Fixing a 70's Rockola 460 jukebox

and good morning it's a rainy day in Pittsburgh it's a Tuesday so we're going to do a video on refurbishing this ruckle of 460 that I just got in some of the information will be information it was already covered in previous videos but there were several challenges with this box that I thought would be of interest so we're going to go over that we're going to do it in outline um format here go over the steps that I feel are necessary to bring these boxes back to life and uh on and then at the end we'll go over some specific problems with this box I hope you get something out of it'll be about 20 minutes here's you're going to need to go over everything even if they do work the components uh so don't do that if you're insistent then at least take off the connectors to that go to the fluorescent lights and also to the the amplifier Molex and then if you power it up you're not likely to cause major trouble but let's leave it at that now I go ahead and service the casters now um you can see this one has the ball bearings there and so put some oil on it and do that for all four replace any Caster that doesn't have the ball bearings it just makes life easier vacuum out the cabinet bottom don't be too indiscriminate here there will be some coins behind the coin box usually look for metal parts that may have dropped to the bottom uh that'll give you a clue as to perhaps what was broken inside and what you may have to order let's just leave it at that and now we're going to service the power supply this big beast here that's on the back door of most of these boxes we all talked about the line in the core the fuses the circuit breakers now this one had two bad um circuit breakers and I just wanted to show you that you can replace a circuit breaker with an inline fuse here 1.5 amp is what I use I believe these were 1.4 amp in the schematic that's that's certainly um acceptable um now um we already did the capacitors up don't um forget this little jumper guy here uh there can be a dirty Connection in there sort of out of sight out of mind but at least reseat and clean those uh uh connections there you do the three electrolytic caps we talked about the bulb now there's a current limiting bulb that goes on after the stop relay kicks in uh you'll see that flash during the selection process but before you get to that at least take this bulb out and be sure this filament is good they usually are actually but please check that now confirm the AC and DC voltage is then once you've done all this and I have that sheet here from a previous video so this is your Mech plug Mech power here this is what you're supposed to get those are the voltages just look at it quickly this was on a previous video in case you missed it here's the selection system which you're supposed to get you use your multimeter and this is the amplifier uh Molex the main voltages being the 46 volts with a center tap here on the on the left so do all those things if those voltages are good you can return the power supply to your cabinet and we'll go on to the next step next we'll go with the mechanism and record changer now we've covered a lot of this before I'm going to go through it quickly look for missing and broken parts a common broken part would be the gripper assembly here sometimes this little appendage gets broken look at that obviously look at the gripper bow that's fragile you must treat that with respect and then there's many videos on how to free it up and make sure it brings the record out sits it down you want to do that with the motor removed so that you can do it by hand and get better visualization now here's a good visualization of the alternating dog down below it it goes up and down with this spring to go between the record size now you must service this it has to move oil it until you can't oil it anymore because it has to move completely without friction once you've done that you can put it back in the tract and oil the tract very very important and I just wanted to show this again um and clean the circuit boards both the right end and the readout circuit board reseat the play control relay reseat the write-in relay and the K4 relay removing clean the readout arm we did that free up the gripper assembly to be sure it's motion is correct replace turntable grommets they're almost always brittle and you get much too much noise coming up from the turntable motor and sometimes the turntable collapses down underneath because they're not being supported so always replace the three of them these are available uh multiple sources Victory glass hasn't as good a price as any and then um to check these micro switches on the back we've talked about this but here's a good visualization clean these blade contacts and be sure the the connectors are in good condition this is very important uh okay perform any adjustments replace the motors plug in your Mech connector and then try to manually push a lever and see what happens we'll do that in a second now I want to show you something here that was an unexpected uh surprise this is not common but if you do enough of these you're going to find it and sure enough here we are missing a pin it's 104 which the pin is here see there's no pin there that's a big problem unless you just want to leave a blank in your title strip holder with no record you can do that as a homeowner play 79 records instead of 80 but when you're refurbishing I had to make this right now fortunately I had another Pin Bank and I just swapped it in but if you had to go in here you work from the other side that the nuts upside and take off all the nuts and here's what it'll look like inside this is the um read in arm with all the little connectors in the readout arm read outside is simpler but here's where the problem is there's a screw here that tethers these two rods that hold this the um ends in and it'll get loose and then this this pin 104 or 193 those two that are right next to the where the Gap is can fall off and oh my it's a couple hours labor I hope none of you have to do it I just wanted to show what the anatomy is here on the inside of this uh Pin Bank hopefully you'll never get to see it but since it showed up I thought I would mention it let's move on okay so you put your power supply back in and you can just simply connect the mechanism plug you can leave the selection system an amp plugs off now because really what