Fixing an 80's Drew's Tiger Paw Plush Crane Claw Machine With Schematics

ladies and gentlemen this is Joe's classic video games back with another cool arcade game repair video for you today this is a Drew's tiger Paul crane machine that's given us some trouble and we're getting kind of deep into fixing it so we thought maybe we'd film it just because U it deals with some of the schematics and people seem to find schematics interesting so we'll go over that just a little bit but this is this is an old school crane I think it's from the late 80s usually you can tell how old a crane is by the joystick if it has a joystick it's probably later 80s if it if it has just two buttons it's probably earlier 80s but this particular one isn't a super common it's called a Drew's tiger Paul and it was by this company that was I believe down near Clemson South Carolina which explains the fascination with tiger PA right and it just I I always like these because it has a real 80s look to it I almost fell over on my motorcycle here almost wrecked my motorcycle I always uh I always like these Drews because it it just has such a chuckecheese ShowBiz Pizza look to it you know with the orange and the yellow and everything I don't know if they were ever Chuck-E-Cheese or Showbiz but you get my point but this one has such a strange problem I figured I'd film it while we're trying to fix it so on the back here we have pulled the board set out and we're working on it right so I'm going plug it in and show you what it's doing and then we're going to look in the schematics and see if we can figure out how to fix it right okay so we're at 0000 Z like we should be so we're going to add a credit right let me open this top here okay so we're credited up now watch what happens when we move basically everything works great on it but it's super slow crazy slow look at that and it's everything is slow look it even it even runs out of sound finally it timed out so it's going to try to get all the way back up since it never hit the bottom it didn't even close the claw that part works too and then it slowly goes back to home right and so it barely made it let me do it again so that you can see the claw closed so you know that the claw is working too we'll try to grab that piece of plastic [Music] there okay so the claw is working the left the right's working the forward and back's working but everything is super slow crazy slow right so that's what we've got to figure out so what I'm going to do is I'm going to grab the schematics and we'll look at that and see if we can figure out why this thing is doing this okay so in one of these a while back I found this manual which is you don't see this one too often Drew's tiger paaul service manual made in the USA and so it was made by Drew Industries Fair Forest South Carolina for music only you know have to get around the gambling laws some way right now by the way this game isn't really worth much money and that one's not even in that great a shape so this is almost like a hobby that we're fixing this one cuz it we're not going to get a bunch of money out of it but we got it really cheap too so so we're we're just trying to fix the thing and it's almost like a puzzle like it's working but it's just working really slow surely we can figure that out right surely we can figure that out so um I want to show you I've got the schematics too I want to show you how they did this so um it gives you error codes if it doesn't hit a switch right which is fine all of that works fine um it has some dip switches here to set how often you win so on a lot of them they have a knob where you can turn you can change the the strength of the claw but on this one you it's done by dip switch so you actually tell them average number of plays for each piece vended and it has a little sensor to tell how many when tell when somebody wins and then it adjusts so that uh uh uh below you will find a table that allows the operator to vend a product at just about any price desired now people say oh man what a ripoff this thing's a ripoff in some ways yeah but in other ways I mean if you put a toy in there that's a you know 75 cents a piece to buy you can't have it where that people can win every time youd go broke right so you have to somehow control how often people can win again these are to make money that's the whole point of them you know and not only do you have to have make enough money to pay for whatever you've got in it you have to make a profit and you have to make a profit for the location that you've got the game in so you can't let people win all the time so power supply this machine operates on four voltages from the power supply they R 5 volts DC regulated which is for the CPU so that's the electronics to run the you know the switches and the little display and everything and the the coin Mech well that's working right all that's working fine 12 volts DC regulator for the audio supply you heard the sound that's working okay and then there's a 12 volts unregulated for Motors in Reverse which is kind of strange that a way to put it and then 24 volts unregulated for Motors forward that's kind of a strange way to put it does it go it goes twice as fast forward that it does backwards ours isn't going fast at all right so it says please note that 12 volts unregulated actually run approximately 18 volts and the 24 volts unregulated run approximately 36 volts okay so it shows you all of the wires and how everything connects and then you get over here to this power supply schematic and so there's a Transformer the power comes in and then it creates two voltages here and here and this is AC because it's power out of the wall ac Transformer doesn't make things DC so it's still AC and then it has a center tap well look at the way they've done this so the two voltages come over here to these in the middle of these four diodes which is a bridge rectifier so that's how you turn voltage into DC so if you design it like that on this side of the diodes is going to be your ground and you can see sure enough down here they call it the logic ground which is connected to the power ground right see how they're connected right there so they're the same basically the logic ground runs over here to the 5vt supply uh and the 12vt supply to make the the the the uh voltage