Rockola 477 Power supply

Hello to all,
Just joined this group, looks very good.
Can anybody tell me where I can obtain a schematic for the power supply regulator board. I'm in the UK. I've just bought the Service Manual but its missing. Regards, Dennis.

Hi Dennis,
Welcome !
If you paid for a Service Manual ONLY, you got what you paid for--But if you paid for a Service Manual Package, it should have contained that schematic, IMHO. Check the list of "legit suppliers" or "usual suspects" listed above, and see if one of them has it available---
Ron Rich

Ron,
I bought my Service Manual from a UK Dealer. I had no idea it would not contain all of the schematics. It did not specify that it was incomplete.Its only half a Service Manual without all of the schematics. I am reluctant to spend any more money on this Jukebox. I paid twice as much as what is was worth, described as fully working. I've since spent £300 on spare parts & Manuals. I will just have to trace out the cct myself. So far it owes me £1100 and I've still got problems. I think its time to call a halt on my spending. It works most of the time ok but the 9.6 volt regulation is not as good as it should be. Having spent £35 on one Service Manual, I'm damned If I'm going to buy another. I don't mind buying the schematics but It doesn't seem that they are sold separately. Wish I had kept my NSM Presige II. Well, you live and learn. Thanks for your reply. Regards, Dennis.

Dennis,
Have you contacted the supplier ? If so, what does he say ? He can't supply them or, they are extra cost ?
I sure hope he's not one of the suppliers listed above ?? Ron Rich

Ron, I bought the Parts List from the US also a tested logic unit. The UK dealer was only advertising the Service Manual. I am going to contact him this morning to see if he can obtain the schematic of the power supply unit. He did include the Audio Amp schematic. My NSM Manual had everything in it so I just assumed the Rockola one would. Ordering from the US means I have to pay 20% import duty so I try & get stuff from the UK but its not always possible. I am waiting for new speaker cloth at the moment from the US. Yes, you're right I should have bought the complete package, didn't know where to look for that at the time or even know I needed it. I am now a poorer but wiser man. My 477 is belting out some Rock'n'Roll this morning but its a bit unpredictable. On switch on it either works or it doesn't. If I don't get the "Record Playing " display coming on I know its going to act up.' So I'll see what respose I get from my UK Dealer. Best regards, Dennis

Dennis, what is exactly wrong with the jukebox, if there was a faulty regulator board, the machine will not play at all, the three led's on the regulator board should be lit up when the machine is on and on occasions if the 9.6 vdc does not read exactly that the machine will do weird things, the adjustments for this are in the manual
regards
clones

Hi Clones,
Well the 9.6 volts drifts around a little bit, (9.55 to 9.65 volts approx.) I have cleaned the trimpot & checked for dry joints. When I switch on, the record playing display does not always come on. Recently it would let me select & then play that song. The record playing display would not keep up with the records selected & stick on the first record. If I selected 3 or 4 records, it would play them all but still display the first one. After that it would not let me make further selections. since I renewed the smoothing caps in the psu & had a look at reg board, its a lot better. I've tried another Logic Board but it didn't make any difference. When I do the "Test" on the Logic board it plays in the correct sequence. It worked fine this morning, played 8 selections when required & showed the correct display. So I tend to think its either poor regulation of the 9.6 volts or as "jukeboxmel" suggested a timing issue. Gonna change the 1k trimpot on Reg board tomorrow & see how it goes. Regards, Dennis.

Dennis
Maybe check the rectifier board inside the power supply unit, i had problems before with power regulation as a result of a faulty rectifier board
regards
clones

I've checked all of the diodes in the psu & they all appear to be ok. Dennis

Hi All,
I generally find problems such as this (weird-intermittent--strange), to be caused by poor "interconnections" at the plugs/sockets/edge connectors. I most often find a common ground (earth to you guys across the pond), especially in cases where more then one "supply" (AC-DC together ?) is "grounded", on the same terminal. What is happening is the connection is heating up--and opening, just for nanoseconds--not long enough to be seen by any meter--. The only cure I know of for this is to jump the connection(s), if after having cleaned, and "reformed" the pins, it continues to be a problem. Ron Rich

Ron,
Yes I'm not too happy about some of the ground connections, been intending to clean them up.
I've cleaned all of the plugs & socket pins as much as possible & checked them with a multimeter but as you say, things can change when they get warm.
Dennis

Denis,
I do not re-call which type/brand of plugs are used in that model, but I often just remove, and replace all grounding "pins"--Also--on some RockOla's, they used a common post to tie many ("large", green/yellow wires) ground terminals together--somewhere in the phono-- I have found out (the hard way) this can be a problem, as it gets "gunked up" in between the terminals--and in some cases, some "joker" has installed a steel nut, and or washer--this needs to be brass only ! Ron Rich

OK, Ron.
All noted.
I'll check them all.
Thanks for the info.
Dennis

Hello Dennis,

Welcome to the forum, I can not help you out on the Rock Ola but there are a number of dealers that may be able to help you out in the UK.

As Ron says connects can always be a problem on all jukeboxes and interconnecting looms can give loads of problems, most people meter these out and assume that they are good but you need to remove the pins from the connection to see if they are tarnished or do not have enough pressure on them to make a good connection. Power connection tend to be the worst and in some cases you can see burning on the plastic molding of the connector.

Regards
Alan

Alan Hood
ami-man
UK

Yes Alan, I know you are right.
I've spent time trying to make sure that all my pins are tight, squeezing pins in etc. In the Rockola there are far too many plugs & sockets to cause problems.
They will be designed like that for ease of maintenance which in itself means more maintenance. Of course it wouldn't really be practical to bypass all of these plugs & wire straight through in case you wanted to swop something out.
Regards, Dennis.