Power Supply Testing & Repair Of A Rock Ola 490 Jukebox - Motors Won't Turn

ladies and gentlemen this is Joe's classic video games back with another cool jukebox repair video for you today we have been working on this rockola 490 jukebox and uh it's the Super Sound to so this is the 49-2 I believe uh we've done a bunch of videos on these in the past and people seem to enjoy them because there's not a ton of information out there about this particular model box and it kind of gets a bad rep because uh it had this uh control unit in it the system 2 control unit it was only used in I think the 490 the 494 something like that just a couple boxes and then uh by the time they got to the 498 or something like that they moved on to another uh control unit but they sold a ton of these things and a lot of them are broken so I wanted to show you a little issue that's going on with this one and we're going to attempt to repair it we get a lot of people emailing us and asking us questions about these and calling us because they've got one they're trying to work on so I'm going to show you kind of what one's doing and what we think might be the problem and what you can look at on yours and how you might get it working so this particular one when I plug it in just give you an idea of what to look for and what's going on if I try to scan it I don't get any kind of scan action I do get the turntable moving which is something that tells you something okay we're going to slide this back to off okay and if I go to operate it's trying it should be trying to go back to home position and it's not the turntable's barely trying to move uh there's some stuff going on right so let me show you what to do if you if you end up with one in a similar situation okay the first thing you want to check is to see if all of your LEDs are on on the power supply so if you've got an earlier model of the 490 it will have a slightly different power supply in it this particular one is the 54920 D A and the reason that it's in this one is because like I said it's the 490 D2 so there is a 490 a rockola 4901 and a rockola 4902 they sold so many of them that they redesign the entire power supply kind of right in the middle of the Run Okay so this one is the one that's in the later models so you want to see but if you've got the earlier one I believe it has a more of a a more horizontal thing up here this is the amplifier um but it has a power distribution center uh that has a uh a little board on it with the LEDs on it so you want to make sure all the LEDs are on if one of them is off that's probably your issue now if one of them uh is off it's possible that it actually works and the LED is just burn out but that's um you know I'm just giving you a place to look right if you search the internet for the schematics for a rockola 490 they are out there you can download them for free if it's the 4901 or the 4902 like this one if it's the original 490 I can't find those um schematics so if somebody has some scan them and mail them to me uh but there there is the the rockola 484 schematics which are which is from a year or two before this that has that older style power supply in it um those schematics are floating around so depending on which one you got you need to kind of look and see if it lines up right so you're going to have to get your hands dirty a little bit to work on these though okay so you want to see if all of those power lights are on however there are a couple more voltages that come out of this thing that they don't have an LED for so it could be that these four are working but you have a couple more that are missing I'll show you that on the schematics here in a minute so you want to see if that's working you want to look at your your uh board up here without that working your system two control unit working the the turntable and all of this will never scan okay so let me I can't put this on right now because of our battery set up basically we're not going to deal with this in the in this video because this system here is actually working we're going to deal with the power supply and the mech board okay um but basically if you look up at the top it tells you what those lights mean the left light mean standard pricing special bonus pricing lock in pricing default pricing and then there's one that says normal Al operation okay now when I turn this thing on if I can get Focus back I'm going to turn it off and back on and watch what the light does I'm going try to without knocking the power brick out of the machine all right we're just watching the light people see the one at the bottom right and then see how it went off okay let me get my focus right so when you first apply power to it it's saying initializing lock in that light is on and this light is on over here where it says standard ring okay and so those stay on and then after a few seconds they both turn off and on ours this one one comes on where it says default pricing yours may come over to normal operation the reason that ours doesn't go to normal operation is because we don't have a battery installed so we haven't saved the um the pricing in it to the point where it can move over to that but by the act of it turning this light off turning that light off and then turning that light on what that tells you is that the board is actually working it may not be working fully but it's at least running the code and it's booting up so if yours isn't doing that and this light's staying on or that light stay on you've got a problem with your with your control unit if you've got a problem with your control unit you might be in trouble because you're going to