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Electronics Repair (sci.electronics.repair) Discussion of repairing electronic equipment. Topics include requests for assistance, where to obtain servicing information and parts, techniques for diagnosis and repair, and annecdotes about success, failures and problems. |
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#1
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Does anyone know the voltages on the 3 secondaries
Main deck motor 12V but about 10.5V dc from the supply, nothing wrong with the ps and nothing wrong with the motor and its regulator. All that is left is the mains transformer. |
#2
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On Wed, 11 Mar 2009 15:22:56 -0000, "N_Cook"
wrote: Does anyone know the voltages on the 3 secondaries Main deck motor 12V but about 10.5V dc from the supply, nothing wrong with the ps and nothing wrong with the motor and its regulator. All that is left is the mains transformer. Personally I'd suspect the motor first. Have you checked the current draw by the motor? Sometimes as they age they draw more current. Q: is the trasnformer running hot? If it is that would indicate a problem (Shorted turns). |
#3
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PeterD wrote in message
... On Wed, 11 Mar 2009 15:22:56 -0000, "N_Cook" wrote: Does anyone know the voltages on the 3 secondaries Main deck motor 12V but about 10.5V dc from the supply, nothing wrong with the ps and nothing wrong with the motor and its regulator. All that is left is the mains transformer. Personally I'd suspect the motor first. Have you checked the current draw by the motor? Sometimes as they age they draw more current. Q: is the trasnformer running hot? If it is that would indicate a problem (Shorted turns). I happened to have a near exact salvaged motor to swap over , pinion is grub screw fixed, so easy. Maybe both hare wrong the same way. Much the same result of DC 12V and too slow deck drive. It maybe that the drivebelt is super critical but the dc over the motor is only about 12V with another belt, so loose, that the pinion slips under it. Transformer seems fine, no buzz or heat. -- Diverse Devices, Southampton, England electronic hints and repair briefs , schematics/manuals list on http://home.graffiti.net/diverse:graffiti.net/ |
#4
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PeterD wrote in message
... On Wed, 11 Mar 2009 15:22:56 -0000, "N_Cook" wrote: Does anyone know the voltages on the 3 secondaries Main deck motor 12V but about 10.5V dc from the supply, nothing wrong with the ps and nothing wrong with the motor and its regulator. All that is left is the mains transformer. Personally I'd suspect the motor first. Have you checked the current draw by the motor? Sometimes as they age they draw more current. Q: is the trasnformer running hot? If it is that would indicate a problem (Shorted turns). An attitude problem. Bench tested/loaded both motors laying horizontal but the Aiwa one does not like being upside down, as in actual useage, doh. -- Diverse Devices, Southampton, England electronic hints and repair briefs , schematics/manuals list on http://home.graffiti.net/diverse:graffiti.net/ |
#5
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N_Cook wrote:
Does anyone know the voltages on the 3 secondaries Main deck motor 12V but about 10.5V dc from the supply, nothing wrong with the ps and nothing wrong with the motor and its regulator. All that is left is the mains transformer. Supply reservoir capacitor open circuit? -- Adrian C |
#6
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N_Cook wrote:
Does anyone know the voltages on the 3 secondaries Main deck motor 12V but about 10.5V dc from the supply, nothing wrong with the ps and nothing wrong with the motor and its regulator. All that is left is the mains transformer. Nigel, For what it's worth, I'm looking at a diagram for an AD-6300U, dated December 1976. This is a US model, with only a 120V primary. It shows that the transformer has 3 secondaries, one of which is devoted to the motor. It has a half wave (single diode) rectifier, D503, and a 1000uf/16V capacitor, C506. It shows the voltage on the cap as 14.5V it also shows 2 switches, S6 and S7 in parallel between the cap and the motor, so either switch could power up the motor. Could you have badly corroded switch contacts that are causing a large voltage drop? What is the voltage with the motor disconnected? If you are measuring the 10.5V at the capacitor, then I'd say try replacing the diode and/or capacitor. Regards, Tim Schwartz Bristol Electronics |
#7
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Tim Schwartz wrote in message