for the logic chips on the on the uh motherboard right and then so this is the ground coming off of these diodes and then on this side is the DC positive voltage right so this is this Transformer puts out 24 volts and it's a little um it goes a little bit higher than that but DC whenever you turn AC into DC it actually increases the voltage so on this side of the bridge rectifier the voltage is actually 36 volts right so on one line it runs over to and see these two are connected together so this is the output of the voltage the the Transformer the bridge rective it's the output comes over here to motor power right 36 volt and then over here it comes to claw power 36 volts right I believe that there's some way that the the motherboard can change the claw power I think that's how they control how often you win so I think that changes all the time but this part doesn't you know the the 36 volts coming out of the power supplies it's always the same okay and then look at this the center tap so a center tap is halfway so um compared to this line there's 12 diff 12 volts difference so if you measure between this line and this line you get 12 volts if you measure between this line and this line you get 24 volts so the center tap is halfway right it's not really a ground because it's AC so it's kind it's kind of hard to understand but I don't completely understand it but the center tap is is half the voltage of either one of the other ones so it's actually like 12 Vols or a little bit little bit higher I guess since it's measured in relation to the ground over here it's higher so they've got it it comes off and it runs through one little resistor which is 22 ohms and then it comes over here to what it says is the motor 18vt DC right so they're using the center to make the 18vt and then the bridge rectifier is creating 30 6 volts twice that right so if if this is like way over your head don't worry I don't completely understand it either but we'll I'll show you why this is all important here in a minute I want to show you how they design this thing it's really creative um so let's check out on the schematics these schematics you don't see too often for this game the ones I have even have a big piece missing but all of this is like the the process so this is the processor that runs the board remember all that stuff's working um and so the processor sends over here to this uh peripheral interface adapter chip that sends all these lines out and uh they go over here to this and they read the dip switches and blah blah blah blah blah this is the audio so that that helps make all the all the sound and everything okay and then here's another peripheral interface adapter P 6821 that runs all of the LEDs on the display so it makes the LED display work right but then it also sends signals down here into this area right so this area is all of your Motors okay so the power supply it creates three different voltages there let me find the um where it shows what the too so power supply so we saw the power ground on the logic ground and then the 12 volts for the audio these are the pins that send the voltages off the power supply and then here's the claw 34 volts and it says that it goes to the motor assembly so that's up in the top so basically it's sending 34 volts to the claw and then sending 34 Volts for the motors and it's sending it to I don't know what 18 means I think that's they're saying pin 18 yeah pin 18 on the main connector and then it says Motors 16 volts motor assembly blah blah blah blah blah so the motor assembly is the The Carriage up in the top and then 5vt logic it's sending out to the 5 volt so it's sending some of the power up to the top and it's sending some of the power over to this board right so these schematics are of this motherboard so the area that we're talking about right here are these is this area right here and these transistors and stuff I call them transistors they might be a triac but I've been told that triacs are in fact transistors so anyway if you noticed all of the motors are running slow so does that mean that we've got a bad motor probably not I mean how the hell would we have three of them bad at the exact same time so can we just uh eliminate the motors as being a problem you can't eliminate it but I'm going to go ahead and assume and you know what that means I'm going to assume that the motors are fine because all three of them are doing the exact same thing so either all three of them went bad and are running at half speed which I've never heard of an electric motor doing um or there's something else going on right so here's the north south motor makes it go north and south the on the carriage and all three of them are are running slow so since this one's running slow is it one of these pieces one of these parts it can't be right how could it be one of these and make this one go slow too and so like if this transistor's bad it wouldn't make that one go slow and if this transistor's bad it wouldn't make that one go slow so hell all this stuff has to be fine right if you're going to assume the motors are fine then you got to kind of assume that all this stuff's fine so look at how they made this thing work it's brilliant so you see there the line is broken here so what they're showing you is that these are the outputs of the board and then it goes up to the motor eventually so the motor a DC motor you know it's got a positive and a negative well they're making it work one way and then work backwards so the motor turns the wheel to go across the trolley and then somehow they're able to make it turned backwards how the hell did they do that so they've got a they've got a positive connection and a negative connection on each motor right and so what they've done is on the positive connection of each motor they've connected it to 18 volts which is on our power supply this one here this line that I was saying is going to this resistor and then going over here to the center tap right so they've just got that wired straight into the positive on the motor and the way that they have decided to control these things is these transistors and this the just the whole circuit board what it does is if it sends out you see up here that one of these transistors and so there's there's three sets right so there's one two three