have to fix it yourself basically there's nobody around that repairs them that I'm aware of there may be somebody but not that I'm aware of um luckily all of the chips on that board are socketed there's a front board and a backboard if you've got a couple of them you might be able to swap the boards around and see you could order a new chip for every board every chip wanted if you wanted you know you have to deal with that but we're not going to get into that too much in this video because I actually have a working one in there I also have a working power supply but as you can see with the working board and the working power supply I can't get the basket to turn right we're at we're stuck on a record we're at uh record 190 or something like that okay so what's going on I get people emailing me about this constantly constantly okay let me show you the first thing that you need to check all right there are two Motors that do two different things or three motors actually on this setup right now rockola setup didn't change much over the years it's very similar no matter which rockola you have but this is specifically for a rockola 490 or a 494 um this is the cam okay so this unit spins whenever this is improper whenever it's working properly all right so there is a switch or four switches here that change State depending on where this cam is right and when this cam turns it turns the gears and makes the arm move and all that crap right makes the gripper arm uh function all right it can only be in one of two states it can be where the mechanism board is trying to control the gripper arm which is in charge of grabbing a record spinning it around and laying it on the turntable and then picking the record back up spinning it around and laying it back in the basket it it can do that or it can move the me it can move the uh the basket right it can't do both because if it could you'd break all the records so let's say that it's coming down and the record and then the basket starts starts moving well it would break the record right or it would put it in the wrong spot because the basket moved while it had the record here so once so basically there is a motor that turns the basket around to the to the correct spot once it gets to the correct spot it stops and then and only then it allows the gripper arm uh to grab the record and set it on the record player once the gripper arm starts moving what happen happens is this little switch right here on the top this one which is switch number one they call it there is a little Groove down in there that that switch has fallen into to allow it to open see how the roller is down in a hole there let me brighten it up a little bit so you can see it even better I'm trying to be as thorough as I can on several of these videos so people can see what to check on theirs see how that roller is down in that hole if you're not like that the basket can't turn because it thinks that the gripper arm is up so what happens is when the gripper arm starts turning up this cam turns and when it does it closes that switch once that switch closes the basket can't turn anymore that's part of what turns off the power to the basket so your basket will never turn when you put it in scan or operate if that switch is not open you have to be in that hole okay and similarly your uh your gripper arm will never work unless you're in that hole or I'm sorry disregard that we're just talking about the basket because that actually changes state as that turns okay so there are two voltages that the power supply puts out that there is not an LED for you wouldn't think there would be okay well one of the voltages is this turntable so watch when I put it in scan the turntable starts moving I'm going to show you why that is here in a second there is a third motor that only runs the turntable and it runs off of 120 volts it plugs in right here where it says 120 volt AC turntable power now the two gripper Motors are ran by 28 volts DC and they're ran um I think it's 26 volts 26 or 28 volts and they're ran through this mechanism board that turntable is ran straight out of the power supply so how do they turn it on and off well the CPU is doing that so if you don't have this CPU in there you can't get that to to do that okay let's test that theory shall we let me turn it off and unplug the CPU and let's see if the turn table will turn uh without the CPU plugged in make sure I'm telling you the right information okay the machine is off we're going to unplug these two connectors on the top which are the the power and the signals coming out I'm leaving this plugged in it's just telling the display what to what to do now let's see if the turntable will work with that unplug so we have the board unplugged turntable's not on it's trying to turn a little bit that's some kind of capacitor thing but as you can see it's not able to do anything without that plugged in okay that's because the power supply actually I mean the CPU actually tells the power supply to turn on the turntable what I figured out is that the CPU also tells the power supply to turn on the motors that run the basket so a lot of times whenever people uh email and call and say that their Basket doesn't move they think it's the motor it's hardly ever the motor if you've got this problem your motor is probably fine so I'm going to show you in the schematics exactly what's going on okay so this is a little bit of the rockola 490 schematics now we are looking at the CPU section of you know that control unit so the control unit is running some things I have a a uh a uh plush crane in the background making a bunch of noise so anyway this