Rock-ola 481 Jukebox Power problem - UK Vintage Radio Repair and Restoration Discussion Forum

cafcaddick · 25th Sep 2017, 8:34 pm

Any electrical/jukebox experts

Have a Rock-ola 481 Max which was working fine a few months ago but has been unused for a while.

Plugged it in yesterday and everything seemed fine but after playing 3 or 4 records the mains power tripped at fuseboard. Switched power back on but immediately tripped again.

I have gone through pulling plugs that power different features - turntable, lights, speakers, amp - but kept tripping mains power after playing for a minute or so. Now the jukebox is completely dead BUT still trips mains power when switched on.

I have removed the outgoing plugs from the power supply so the fault must be related to the power coming in to the power supply unit.

My electrical skills are fairly limited but before I look at paying to have it looked at has anyone got any thought on what might be wrong.

vidjoman · 25th Sep 2017, 10:20 pm

If you have a service manual you should be able to trace the route of the power through the power supply. There may be an interference suppression capacitor wired across the mains. This is a safety critical component and must be of the correct type. Could be various other parts within the supply such as transformer, rectifiers etc. You will only find it by checking/testing each part.

Station X · 26th Sep 2017, 9:46 am

Is it a Miniature Circuit Breaker (MCB) or Residual Current Device (RCD) which is tripping in the Consumer Unit (CU)?

If the former a Live to Neutral fault is likely. If the latter a Live or Neutral to earth fault.

Do you have a circuit for the PSU you could post on here?

julie_m · 26th Sep 2017, 12:33 pm

I remember visiting a forum member's house to examine a Rock-Ola juke box that was blowing fuses, and it turned out to be a short-circuit mains filter capacitor.

It's an easy enough replacement. The machine will work without it, but you might be unpopular with your neighbours.

cafcaddick · 27th Sep 2017, 1:37 pm

Thanks for the responses.

Station X - it is the RCD that's blowing so assume it is an earth fault.

julie_m - thanks for the tip on the capacitor. My brother was an electrician so gonna get him to check it.

Have attached scans of the wiring diagram for the power unit (gobbledy gook to me https://www.vintage-radio.net/images.../undecided.gif) and parts list for the Power distribution box. There's a MFD capacitor at number 66 - is this a possible problem or is it more likely a capacitor on either the Regulator or Rectifier boards attached to the distribution assembly

Station X · 27th Sep 2017, 1:47 pm

No obvious capacitors on the AC input side as far as I can see.

The lights are fed from the AC side of the the transformer, but you say you've unpluged them, so it can't be them at fault.

Your electrician friend should be able to carry a PAT test to show whether there's an earth fault.

EDIT. I see there's a 0.1uF capacitor wired to the light socket. You could try disconnecting it.

25th Sep 2017, 8:34 pm	#1
cafcaddick Retired Dormant Member Join Date: Sep 2017 Location: Greenhithe, Kent, UK. Posts: 2	Rock-ola 481 Jukebox Power problem Any electrical/jukebox experts Have a Rock-ola 481 Max which was working fine a few months ago but has been unused for a while. Plugged it in yesterday and everything seemed fine but after playing 3 or 4 records the mains power tripped at fuseboard. Switched power back on but immediately tripped again. I have gone through pulling plugs that power different features - turntable, lights, speakers, amp - but kept tripping mains power after playing for a minute or so. Now the jukebox is completely dead BUT still trips mains power when switched on. I have removed the outgoing plugs from the power supply so the fault must be related to the power coming in to the power supply unit. My electrical skills are fairly limited but before I look at paying to have it looked at has anyone got any thought on what might be wrong.

25th Sep 2017, 10:20 pm	#2
vidjoman Dekatron Join Date: Jun 2013 Location: East Sussex, UK. Posts: 3,327	Re: Rock-ola 481 Jukebox Power problem If you have a service manual you should be able to trace the route of the power through the power supply. There may be an interference suppression capacitor wired across the mains. This is a safety critical component and must be of the correct type. Could be various other parts within the supply such as transformer, rectifiers etc. You will only find it by checking/testing each part.

26th Sep 2017, 9:46 am	#3
Station X Moderator Join Date: Jan 2003 Location: Ipswich, Suffolk, IP4, UK. Posts: 21,289	Re: Rock-ola 481 Jukebox Power problem Is it a Miniature Circuit Breaker (MCB) or Residual Current Device (RCD) which is tripping in the Consumer Unit (CU)? If the former a Live to Neutral fault is likely. If the latter a Live or Neutral to earth fault. Do you have a circuit for the PSU you could post on here? __________________ Graham. Forum Moderator Reach for your meter before you reach for your soldering iron.

26th Sep 2017, 12:33 pm	#4
julie_m Dekatron Join Date: May 2008 Location: Derby, UK. Posts: 7,735	Re: Rock-ola 481 Jukebox Power problem I remember visiting a forum member's house to examine a Rock-Ola juke box that was blowing fuses, and it turned out to be a short-circuit mains filter capacitor. It's an easy enough replacement. The machine will work without it, but you might be unpopular with your neighbours. __________________ If I have seen further than others, it is because I was standing on a pile of failed experiments.

27th Sep 2017, 1:37 pm	#5
cafcaddick Retired Dormant Member Join Date: Sep 2017 Location: Greenhithe, Kent, UK. Posts: 2	Re: Rock-ola 481 Jukebox Power problem Thanks for the responses. Station X - it is the RCD that's blowing so assume it is an earth fault. julie_m - thanks for the tip on the capacitor. My brother was an electrician so gonna get him to check it. Have attached scans of the wiring diagram for the power unit (gobbledy gook to me https://www.vintage-radio.net/images.../undecided.gif) and parts list for the Power distribution box. There's a MFD capacitor at number 66 - is this a possible problem or is it more likely a capacitor on either the Regulator or Rectifier boards attached to the distribution assembly Attached Thumbnails

27th Sep 2017, 1:47 pm	#6
Station X Moderator Join Date: Jan 2003 Location: Ipswich, Suffolk, IP4, UK. Posts: 21,289	Re: Rock-ola 481 Jukebox Power problem No obvious capacitors on the AC input side as far as I can see. The lights are fed from the AC side of the the transformer, but you say you've unpluged them, so it can't be them at fault. Your electrician friend should be able to carry a PAT test to show whether there's an earth fault. EDIT. I see there's a 0.1uF capacitor wired to the light socket. You could try disconnecting it. __________________ Graham. Forum Moderator Reach for your meter before you reach for your soldering iron.