you want to do you put your Motors back on you have it in the home position just simply manually make a selection over here and be sure that the um you know now that the play control relay Works your wobble plate switch is uh working uh there's no record here we'll reach up but you want to be sure that it sits down and has a proper motion if it doesn't you're going to have to make the adjustments now and lubricate but at least you know your readout portion works so now we're going to go on to the selector we're going to move on to the selection system this is the most intricate and requires a lot of cleaning and adjustments a lot of which we've already covered I'm going to go through this quickly and then show you some real life problems with the Jukebox powered up but the selection system consists of the keyboard the selection control panel which is on the back with the k6 and K7 relays the credit unit is very important with the selection system and the contacts there and then of course your connector on the bottom of the box that goes over to the pin bank and the write-in circuit board which needs to be meticulously cleaned as with the wiper so let's just go over this quickly keyboard and solenoid blade switches here they are right here this is very important to clean these and adjust right here here and over here okay the slide switches every one of them again this is a repetitive I know but you want to I put WD-40 on them and then CRC you want to be sure they're clean and lubricated and move for freely that's very important then of course you got to replace your bulbs this is the first make selection Lane and First digit light second digit light Etc these are 53 bulbs and 50 257 bulbs they must be serviced or you're not going to uh oh see now let's go in the selection control panel this is very intricate but believe it or not the problems with this board have been relatively infrequent yes the day is coming soon at these uh tropical fish capacitors are already starting to disintegrate I'm not using this board but if I were to use it I would start replacing these because they're really at their end of life the diodes and the scrs are still are pretty good clean the contacts the group contacts on the side here but look at this monstrosity here and I told you why we don't plug in our box look what this character put in here he put in a drill bit and I should have known better because in the bottom of the cabinet with some drill bit kit this is just downright dangerous these are one amp fuses and this drill bit it probably I would carry 100 amps if it needed to just just absolutely terrible but uh since you don't know what's in these boxes this is a great example of uh why you use caution and before you fire up your box now k6 and K7 both need to be reseeded I don't usually clean the contacts of the enclosed box relays but that they're very important in the selection process look at these four guys here these are the um standard bus connections now each of these need to be taken off and reseeded and cleaned because uh selection last digit 0 1 2 and 3 goes through this um these connectors they're very important four five and six seven go through case K7 and you may need to open this up and watch K7 contract if you select say 104 you'll see this contract the Credit Unit also the ADR relab talked about many many times all these contacts in here must be serviced and then of course on your uh Pin Bank all these contacts now let's go for some real life examples of the uh selection system and in action we put everything back in and we've got our select any single light on meaning we have credit so let's push the first button you get a first digit light push the second button four you get a second digit light and notice you the solenoid kicked in after the second digit that's very important because now when you press the third digit it's going to stay in because it's been blocked by that solenoid it's a that facilitates the third digit staying in so let's do the third digit one four four and nothing happens what's the problem it should write in motor should have started well guess what I forgot to put it in operation pretty stupid so let's see how what happens here all right so that was uh my mistake now suppose I'm gonna just reject this I suppose the right in motor continued to go around and around searching and searching that means you're right in board is not clean enough generally oppose the right in motor came to the right spot it stopped but nothing happened and you didn't see this uh the current limiting bulb go on here in the power supply that's a problem you've got to really research sometimes I reseat the um stop relay which had to kick in or swap it out with the write-in relay sometimes they even take off the cover of this relay to see if it actually works but if you see the light go on you know the relay worked now you should clean those contacts anyway but if the if the current limiting bulb goes on but still nothing happens well then you have to go inside the the Credit Unit there and be sure that you see the uh cancel alarm come across in this uh reset arm working that reset the switch there's a lot of things happen also what has to happen at that time is the wobble plate solenoid had to kick in it's hard to see but it's right down there and that's what facilitates the pin hammer of the pin being hammered if the pin is not hammered then you have to go down on the bottom and reseat that gang connector I already told you about and clean contacts look for loose wire sometimes it's a loose wire on one of the selection because it's just a detective work but there's only about five things you need to check and if you do that and clean everything you should be good sometimes if the second digit does not latch you will have a bad silicone control rectifier and you'll ascertain that by making a different selection of the second digit so instead of one four two make one five two be unlikely two of them would be out and if one five two works and one four two then doesn't them suspect uh one of these uh scrs again not too common but things are starting to fail over the years and um you have to be vigilant okay let's go on to the next section as far as the sound system and amplifier I've covered this a good bit in previous videos I want to make a few additional points today go through and look at your needle maybe replace it if you're scratching