so you can look at any of the three they're all the same one of these transistors connects to 36 6 volts which is the the the full power right so remember how we said this one goes up to the to the carriage but the this one goes to the board right so that wire connects to this transistor and that transistor and that transistor and you can see it on the board it comes in here and that line you're seeing there on the top of the board connects to all three of the transistors right so 36 volts connects to one one transistor and then the other transistors are all connected to ground that's what that little thing is chassis ground and so you can see it up here that line coming in there is actually the ground and go into these three right so what it does is this is brilliant they have 18 this may be super common and other things and I just don't understand it but this I was looking at the schematics and figured out how they did it it's brilliant they've got 18 volts running to the motor but they have a capability of putting 36 volts so what they do is the 18 is always on the motor if they would have put ground always on the motor they wouldn't have any way to go backwards so they put 18 going to the motor because if they send out a voltage see the board is connected to the negative side of the motor so there's eight 18 volts on it so if they send out a negative voltage so if this transistor connects ground to that line it makes this zero so now you've got zero on one side and 18 on the other side and the motor turns and goes backwards because it's got 18 volts on it if they connect this transistor to the 36 and it opens up you know the signal tells it to to open well now you've put 36 volts on this so what does that do well there's 36 on this side and 18 volts on that side so it creates a a negative a voltage of 18 volts going this way so the motor goes this way 18 volts so whenever it was saying in the in the book 24 volts for the forward and 12 for the back or whatever they were just talking about this little how they play with this motor by doing that so this this circuit here can send this motor it it's always got 18 on the positive it can send this motor either zero if it grounds it or it can send it 36 so if it sends it 36 there's 18 more this side so it moves or if it sends it zero there's 18 more that side so it moves or it can send it both it can send it half so if it sends at 18 volts and there's 18 volts on this side there's no differential in the power so it just sits there and the motor doesn't work so that's a brilliant way of doing it it means they can make the motor go either way right and that may be something that people have been doing for hundreds of years or 100 years and I don't know it but that's brilliant I don't know how many of the claws the the the claw games they made work like that but that's that's brilliant so um and it may just be simple Servo stuff and everybody's laughing at this but to me it's brilliant um and uh so what we need to do is measure these voltages right so what I did was I took the multimeter and I measured on the I measured the power supply and all of these voltages are correct we've got our 36 our 36 and our 18 but when you measure the um it when you measure the output of this here whenever the game is just sitting their idle this is at 18 so it's sending 18 to it just like I was talking about and it's getting 18 from this side so it just sits there and doesn't move and it's doing that with all three of them right if you start moving if with respect to ground you can see where it either goes from ground to go one way or it goes to 36 to go the other way so in other words the board's working perfect it's doing exactly what it's supposed to do but still you saw how slow everything's moving so what's our problem well what I've discovered is this 18vt line which is this one is a good 18 volts when the game start starts or while it's just sitting there but when you start moving so if the board sends it 0 volts on the other side of the motor you know what I mean so if it if it sends out zero volts to here and it's supposed to have 18 over here what happens is that 18 starts dropping and it drops down to 8 volts so for whatever reason this the whenever the motors start getting power that line drops so it drops down to 8 volts so the motor is running at half spe speed is what's going on it's only getting 8 volts so if you go the other way and the board sends it to 36 volts right well that should make it move you know 36 minus 18 it should move there's 18 volts going to the motor right diff differential but it doesn't do that that line that's 18 starts Rising so it gets up to like 28 volts so there's still only 8 volts going to the motor so either way you move this number changes with respect to ground so it'll be it'll go it's supposed to be 18 and it'll stay 18 when it's just sitting there but it'll go down to like 8 volts if it goes one way and it'll go up to like 26 Vols if it goes the other way I might be measuring it wrong I don't know but sure seems to me like that's why our Motors are slowing down so what I did was I went in and I replaced all these diodes didn't do a damn thing these these two diodes here only control like the 5V and the 12vt so it couldn't be those two diodes but these power diodes here I changed them didn't change a thing so what I've done now is oh and I changed the resistor I put a new resistor in um which the thing I'll show you here in in a minute but the thing's kind of hacked in so I'm not even sure if that's right but it looks like I guess the factory did it CU it's in the schematics you can kind of see where they've if you look really close you can see that at some time they've edited it edited it by removing looks like they removed a straight line and then added the the resistor line it's printed like that but you can tell that's one of the the uh changes that they've made uh so what I'm thinking now is these big Power caps um may be the problem so I've ordered new caps for the power supply so uh it could be this cap here that goes between ground and the center tap that that's leaking or something or you know I don't know how it would be doing up both ways but we're going to change those caps next so that's our next little set so we'll get those in I'll pull