Troubleshooting a dead 1977 Williams Hot Tip Pinball Machine

all right ladies and gentlemen this is joe's video games shooting a little video for you here of a pinball machine that we're working on um people have been asking us to do more tech repair videos so we figured we'd shoot a few because everybody seems to be interested in that this is a williams 1977 hot tip pinball machine it's very old one of the very first uh solid state games um we got it in and it's not doing anything when i turned it on the lights flashed a couple times then went off then you turn it back on back off and you can't get it to do anything so i opened it up start with the basics folks look for fuses so uh we've got of course everything plugged in in the back and of course this is just fresh we just got this in so it's a little dirty inside you can see all of that is the telltale signs that it's probably had mice in it at one point but if you look the power comes in right back here in the back and i'll try to zoom in on that that is the fuse holder if it'll focus for us here fuse holder and the fuse is sitting out halfway now um that's obviously my problem or at least part of my problem but that fuse has live voltage going through it to it whenever you first because that's where the power comes in so i've unplugged the power cord and i looked at the little card under it and it said that this should be a seven and a half amp fuse zoom back out here should be at seven and a half amp fuse it looks really bad it may even be the original one um i tested it it's still good but it just wasn't making good contact in that holder so i'm going to uh actually put an 8 amp fuse in because i don't have any more seven and a half amp which is kind of a weird size you shouldn't really go up in voltage but i don't have any sevens either so i do have eights and it's just a little bit up in voltage so i want to run with it of course we'll watch it but uh obviously the first problem with this machine so we'll put that in and then see what happens all right folks so we uh we got this play field slid out a little bit so we could get in there and look at that a little better and basically what we found was this was a really old fuse holder the original one and as you can see the connector like the holder part has all been up messed up these things are pretty cheap and don't do that great of a job of holding the fuse so we put a new one in and got it secured in there nice and put a new fuse as well just because the old one looked pretty bad even though it still tested fine but it had rust on it and just was corroded looking and um needed to be replaced in our opinion and we also vacuumed it out a little bit here's what the back box looks like everything looks clean um it's all original though doesn't look like it's had much work done to it um so it's going to have to we're going to service all this stuff but we're going to try to see what it does when we turn it on so be back with that all right folks so we've got the back glass out just for a convenience and we put the play field back down made sure everything looked clean under there the fuse is good so we've plugged it back in and we're going to turn it on now and see what happens all right so this is pretty typical this is a williams game um uh the valleys and stearns are a little different the god lives are a little different but basically on a williams game when you turn it on it should pretty much immediately boot up because it doesn't have a self-test really that it does like a diagnostic that it runs through that takes any kind of time so we get these in a lot like this where uh people will actually say well it's it's it's it turns on but it's just it won't kick the ball out or the flippers don't work or the scores don't work well actually nothing's working the only thing that's working right now is the general illumination which is uh like the simplest circuit on the on the machine so basically the the uh the game boards are never booting on this game it's never even turning on you're just getting power to the light bulbs that are always on uh and they use uh i'm not sure about in williams but i think it's about six volts ac um so basically this would be a probably a power supply problem because uh you're not even getting the board trying to boot so we'll uh we'll check that out let me let me open the door and then we'll be right back all right so since this is all original i probably shouldn't have even turned it on without disconnecting the board the main board but uh i'm gonna have to rebuild everything anyway so it's not that big of a deal if it fries something or whatever it'd just be something else to fix while you're doing it but basically the power runs up through this little connector here and then goes over here to these bridge rectifiers which in their infinite wisdom they never put fuses on or anything um and runs up here to the the power supply board so basically i'm not sure what part of the power supply board i believe maybe this area right here actually controls the general illumination so we're getting that but uh the part here is the high voltage for the displays it may be working but the computer is not telling it to send any voltage to the uh i mean any uh information to the displays and then uh you've also got um well if i can find oh yeah here obviously the five volt uh rectifier here that basically is or power supply here is it's basically uh creating five volts for the and 12 volts for the main mpu board to run so i bet if you check the power on the mpu board you would not have 5 volts so we will test that theory be right all right folks so just quick and dirty i put the probes up here on the voltage plug on the mpu and we're getting nowhere near 5 volts or 12 volts on the other wire so basically the power supply isn't working properly so that's going to need to be rebuilt so that's our next step we're going to take all this apart take the power supply out test things replace things blah blah blah blah and we'll be back in a in youtube land here just a few seconds showing you what a rebuilt williams power supply looks all right folks we're back we had to do some extensive work here i'll show you some of what we did basically uh we were right the power supply wasn't putting out the five bolts it was supposed to so we replaced the power the voltage regulator replaced the five volt filter cap which is a must on these replace the two diodes this is a system three and it was actually like the first game that williams made so this was their earliest uh earliest version of all of this um and so after we did that we got the five volt right um and uh tested it everything's cool with that but the voltage the score displays weren't working we weren't getting any voltage out which is weird because it makes negative 100 and positive 100 and both of them are gone so we started looking and the input voltage wasn't there so this transformer down here puts out about five different voltages and one of the voltages it puts out is 90 volts that goes through all this blah blah and makes the uh the displays work but the 90 volts was missing so the transformer itself was bad it put out four voltages but the fifth one it didn't put out which is tough i mean that's a big deal because you can't really get the transformers anymore and you especially can't get a transformer with five distinct voltages but luckily um we were able to install another transformer we've got so most games won't have this over here that's a hundred volt