Aiwa AD6500 cassette deck, 1975

[N_Cook]

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.

 

[PeterD]

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).

 

[N_Cook]

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.

 

[N_Cook]

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.

 

[Adrian C]

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?

 

[Tim Schwartz]

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

 

[N_Cook]

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.

 

[N_Cook]

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 .

 

[Franc Zabkar]

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

 

[N_Cook]

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