is on the control unit that box up in the front if yours is working properly it's probably doing this okay so one of the things that it can do is it can send out and receive all these little signals here so one of the signals that it sends out is this run signal with a line over it usually when there's a line over something it means that it's active when low so if that line there goes low then that run signal as they call it is active right so you can see that the board has its way of doing it it has a LS 174 here and that connects to a couple things an LS 32 E3 and it runs through a couple more things and um you know it's it's gated with different signals and stuff and it comes down here and it turns on has another thing here it turns on a transistor and blah blah blah but whatever it can make that run line go low okay so if it were to do that that would be a a low signal right that it's sending out now I'm going to show you on the power supply what it uses that for okay so here is further up the schematics they call this the rectifier PCB assembly which is part of the power distribution assembly so this is that big box the power supply we were looking at now just for to orient you orientate you here are the LEDs that we saw that come on whenever the power is working right so there's two there so if this light is on it is the 24 volts ac light okay if this light is on it is the 26vt DC light if this light is on that means the - 28 volts DC is working and if that one is on it means the 5.7 volts is working so if you've got those four LEDs then you've got most of the voltages but there's two more voltages that they don't mention there's no LED for so one of them is this look switch to 120 volts so switched means they can turn it on and off and look it goes to the turntable so our turntable did you see how it turns on and off depending on where that switch is right so how are they turning that on and off off the turntable by the way just plugs right into there okay how are they turning that on and off with this little baby look at this look at this thing this is a h11 C3 opto coupler photo opto coupler now why in the world are they using that it's because the way these things work this is a little chip inside of the power supply basic basically there is a u like an LED inside of the thing or S I think it's an LED uh that basically when you when you turn it on when you turn on that led there is a little receiver inside of it that can tell when the LED is on and when it's on it turns on this connection now why do they go through all that trouble it's because they want to be able to control 120 volts ac which is some juice with just a little tiny trickle signal over here on the other side if they were to they would need a a you know a straight up relay that'll switch 120 volts ac the thing would burn up and it just it has the potential to short the other things so that this is just an easy way to do it right so how does this opto coupler work well it's getting power straight from one of the um like it's a 12vt line it runs it through a resistor it says it's 1.2 volts DC on this one side and then what turns on the other side so the LED for it to turn on it's literally a light inside of it for it to turn on this side has to be connected too this side is permanently connected to 12 volts through this 1K resistor well what turns this side on it's our run signal that we were just looking at from the the uh the PC I mean the the logic unit control unit 2 logic 2 system 2 logic unit right so why is that important it's because since the turntable is turning off and on depending on where the switch is we know that that run Line's working so here's the schematic of the turntable motor which we you know we're turning on and off on and off on and off and the only way we're able to do that is if the switched 120 is turned on and off and the only way that can happen is if that opto coupler is turned on and off which means that the only way that could be happening is if our run line is being used so we know that's working because the turntable's turning on and off now why am i showing you this is so you can check it on yours right leave your CPU plugged in and see if you can turn the turntable on and off by moving the scan turn um scan operate off whatever see if that turns on and off if it does then you know at least that line is running if the CPU is not running on the um in that logic unit though that you're not going to be able to get that to work okay so then what else does that run line do well here's the here's the interesting one so that run line connects to that and then it also connects through this resistor a 1K resistor right down to here boom right there to that capacitor which which is a cross this coil which is a relay in the power supply okay so if that is not connected then this relay is not pulled in all right one side of the relay is connected to 45 volts okay so 45 volts is coming from over here the Transformer right so one side of the relay is always connected to 45 volts but the the other side doesn't have a connection unless that line goes goes uh low all right so why is that it's so that that same run signal can turn this relay on and off so what does the relay do well if the relay isn't um pulled in then you have a normally connected situation here where this line which is the ground from the Transformer the center tap from the Transformer connects to this 24volt DC line here and basically shorts it out so why does it do that right I may have it backwards of what it does when it's on or off or whatever but basically it connects to there um and shorts this to ground