least you have to check their condition. And you can't clean the top of the playfield well as long as they are on the game.
If you really want to clean the wire harness, there are two options.
Use a small portable steam-cleaner to spray it clean. Make sure to aim it away from the playfield and important parts !
When you do a complete playfield swap and the wire harness is removed (and coils are not connected to it anymore) you can even put it in a dishwasher.
Disassemble and clean the ball trough. This type of ball trough used by Williams often has wear in the middle groove. To prevent pinballs from hanging up you may have to file the pitted border smooth..