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Post by jukenorman on Jul 23, 2020 14:05:23 GMT
The amplifier gets 46 VAC supply from the power supply. If you look a few topics down the page, I have answered some 460 amplifier questions for somebody else that probably also answer yours!
Norman.
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Post by drkatz on Jul 23, 2020 17:23:54 GMT
Ha! Well now our bulbs are about the same brightness --none.
I'll let you know if I make any breakthroughs! Let me know if you have any other dim bulbs go off in the meantime though!
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Post by Ron Rich on Jul 23, 2020 18:27:44 GMT
Will do-- however I am thinking (EZ for you to do) that my power supply has failed -- Ron Rich
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Post by drkatz on Jul 23, 2020 18:59:38 GMT
Thanks, Norman! I didn't see your reply since I think yours went on to the next page. I'm only seeing two fuses in the power distribution box. And two on top of the amp. All of these fuses seem to be fine, unfortunately. I'll also note that my speaker overload light has never come on and looks like the filament is fine.
I'm having trouble understanding where I should be checking for voltage (sorry I'm not super well versed in electronics). I'm thinking I should be checking on the 12 pin output plug on the power distribution box, but I don't know what voltage to be looking for from which pins.
I'm not seeing any bad solder joints anywhere on the amp. I did go ahead and replace a few capacitors on the driver boards since I had the right values. Should I continue down that road of replacing all of the old caps on the board?
Sorry that was a TON of questions. Getting this jukebox working is consuming me.
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Post by jukenorman on Jul 23, 2020 19:13:27 GMT
Pins 1 and 5 on the red 6 pin plug carry the 46VAC - that's the power supply in to the amplifier. I don't know the pin orientation on the plug but the two wires are orange according to the amplifier schematic.
Norman.
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Post by drkatz on Jul 23, 2020 20:34:54 GMT
I'm not getting anything close to 46 VAC in ANY pin on the power supply box plug to the amp. Everything else in there looks OK. I haven't started pulling out components in the power supply to test. Would that be the next step?
There's a whole lot of wires in there to check. Am I correct in thinking that there is a power transformer specifically for the amp? Is there a way to test that?
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Post by jukenorman on Jul 23, 2020 21:28:59 GMT
You might not see 46 VAC unless you are checking across pins 1 & 5, because it may not be referenced to ground. Did you find two orange wires on the red plug? The schematic for the power supply is only on the large fold out sheet that comes with the manual, I'll have to see if I can find one similar to yours. I don't have any 460 documentation.
Norman.
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Post by jukenorman on Jul 24, 2020 10:08:39 GMT
To answer your earlier question, yes there is a dedicated transformer in the power supply for the amplifier. There is a circuit breaker on the primary winding. The secondary has a centre tapped winding 46-0-46 so I believe you should see 46V with respect to ground on both pins 1 & 5 of the red plug - contrary to my previous reply! The next iteration of Rock-Olas does not have a dedicated transformer for the amplifier (all very confusing).
Norman.
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Post by Ron Rich on Jul 24, 2020 12:03:50 GMT
Hi Norman,
Not "confusing"-- just Antique Apparatus in-ja-neer-ing ! Ron Rich
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Post by drkatz on Jul 24, 2020 18:57:30 GMT
Confusing, antique engineering; Tomayto, tomahto. Anyway, just got AC readings from the twelve pin connector on my power supply. This is what I'm getting 11.55v, ~0.02v, 0v, 26.5v 51.7v, 2.08v, ~0.5v, 0v 92.1v, ~0.1v, ~0v, 0v If that "grid" doesn't make sense, here's an album of each reading: imgur.com/a/Du7OkzcThe colors on these wires that go into that plug are as follows (following the same grid layout): orange with green stripe, blue with white, black, tan red w/yellow stripe, grayish, brown w/white, purple w/ yellow orange, blank space (no wire), black, pinkish orange The only one of these value that looks remotely close to the 46 VAC is the red wire @ 51.7 VAC Neal |
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Post by jukenorman on Jul 24, 2020 21:45:21 GMT
Hi Neal,
We seem to be a bit at cross purposes here - I am referring to the red 6 pin plug which carries power into the amplifier and I can now see that you are measuring on the 12 pin plug taking power out of the power supply. On the 12 pin plug that you are measuring, the 46 - 0 - 46 AC volts for the amplifier go out on pins 10, 11 & 12.
According to the power supply drawing, pin 1 is ground. Your bottom right reads 0V, could that be pin 1? In which case, are the three left-most pins 10, 11 & 12? From the mish mash of drawings that I have, I am unable to determine where the 0V (ie centre tap of the amplifier transformer) terminates - I strongly suspect that it goes to ground and that maybe you have lost that connection somehow?. It's interesting that you are measuring 92 volts on the bottom left hand pin (2 times 46). What do you get if you measure the top and bottom left-most pins with respect to the centre left pin?
Because I don't have a Rock-Ola of this vintage to check, I am probably getting close to the limit of the assistance that I can offer you.
Norman.
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Post by drkatz on Jul 25, 2020 2:50:11 GMT
Calling jukerocks. Are you able to get the readings from your power supply? I'm pretty sure you have the same jukebox as me. |
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Post by jukerocks on Jul 26, 2020 19:02:49 GMT
Yes. The readings I'd posted were at the 6-pin to the amp grounded inside. Same on both the 460 & 464.
Patrick
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Post by drkatz on Jul 27, 2020 13:41:08 GMT
Thanks! I'm not able to reproduce those values, or even get very close, so I'm hoping replacing the power supply will remedy that. A new (to me) one is in the mail, so fingers crossed! I'll update on here if it fixes anything.
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Post by Ron Rich on Jul 27, 2020 13:55:24 GMT
Good luck-- I hope you purchased that "new" PS from a reliable source, who assured you that it was good ! ( see our "off topic" "scams" post !) Ron Rich
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