well what that does is it makes this the input to this lm3 17 it's getting 45 volts on one side it's getting ground here uh and it can it's basically turning on and off the switched 26 volts not to be confused with the 26 volts there's two different outputs so there's a 26vt and a switched 26vt so there's no LED on the switched 26vt now I know this is really confusing this switched 26vt is are you ready for it it's how it turns on and off the gripper motor and the mechanism motor so we know that that signal works right where are we we know that that signal Works down here to turn on the relay but it's either not turning off the relay or not turning on the relay or something something's not right and uh that's why you're not getting this voltage out if you check this switched 26 volts with which is a red and blue line coming out of the power supply and it it goes over to the uh that switch we were talking about on the cam on the front of the machine if you check on that red and blue line I'll bet you you don't have 26 volts there and that's why you are not getting your um that's why you're not getting your Motors turning so a lot of people think I think my motor's bad and they buy new Motors those Motors don't usually go bad they're the like the last thing to go bad it's much more like that some of this Craft's going to go bad so you know what usually goes bad that relay so look how they've designed it if the relay is closed you have just shorted this to ground so this 24 volts isn't there because now there's ground uh on both sides of this um uh xener diode here 24 volt diode so it basically takes it out of the equation if that's open now you've got the xener diode in play and it raises this up to 24 volts because it's using it it's basically using the output of the uh the voltage regulator there and all this it's an adjustable voltage regulator right so if this if this little relay is bad that's going to cause you all kinds of problems that's what's wrong with mine I believe so here's the next okay so if if that does pull in it can also send ground to this connection so what does it do well if you look on the schematics see the line going up there it connects up to here which it calls audio control so it says audio system socket it's probably something that turns on or mutes the um mutes the Jukebox or turns on the Juke box there I mean not the Jukebox The Amplifier right so why would they do that well once the gripper arm is doing its thing and it's in this position where it's supposed to be or whatever maybe I'm just guessing maybe the the um control unit turns off the motors the power to the gripper arm and the power to the the uh basket and turns on the power to the output of the amplifier that's why it's all muted until the record starts playing and then you hear it pop on that's what I think that's probably how they're doing it okay so all of that to say if you're if that that's some things to check and the order to check them in to try to tell what's wrong with yours right so if you don't understand exactly what I was saying go back and watch through the video and maybe you'll catch what I'm talking about you want to check your power supply you want to check the lights on your on your logic control unit you want to check to see if the turntable turn turns and turns off which is also important right because that will tell you if this run line is working and then finally you want to check the output this voltage here and see if your switch 26 volts is going out on the red and blue line coming out of the power supply if you if that never comes on then of course your your uh Motors aren't running because you don't have the voltage for them to run so let me show you what the mechanism board does with that voltage so the power cable comes down here and it plugs into that board in the front I was talking about which is the mechanism power board okay now depending on which version of the of the machine you have that thing actually may actually be on the back but it'll say mechanism powerboard right on it right there's a couple different designs like I said there's a little six pin connector that plugs in okay and so one of them is a signal that's called cam one I think that may be actually a signal back to the the board uh there's a there's a um a home switch signal here now that's basically so it can tell when it gets back to the home position there is an A and B and then look here's our 29 they're calling it 29 volts at this point 29 volts DC switched it's that same red and blue wire and it plugs in at Pin five right so if you look on here pin five on the actual board comes down and it goes all around and it comes up here and boom it goes to the fuse so if that fuse is blown of course the board can't use any of the power but that's how the power gets on the board the way they turn off the um the motors is they can be completely turned off by the power supply which is turned off by the um um it's turned off by the CPU now I was just thinking since they use the same line to make the uh um to make the turntable turn on they can't turn off the the motor the power to the U Motors if they have the turntable turned on right maybe the turntable has another way of getting power or something um okay and then there's a few switches I'll show you two on that Cam that can turn things on and off okay so we finally made it to the motors the magazine motor and the gripper motor so you see like if we're looking at the magazine motor so I can't get it to turn right now one side of it and the gripper motor is connected to a red and white wire which comes off of the mech board right and