Technics receiver overload

Archived from groups: rec.audio.tech (More info?)

"Don Phillipson" <d.phillipson@ttrryytteell.com> wrote in message
news:iQKRd.548$MJ.2871@newscontent-01.sprint.ca...
> Now three or four years old, the Technics
> SA AX540 radio receiver displays "Overload"
> on its panel after a couple of hours' use.
> The manual says likely causes are cross-
> connected speaker wires (unlikely) or overheating.
> It also says the unit is irreparable except by a
> Technics shop.
>
> Raising the receiver half an inch on blocks
> seems to prevent this Overload. But should
> I be shopping for a new unit?

It sounds to me like your receiver is poorly ventilated. Couple poor
ventilation with loud music, and you have a formula for "overload."
Disconnect the speakers and see if you can get it to go into overload. If
you can, then there's something wrong with the receiver.

No, it isn't necessarily the case that you can't repair the receiver, but
I'm sure Technics would rather you not try.

Norm Strong

Archived from groups: rec.audio.tech (More info?)

"Don Phillipson" <d.phillipson@ttrryytteell.com> wrote in message
news:iQKRd.548$MJ.2871@newscontent-01.sprint.ca...

> Now three or four years old, the Technics
> SA AX540 radio receiver displays "Overload"
> on its panel after a couple of hours' use.
> The manual says likely causes are cross-
> connected speaker wires (unlikely) or overheating.

Thanks both for comments.
1. The unit was clean and not dusty inside -- but
seems poorly ventilated. Raising the receiver
(enclosed) on blocks led to another Overload
within 2 hours.
2. This unit has two sets of loudspeaker connectors.
So I swapped to the B speakers and have now
run for nearly five hours with the cover off, (Saturday
Metropolitan opera, our usual fare) with no Overload
yet. So I just put the cover back too for another trial.

All this is guesswork i.e. nothing visible suggests
how the A speaker wiring might degrade in four
years' use. But ventilation looks poor. (Maybe
I shall cut extra ports in the case.)

--
Don Phillipson
Carlsbad Springs
(Ottawa, Canada)

Archived from groups: rec.audio.tech (More info?)

"Don Phillipson" <d.phillipson@ttrryytteell.com> wrote in message
news:iQKRd.548$MJ.2871@newscontent-01.sprint.ca...
> Now three or four years old, the Technics
> SA AX540 radio receiver displays "Overload"
> on its panel after a couple of hours' use.
> The manual says likely causes are cross-
> connected speaker wires (unlikely) or overheating.
> It also says the unit is irreparable except by a
> Technics shop.
> Raising the receiver half an inch on blocks
> seems to prevent this Overload. But should
> I be shopping for a new unit?

I'd pull it out and take a peek inside.. if it's really dusty in there that
might account for the overheating, especially if it's got a fan that might
be clogged or not spinning when it's supposed to.

Archived from groups: rec.audio.tech (More info?)

"Don Phillipson" <d.phillipson@ttrryytteell.com> wrote in message
news:rqSRd.621$MJ.3181@newscontent-01.sprint.ca...
> "Don Phillipson" <d.phillipson@ttrryytteell.com> wrote in message
> news:iQKRd.548$MJ.2871@newscontent-01.sprint.ca...
>
>> Now three or four years old, the Technics
>> SA AX540 radio receiver displays "Overload"
>> on its panel after a couple of hours' use.
>> The manual says likely causes are cross-
>> connected speaker wires (unlikely) or overheating.
>
> Thanks both for comments.
> 1. The unit was clean and not dusty inside -- but
> seems poorly ventilated. Raising the receiver
> (enclosed) on blocks led to another Overload
> within 2 hours.
> 2. This unit has two sets of loudspeaker connectors.
> So I swapped to the B speakers and have now
> run for nearly five hours with the cover off, (Saturday
> Metropolitan opera, our usual fare) with no Overload
> yet. So I just put the cover back too for another trial.
>
> All this is guesswork i.e. nothing visible suggests
> how the A speaker wiring might degrade in four
> years' use. But ventilation looks poor. (Maybe
> I shall cut extra ports in the case.)
>
> --
> Don Phillipson
> Carlsbad Springs
> (Ottawa, Canada)
>
>
>
Technics models are sort of notorious for bad solder connections, especially
at the output IC's and regulator transistors.

Mark Z.

Archived from groups: rec.audio.tech (More info?)

"Mark D. Zacharias" <mzacharias@yis.us> wrote in message
news:37qeriF4mn75fU1@individual.net...

> Technics models are sort of notorious for bad solder connections,
especially
> at the output IC's and regulator transistors.

Thanks for this because I shall have another
look with a magnifying glass.
Symptoms:
After years of OK use, sudden Overload displayed
I removed the cover and moved speaker connections
from the A to the B pair (cf. manual reference to
shorted speaker leads as a cause of Overload,
besides overheating.)

With cover removed, ran OK 6 hours or more
With cover replaced but not screwed, ran OK
Refastening cover, two back panel screws OK,
but as soon as I attached the first right side
panel screws (two each side) I got Overload again.
I removed this screw and the receiver ran normally.
I plan next to test the other 3 side panel screws.
--
Don Phillipson
Carlsbad Springs
(Ottawa, Canada)