... N_Cook wrote: Does anyone know the voltages on the 3 secondaries Main deck motor 12V but about 10.5V dc from the supply, nothing wrong with the ps and nothing wrong with the motor and its regulator. All that is left is the mains transformer. Nigel, For what it's worth, I'm looking at a diagram for an AD-6300U, dated December 1976. This is a US model, with only a 120V primary. It shows that the transformer has 3 secondaries, one of which is devoted to the motor. It has a half wave (single diode) rectifier, D503, and a 1000uf/16V capacitor, C506. It shows the voltage on the cap as 14.5V it also shows 2 switches, S6 and S7 in parallel between the cap and the motor, so either switch could power up the motor. Could you have badly corroded switch contacts that are causing a large voltage drop? What is the voltage with the motor disconnected? If you are measuring the 10.5V at the capacitor, then I'd say try replacing the diode and/or capacitor. Regards, Tim Schwartz Bristol Electronics Much the same, half wave, switches, cap that I repalced was 1000uF, 25V now 2000 uF. Switch contacts were the first thing I checked. No its a motor problem and very critical on drive band properties, the main one and the FF/REW one they both interact of course and only a narrow range of tensions allowable. 11V in play and FF/REW now and speed constant and upto speed. I had to convince myself it was a motor problem by connecting in 6volt ac at the motor fuse and it made no difference because of the NEC upc1003 inside the motor limiting current. I doubt these sorts of motors are available new these days. -- Diverse Devices, Southampton, England electronic hints and repair briefs , schematics/manuals list on http://home.graffiti.net/diverse:graffiti.net/ |
#8
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Tim Schwartz wrote in message
... N_Cook wrote: Does anyone know the voltages on the 3 secondaries Main deck motor 12V but about 10.5V dc from the supply, nothing wrong with the ps and nothing wrong with the motor and its regulator. All that is left is the mains transformer. Nigel, For what it's worth, I'm looking at a diagram for an AD-6300U, dated December 1976. This is a US model, with only a 120V primary. It shows that the transformer has 3 secondaries, one of which is devoted to the motor. It has a half wave (single diode) rectifier, D503, and a 1000uf/16V capacitor, C506. It shows the voltage on the cap as 14.5V it also shows 2 switches, S6 and S7 in parallel between the cap and the motor, so either switch could power up the motor. Could you have badly corroded switch contacts that are causing a large voltage drop? What is the voltage with the motor disconnected? If you are measuring the 10.5V at the capacitor, then I'd say try replacing the diode and/or capacitor. Regards, Tim Schwartz Bristol Electronics I checked rec and nothing except erase. Does the 6300 use 2 separate single in line rec/play changeover switch assemblies. The 6500 ones seem to be 10 pole change over , straight from pim 1 to 30 except 3 in the middle which don't switch over to anytrhing else , both L and R switches failed? the same which seems very odd for each to separately loose the same set of contacts . |
#9
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On Thu, 12 Mar 2009 12:26:32 -0000, "N_Cook" put
finger to keyboard and composed: Much the same, half wave, switches, cap that I repalced was 1000uF, 25V now 2000 uF. Switch contacts were the first thing I checked. No its a motor problem and very critical on drive band properties, the main one and the FF/REW one they both interact of course and only a narrow range of tensions allowable. 11V in play and FF/REW now and speed constant and upto speed. I had to convince myself it was a motor problem by connecting in 6volt ac at the motor fuse and it made no difference because of the NEC upc1003 inside the motor limiting current. I doubt these sorts of motors are available new these days. FWIW, I have an Aiwa AD6300 (not AD6500) which I could cannibalise for spares. I'm in Australia, though. - Franc Zabkar -- Please remove one 'i' from my address when replying by email. |
#10
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Must be some enthuiast who owns this one. Eded up desoldering a Rec/Play
slide switch. Alps make but instead of light horizontal wear on the static pins some were gouges, slightly arced . The sliding contact must have started fouling in the gouges then tipping up and opening out. Robbed some sliding contacts from a NOS one. Different make and design, so the sliding contacts now engage with a different part of the static pins. Regular 10 pole c/o ALPS 82-371-620-01 -- Diverse Devices, Southampton, England electronic hints and repair briefs , schematics/manuals list on http://home.graffiti.net/diverse:graffiti.net/ |
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