then the other side the magazine motor gets its power through the pink and blue wire that is connected through that switch number one that I was talking about right so this switch if it's down in that hole uh the basket can get power the magazine motor as they call it and then if it's out of that hole it connects back this way which sends the power up this way to P five blah blah blah blah and does some other tricky stuff right so that's what you need to look at so um I'm interested now in how the um when it would turn off the magazine power I guess it would just turn it off whenever it's also going to turn off the [Music] turntable yeah so there's there must still be voltage on that line oh yeah it has to be so there has to still be voltage to the mech board while the turntable's Turning because it still needs to be ready to hang up the reverse the uh uh everything and hang it all back up run the motors in reverse and all of that so it the actual uh gripper motor goes both ways it has to lay it down and then it has to pick it back up again too and put it back in the basket so it has to run either way so they have a little um setup down here where they make it go backwards how does that work pin seven a reverse relay it seems to reroute some of the signals to make the power go to one side or the other all right so anyway all that to say I think that relay is bad on my powerboard so I've ordered one but guess what you can't get the one that's on the actual power supply they're obsolete apparently this is a problem that people are running into in all kinds of vintage audio equipment where they use these little relays that you can't get anymore and so the footprints different everything on it's different so I'm I've ordered a substitute we're going to rig it up in the best possible way we'll consider it an upgrade but we have to replace that and we'll see if uh if that gets us up and running so I'll show you what that little board looks like uh on the bench let's check it out okay folks so I've got the power supply out of it okay this is the board that we're looking at on the schematics there's a few capacitors in there I want to replace so I'm going to order those too all of the fuses are fine um and I've got it set up now be careful if you're messing with this folks don't do this now if you decide to do it you did it against my wishes um so the thing is you can plug this in just uh outside of the machine right and then check your voltages and things from there so if I plug it in and turn it on I've got all four of my lights on right now those lights by the way that doesn't necessarily mean that the voltage is perfect it just means that there's some kind of voltage there okay now this is the relay that I'm talking about this is a I'm going turn the camera instead of turning the machine it is a Potter Brumfield r502 dy1 D 24v DC so that's a 24volt relay and it's just a one pole so it just turns goes from one connection to another uh there a two amp uh the the coil can handle two amps and the one amp draw it can handle one amp on the uh the 120 volts that can run through the contacts that is uh this area right here now again if you look the normally connected shorts over 1 in 4749 which is a little diode okay now with the thing turned off notice I have replaced that diode I've been messing with it I messed with this last night then I decided I better film this with it turned off that diode is at a direct short across it because that's normally connected so we need this relay to pull in and move this away from here to here which will allow this to pull the 24 volts or whatever from the output to make this output properly okay okay folks so we've been ordering all kinds of Parts not all kinds just a few and I have replaced the major capacitors the big bigger capacitors on this little board but our main problem we think is with the relay so here is the relay it's an R 50- E2 dy1 d24 volt DC this thing's completely obsolete they haven't made it in Forever you can't get anything that it's even similar to it because the footprint is strange so these two outside ones here are the coil 24volt coil so when 24 volts goes to that this is the common it can it connects to this um inside post here that's the normally open this outside one is the normally closed okay I'll show you a little drawing of the schematic so if you can kind of tell what that is um basically you know when the coil pulls in it pulls it from one way till it's connected the other way okay if I don't drop it on the floor so the coil if you test the resistance across the coil it's like 700 ohms which should be fine but it just it isn't working so it must be if it pulls in it's not connect conting this pin to this middle pin here it's but this pin is connected to the top pin okay so that's the normally closed position when it pulls in it should change this pin to this pin but it's not working so I googled this thing and there are a few of them out there they're trying to get $200 for this thing used because apparently it's in a lot of vintage audio equipment which must have been where they got the idea to use it in this jukebox so I looked around I said you know what I'll uh I will just order another 24volt relay and then I'll just wire it up and it won't be no big deal so I looked online made sure to get one with the right specs so this one is if you're running one amp through it I mean if you're running um 120 volts ac through it uh it has 1 amp um uh a 1 amp rating on the contacts inside of this so you can run up to an amp at at 125 or 120 volts ac through it but if you're running 28 volts DC which is pretty much what