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#147974 - 04/17/03 01:07 PM Recall of Thomson Home Entertainment Amplifiers
Webmaster Offline


Registered: 10/07/00
Posts: 3142
Loc: NY, USA
WASHINGTON, D.C. - In cooperation with the U.S. Consumer Product Safety Commission (CPSC), Thomson Inc., of Indianapolis, Ind., is voluntarily recalling about 50,000 home entertainment amplifiers. The amplifier can overheat due to a lack of ventilation, which can cause melting of the plastic front cover and pose a shock hazard to consumers.

Thomson has received 12 reports of the amplifiers overheating, some of which resulted in melting of the plastic front cover or faceplate. No injuries have been reported.
Click >> more info

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#147975 - 04/17/03 02:29 PM Re: Recall of Thomson Home Entertainment Amplifiers
SvenNYC Offline

Registered: 08/19/02
Posts: 1685
Loc: New York City
It's more than just an amplifier. It's a it is also probably subject to continous operation for hours on end.

I know these stereos run hot, but melting the faceplate? Thank goodness for my 20-year old Marantz and Harmann-Kardon radios!!

No wonder I don't trust anything with the RCA or GE nameplate anymore (both made Thomson Electronics).

I'm sure the fact that the designers trying squeeze more and more electronics into an ever-shrinking package has a lot to do with it.

#147976 - 04/19/03 03:59 AM Re: Recall of Thomson Home Entertainment Amplifiers
Trumpy Offline


Registered: 07/05/02
Posts: 8532
Loc: SI,New Zealand
I agree with you there, older is better!.
Also, we all know how consumers like to stack things on top of amps and other appliances like this, after putting them into a close fitting cabinet.
Let's face it, these days if you're not young, you're old - Red Green grin

#147977 - 04/19/03 02:15 PM Re: Recall of Thomson Home Entertainment Amplifiers
pauluk Offline

Registered: 08/11/01
Posts: 7693
Loc: Norfolk, England
I sometimes wonder how many people pay any attention to warnings about adequate ventilation for equipment. Stuff gets stacked up on top of each other, then something gets laid right across the top items completely blocking the ventilation slots.

Another problem these days is the ever-growing tendency to use the cheapest component possible. On a large production run, there's always been the requirement to do this to keep costs to a minimum (and therefore profits to a maximum), but the problem is that components are being much more generously rated than in the past.

Just compare the physical size of a 1/2-watt resistor now with a resistor of similar rating from 30 years ago.

#147978 - 04/20/03 03:25 PM Re: Recall of Thomson Home Entertainment Amplifiers
Trumpy Offline


Registered: 07/05/02
Posts: 8532
Loc: SI,New Zealand
I agree with you comments on component sizes, I always thought that heat dissipation was directly related to surface area, as far as resistors and heatsinks were concerned anyway.
It's no wonder Home Electronics break down so often these days.
Have you also noticed, that while equipment itself is getting smaller, so are the ventilation slots or they are non-existant?.
With some equipment I've seen recently, it's a wonder that they don't need a fan to suck all of the heat out.
Let's face it, these days if you're not young, you're old - Red Green grin

#147979 - 05/01/03 05:30 PM Re: Recall of Thomson Home Entertainment Amplifiers
R.Legg Offline
Junior Member

Registered: 05/18/01
Posts: 5
Here we go again.

If it's smaller than a breadbox or larger than a cigarette package, the average surface temperature rise of an unventillated box sitting on a flat surface, will be one degree Centigrade for every milliwatt/cm^2 of surface area,

With a plastic box, the temperature of the internal surface (ie the internal ambient air)will be higher.

With a cabinet that is intended to act as a loudspeaker enclosure,the ported vent introduced for sound quality reasons serves as an abominable air vent.

The idea is that a switching audio circuit can be made more efficient (ie smaller) than a linear one, but cost considerations can do two things - it will stick both amps in one speaker container and it will substitute linear amplifiers for the lowest-cost variant that must be stuffed in the same hardware.

Then you have to remember that linear cicuits tested at their ratings won't get as hot as the same circuits operated at a reduced output. A safety examiner might miss that nowadays.


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