this be sure your cartridge wires are intact cartridge should be a sure m44 that was the original and it sounds really the best the amp should have new electrolytic caps that's pretty much standard now check the fuses new op-amp ICS on the preamp board those are right here those units are causing some loss of signal so I'm replacing them they're only about 70 cents all heatsink and Driver board transistors should be checked any tropical fish capacitor that's in the signal pathway should be replaced and looking at the schematic in the on the preamp board you have three of them C1 C6 and C9 and they are right here here here and this big one here replace those they are causing loss of signal and also over on the um driver board the first thing you run into is C 26 there now c26 on the driver board is right there okay that has caused loss of signal and two out of 32 amps so I replace that every time um connections on the back back door for both channels should be on number four if only jukebox speakers are used clean the volume control prongs and mute relay contacts reseed it replace the crossover caps on both tweeters now in this box it's a there are 15 ohm non-polarized but since I can be cheap at times you can put 222 microfarad 100 volt capacitors negative to negative and then the positive and positive will be on the outside and that creates a non-polarized capacitor um solder soldered in it goes over the tweeters that's to protect the Tweeter from higher you know base frequencies and um you don't have to be exact at 15 is what's in the um jukebox but putting two 22s back to back results in 11 microfarads hey that's good enough and it sounds good but do that do something to prove put your uh leaders I on some important um the woofers should be five to eight Ohms a tweeter 12 to 16 ohms just be sure the speakers aren't open now the last thing I am having trouble with and hasn't really shown up much in the discussions about AMP is the um tone control now the signal comes in on 11 I'm sorry 12 and 13 and goes out on 11 and 14. um I had bad signal coming in on 11. and good signal going out on the output so something was wrong in this board well there's not a whole lot there except slide switches the mute circuit and a bunch of capacitors so I started replacing capacitors I don't have a um a oscilloscope to facilitate um you know that came where this Distortion is entering or leaving but uh it turned out I believe that this slide switch is bad and you can sort of tell that there's this insulation is sliding forward it doesn't happen on the others so um just be aware that these slide switches are troublemakers put some WD-40 on them to lubricant them a little bit then clean them off with CRC exercise them a couple times just to be sure they're not in the same position but I'm just saying these are additional problems that are developing that have to be paid attention to okay that's about it for the amp thanks I wanted to say a couple words about the cabinet now Facebook can be misleading at times and this seller had this box for sale looked very nice and I offered a certain amount and went out there and sure enough both both glass pieces are broken and that was uh unpleasant surprise so I was able to negotiate a a more reasonable price if you run into this you're probably going to have to get decals from Europe jukebox Decor is uh from Greece that's tacos zigguratis and jukebox Revival is from the Netherlands both of them have decals the reason is these boxes are worth about two to three times as much in Europe so it it's cost effective for them to make uh have decals made for the to bring these boxes back over here up till now you could often Salvage a glass off a a junker machine but now the machines the ones that are junked or junked because all the glasses are broken so um those two folks outfits have been a real life saver for me I'm waiting on the glass pieces and as soon as they come in I'm sorry I'm waiting on the decals when they come in I'll I'll get this box on the market now the one problem with rock hole is and everyone says is the cabinets can be um difficult uh to maintain their particle board and if you let this chain go and let the front door flop down it's going to torque off the two hinges down there and that's what happened when I got this box there was another reason I offered less for both of those pieces were you know chewed off so I know it's not very pretty but I was able to glue the two pieces back on then re-screw them on and then I just threw some Bondo over top of it and it doesn't look very nice but it's inside out of sight but and it's solid so I have salvaged this door so I just wanted to mention that otherwise the cabinets are usually pretty good in these machines uh just the uh the front doors that get ravaged oh yes there's another piece on the bottom that I was missing and I was able with a L-shaped um aluminum bar to form it in a uh a little more narrow angle so I could put it over the bottom and then I put some screw holes in it and I made a very acceptable bottom uh they call it a Extrusion piece sometimes you just gotta wing it I forgot one thing when you check the fluorescent light ballast so uh I know this is not a big deal but this looks certainly to be an asbestos pad so I really don't feel like removing this um ballast and checking it I don't really want to disturb uh the asbestos sheet that it's on so what you do you you go to the plug that's coming out of the power supply the black wire and you chip at one end of your multimeter there and then you go up here to where it connects to the top and it's not black there it's it's actually a like a blue put the other end there and that should give you the ohms reading across the ballast without messing with that I I know it's not a big deal but if you don't have to mess with asbestos I would just soon not so um that's pretty much the final issue I have with the county I hope you got something out of this to keep for your next project uh uh I'm not sure what my next box will be I'm hoping to get a 440 uh or uh another 437 in and when I do and if like encounter some issues that I think are of value I'll certainly post another video till then thanks again for watching have a nice day

Channel: william weisel

Views: 1,492

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Id: 8roa78XsY2U

Length: 24min 10sec (1450 seconds)

Published: Tue May 09 2023