we're running this is like what 26 volts DC you can run up to 2 amps through it right so this thing needs to be rated for 2 amps my replacement one so I look online and I find one and I find one that's rated 2 amps looks pretty good I was like oh okay let me order that so I order it's like $2 order a couple of them it comes in it's this little tiny relay right look at this thing so it's an axicom 1 m07 but it's rated for 2 amps at at 28 volt or I think 30 volts DC it's rated at 2 amps so it's got the same rating but look at it compared to the other one and so I've looked and looked and looked and read and read and read and I read this data sheet and this data sheet I think it's the same rating people it's just really small that's not really the best one to use though uh because it it just it's so small that the leads are so close together that it's harder to to to use right but what I did was I very carefully uh attached wires to it and then put shrink wrap on the wires so they wouldn't touch each other soldered the wire to the legs and then ran the legs down into the board into the five holes that the original relay used right so the two of them are for the coil one of them is the common and the other one is the two contacts that switch back and forth and I got it all wired up and I mean you know I got a some heat shrink on it put a little zip tie on it and everything so it can't short out or anything it's just kind of sitting there it's so small I mean you could you could zip tie it to something else this is not really the best one to use I I wish I had a bulkier one so I may I may order one that's bulkier but it is rated the same so technically it should work okay so how are we going to test it well on the schematics it's got that run signal Illustrated right so that run line comes in and it's basically grounding this up here which is the the uh um optocoupler we were talking about um which turns on the 120 volts and then also through this resistor it will turn on our relay which is this area here which will turn on our 24 volts okay which will make our switch to 26 work right so we're going to try it now I've got the uh multimeters hooked up on the uh output of that let me turn it on and we'll see what kind of voltage we get nothing but it's all on right now if I ground that run line to where it thinks that the CPU is telling it to turn on the Run line oh I'm on AC that won't work there we go so I've Got 24.8 5 volts if I turn the ground the Run line off we have 2.4 volts DC okay we put it back 24 volts so it now should be able to turn on and off the motors very cool okay folks we've been doing a lot of work on the machine we've been uh working on the uh MP the control unit uh the amp uh the mechanism the lighting which was actually a really big problem we had to put a a fluorescent um a more modern ballast in it and take all the old ballasts out and rewire half of the stuff um if you get a problem by the way where your computer keeps going back to initialize and it's doing it over and over again or it sticks over there if you have a light bulb that's blinking it'll make it do stuff like that because it's screwing up the the voltage that it needs to boot okay but I just wanted to show you I've got the lid carefully leaned down here and as you can see we have that new uh relay in there all right so I'm going to show you what this thing is supposed to do when you turn it on okay just so you'll know if yours isn't doing this okay so it's off this is what you should get when it comes on it move just a little bit yours may or may not do that depending on where it's at or that may be a capacitor thing or something um so you've got that and then as it's scanning the turntable will move because it's using that home line that we were talking about now that means that relay is working right put it back in operate and then if I pick a record now I can't play a record right now people but what I'll do is I'll pick up another uh I'll do another small video that shows one plan but as you can see everything is working uh we already had our our control board working so what it ended up being uh was that relay and you can see it's up and running in the cabinet so if you have an issue where you can't get anything to turn um at all it very well could be that line on the power supply so you kind of need to check that and kind of a giveaway um well I don't you know the the turntable moving I don't know if it actually needs the relay to work because it's using that optic actually that that uh coupler so but um there you go I hope that helps you with yours check the relay I believe I've had several that have that relay bad in it um I've had a couple in the past that I swapped the entire power supply out in it and looking back I think that's what the issue was because you'll get all of your voltages but uh if you don't check that switched voltage because they don't really mention it and they don't have an LED for it you may not know that they're blowing me up on the phone people so I hope you enjoyed it uh we'll we'll upload another video of this thing actually playing just so you can hear what it sounds like we've got a ton more videos on especially rockola jukebox repair so check those out on our channel here make sure to give us a thumbs up for taking the trouble to film it for you and uh leave your comments down below now if you want to know how you can support our channel I may have mentioned it earlier but there are links to Amazon down below if you're going to buy anything on Amazon they may have that relay on there if you're going 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