transformer and so we were we had one of those around because we use them on arcade monitors a lot and so we were able to run voltage in and then you get 100 out this is just an isolation transformer from a monitor actually and uh we were able to run the 100 volts over now you're only supposed to put 90 volts into it but we put 100 in and it worked and we're getting our 100 out and negative 100 out so all of that seems cool now we've got it where uh the voltage is right to the main game board but we'll show you what happens whenever you turn it on basically everything's cool and then you kind of it's not really booting it's just got some gibberish and no action on the game and the reason for that is because now we need to work on the mpu board which is uh up here and then also the driver board beneath it it's got this connector in the middle that connects the two boards and those are known for having all kinds of problems so we're going to work on those next but we did get the power supply putting out all the correct voltages and everything and we still got a couple things to do like for instance on this one originally the uh the voltage for the general illumination lights on these first two games for williams ran through this connector and then over here to this fuse and then out this connector but they always got burnt up so at some point somebody removed that and put this little fuse external fuse holder in right here and it's actually working really good and everything looks good and it's put together right so we're leaving it yeah i don't know when they did that probably 20 years ago but um it's working and we've got the the uh scored displays working we've got the five volt working and all of that and also the the solenoid voltage is there and the uh the switch voltages there and all of that so now we're over to the uh the mpu so we'll mess with that a little bit see you uh whenever we get that going all right folks through the magic of youtube it's been a couple days and we have got the game actually up and running although not perfectly yet you can see see the number one score it's that's the high score and that is the latest score right there so what we ended up doing i'll just run through it a little bit for you we're not finished with it or anything but i'll just show you what's going on so as you remember the uh fuse holder was messed up so we weren't getting power up to it and then once we got power up to it we weren't getting a 5 volt so once we figured once we rebuilt the power supply we started getting the 5 volt but then we weren't getting the display voltages so we figured out that the transformer wasn't putting out the 90 volts it was supposed to put out we wired in an extra transformer because you can't get the original transformers but so we wired in an extra transformer to provide a 106 volts i believe it is to the power supply board which is still properly properly regulating it to 100 volts there's a couple diodes you can change here to actually make it like 91 volts which is a little better for the displays but we haven't done that yet also uh some of these connectors we need to re-pin and things like that haven't done that yet but we'll get to it another thing you know people always ask us why do pinballs get so expensive from people um it's just because to get the things working you have to do a lot of work to them so this is just a little bit of the work we've done there's still a long way to go but um so there's also connectors you can replace these two little uh solenoid these two little bridge rectifiers down here the little black things uh they basically turn the ac voltage to dc voltage for the lights and for the solenoids so we had a problem where one of them wasn't putting out the voltage and ended up just being a bad crimp on one of the connectors these you're supposed to add a fuse to as well so that's another thing that we kind of need to do you can see someone else has already moved one of the fuses off the power supply for the general illumination so someone did that before us and then we after we did all that we noticed of course that the board wasn't booting so the problem ended up being what it usually is on these is this metal connector here you can see how that's all new basically what happens is the cpu which is uh i believe that's it the uh the cpu chip and the roms are basically trying to talk to these three pia chips they're called peripheral peripheral interface adapter chips 6821 chips and so basically it's trying to talk to those to boot up the game this is all happening within less than a second it's a little data back and forth across this connection that connector was kind of a weird one and it gets old and messed up so you need you need to replace that basically so once you replace it it makes it more reliable we also took all of the chips out of their sockets and cleaned them we didn't find any bad sockets but these are this these william game williams games are known for having bad sockets so sometimes that's a problem we also took the old battery holder off that had just a minor amount of corrosion uh nothing major at all just a little tiny bit and put a brand new one in um that will install batteries in we may rig it up and put in a remote battery holder so that there's no possible chance of damaging it with uh alkaline in the future we resoldered all of the connectors on the main board we resoldered all of the connectors on the bottom board we tested all this stuff while we had it out and i found a couple transistors that were bad so we changed them while we had it out now on these you also have these resistors right here see how those don't look too great and they put off a lot of heat and they burn up all of these are actually still within spec even though they look bad you can replace all those too so that's another thing that we'll probably end up having to do um and all of that just to get the game working you know several hours worth of work just to get it working and we're not even done yet so now that we've got it up and running you can see that first to score changing is kind of the only way you know that it's running now that we've got it up and running you can see we've still got a lot of work to do we've got lights that are twinkling that aren't working quite right we've got this one display here that isn't doing what it's supposed to do we've got this display down here where the bottom line of all of the digits is missing um so next up we'll have to mess with the displays a little bit but we'll probably go ahead and end the video because i just wanted to see and show you what it kind of takes to walk through one of these and and get it up and running again the play field we've we've taken everything off of cleaned waxed put back together blah blah blah blah but again it still needs some some work it still needs uh there's little issues going on all over the place some of the light bulbs like this one the socket probably needs replaced etc etc so but let's show you a little bit of a repair video i know people like seeing kind of how we how we go through these things so basically we got this one in it wasn't doing anything and now we've got it to the point where it'll play albeit not perfectly yet so we've still got several hours worth of stuff to do to it but whenever we get everything done we'll film a little video of it this is william's hot tip from 1977 we'll film a video of the game after it's complete and finished so look for that video we'll see you next time