out the power supply where you can look at it and we'll try those caps and see if that gets us any better but oh and this is an extra board I have swapped it into and it does the same thing um so I'm pretty convinced that the board isn't the problem that it has to be something in the power supply because I don't see how it could be something in all three motors I could be wrong but um I think it's going to be these caps on the power supply because that's all that's left right or the Transformer or something but usually a Transformer doesn't go bad so we'll get the caps in tomorrow and we'll film us putting them in and see if that gets us anywhere okay folks here's the power supply so the power comes in over here goes through these fuses uh and this line filter goes into the Transformer comes out of the transformer into this power supply um this makes the 5 volts and then the voltages are used for what we were looking at so the only place that the logic ground is and that 18vt line are and the 18vt keeps moving is on this power supply and on all three of the motors so the the power line the um well not even on the motors because it just goes to the board so the only place no the only place that has the 18vt line and the ground line is right here so I'm gonna try replacing these caps these are for the two logic so I they don't really need to be replaced because that's working good but I'm gonna try replacing these caps and see if that uh makes it where that line is more stable hopefully okay folks so we got our caps in we put them on the power supply and that didn't fix anything so it still was moving way too slow so that resistor I was showing you on the power supply that was the only thing left and it looked like somebody had added added it it would just it had two holes drilled in and a trace cut and blah blah blah blah but you see that kind of stuff all the time from the factory and it was on the schematics right so I thought well hell I'm just going to get rid of that resistor because it was right on that line you know and it kind of seemed like maybe that was causing a problem because the line the uh the uh voltage ran right through that line took the resistor off and it fixed it so we still got work to do on it of course but I'll show you that it's moving a lot better now much better right now the voltage for to drop it I guess is different or something because it's not quite as fast [Music] but see if I get might see if I can get Mighty Mouse oh I missed them I'll try it again so that we can see if uh it plays a little jingle whenever you win right let's see maybe we'll just try Mighty Mouse again oh oh maybe maybe oh I might get a couple of them a it's so cool people it's so cool so we got a little bit more work to do on it and then this thing will be slaved so it's got a little cosmetic work still of course um it's it's never going to be perfect look they've they've done some kind of Bondo to the side of it there um and then there's a chip down there too but what we need to do is put locks on it and we've got this problem up at the top so originally this sucker had this mirror up here right mounted here so I just took it off and it had a little rope light around it that runs off of this plug which is the same 36 volts that's running everything else but it has these little look how this thing was made so it's a flat cable that plugs in and then you have all these little bulbs that are 36v bulbs and I don't have anything like that and I believe the game board could flash them or something I don't know but we're changing that so what I'm going to do is I'm going to go to the store and I'm going to buy a rope light that's about 6 feet long and go around the inside of the box like those were and uh splice into this 120 volts that's coming up here here for the lights on the top and I can hide the power thing and everything put the glass back in and put the rope light in front of it and then whenever the door's shut it'll have the nice mirror and it'll be lit up up there and everything it'll look really nice so that's what we're going to do next so I'll uh I'll go grab that at the store we'll clean it up a little bit more and then uh I'll show you what it looks like when we get all done okay folks so this is what we ended up with it came out pretty good really it's got the old school look to it uh like I was saying earlier a lot of the really old ones had buttons on them and people don't like them as much those were the ones I always played whenever I was a kid but um this one actually has the joystick which means that it will be more desirable oh and I'll show you with the rope light let's turn off the lights here you see we added a little rope light up at the top and the mirror back in it has that old 80s look you know pretty cool you can buy stuff like that online or you can buy it at Lowe's I just drove over to Lowe and bought it Drew's tiger paaw like I was saying at the beginning I really like how it's got this like the yellow and the orange and it just that looks very late 7s early 80s to me very cool see if we can win something again what do you think can I do it on one quarter let's see who should we go for do you think we can pick up that big Shrek [Music] doll I don't know [Music] oh no I'm going to have to ask my mom for another quarter nothing but there you go got it all finished up so that's kind of the typical stuff that we have to go through on some of these old ones we end up U working on them a little more than is uh find financially smart this one won't bring a bunch of a lot of money we'll probably we might ask $600 for it something like that um so that that's probably Top Dollar on it so we'll see what happens right so I hope you enjoyed the video of some of the stuff we go through whenever we work on some of this weird stuff I hope you like looking at the schematics a little bit I know people enjoyed trying to troubleshoot on schematics it's a shame that it wasn't actually the Caps I would have looked like such a hero if it really was the caps but it was just that little resistor the whole time um so leave your comments below let us know what you think give us a thumbs up for taking the trouble to include you in the trouble shooting and uh we will see you on the next video hope you enjoyed this Drew tiger paaw