I have a 10 year old AV receiver that I opened to de-dust. I noticed that on
the heat sink there a black foam material running across the top length of
the heat sink. The foam looks like double-sided foam tape, but is sticky on
one side only.

I'm not sure what the intended purpose of this was, and if I should attempt
to repair/replace it with something else as it is cracking off.

I could use regular foam double-sided tape, but imagine that the heat sink
get very hot and the tape would get unsticky very quickly.

Any thoughts on why it would be there in the first place, and what to use to
replace it.

Some pics:
http://tinypic.com/r/2qvfs6q/5
http://tinypic.com/r/53pm61/5
http://tinypic.com/r/2wq60eo/5

Thanks

On Thu, 17 Oct 2013 09:08:51 -0400, "Zack" wrote:

I have a 10 year old AV receiver that I opened to de-dust. I noticed that on
the heat sink there a black foam material running across the top length of
the heat sink. The foam looks like double-sided foam tape, but is sticky on
one side only.

I'm not sure what the intended purpose of this was, and if I should attempt
to repair/replace it with something else as it is cracking off.

I could use regular foam double-sided tape, but imagine that the heat sink
get very hot and the tape would get unsticky very quickly.

Any thoughts on why it would be there in the first place, and what to use to
replace it.

Some pics:
http://tinypic.com/r/2qvfs6q/5
http://tinypic.com/r/53pm61/5
http://tinypic.com/r/2wq60eo/5

My guess(tm) is that it's to reduce or prevent vibration of the heat
sink in shipping. It's difficult to tell from your photo, but it
looks like the heat sink is only supported on the PCB end, with the
upper end floating free. Such a construction could cause the heatsink
to vibrate in shipping, and eventually break something on the PCB end.


--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

On 17/10/2013 14:08, Zack wrote:
I have a 10 year old AV receiver that I opened to de-dust. I noticed that on
the heat sink there a black foam material running across the top length of
the heat sink. The foam looks like double-sided foam tape, but is sticky on
one side only.

I'm not sure what the intended purpose of this was, and if I should attempt
to repair/replace it with something else as it is cracking off.

I could use regular foam double-sided tape, but imagine that the heat sink
get very hot and the tape would get unsticky very quickly.

Any thoughts on why it would be there in the first place, and what to use to
replace it.

Some pics:
http://tinypic.com/r/2qvfs6q/5
http://tinypic.com/r/53pm61/5
http://tinypic.com/r/2wq60eo/5

Thanks



If someone sat on the amp would the heatsink touch the casing?

On Thu, 17 Oct 2013 19:40:47 +0100, N_Cook wrote:

If someone sat on the amp would the heatsink touch the casing?

Yes, depending on who will be sitting on the amp:
https://www.google.com/search?tbm=isch&q=sumo
I don't think a little foam tape is going to help.
--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

"Zack" wrote:
I have a 10 year old AV receiver that I opened to de-dust. I noticed that on
the heat sink there a black foam material running across the top length of
the heat sink. The foam looks like double-sided foam tape, but is sticky on
one side only.

I'm not sure what the intended purpose of this was, and if I should attempt
to repair/replace it with something else as it is cracking off.

I could use regular foam double-sided tape, but imagine that the heat sink
get very hot and the tape would get unsticky very quickly.

Any thoughts on why it would be there in the first place, and what to use to
replace it.

Some pics:
http://tinypic.com/r/2qvfs6q/5
http://tinypic.com/r/53pm61/5
http://tinypic.com/r/2wq60eo/5

Thanks

If there was a fan, I could see it's use to block free flow.

Greg

"Zack" wrote in message
m...
I have a 10 year old AV receiver that I opened to de-dust. I noticed that
on
the heat sink there a black foam material running across the top length of
the heat sink. The foam looks like double-sided foam tape, but is sticky
on
one side only.

I'm not sure what the intended purpose of this was, and if I should
attempt
to repair/replace it with something else as it is cracking off.

I could use regular foam double-sided tape, but imagine that the heat sink
get very hot and the tape would get unsticky very quickly.

Any thoughts on why it would be there in the first place, and what to use
to
replace it.

Some pics:
http://tinypic.com/r/2qvfs6q/5
http://tinypic.com/r/53pm61/5
http://tinypic.com/r/2wq60eo/5

Thanks


Random stuff like this is by no means uncommon. Doubtless someone at the
factory thought it was a good idea for some reason, but I doubt that reason
is anything particularly significant or important. At the end of the day, if
it has been working fine for many years, irrespective of the condition of
the tape, I would just leave it alone. As to the heatsink getting 'very'
hot, it shouldn't, especially a large one like that, unless you are
thrashing the poor thing unrealistically hard. If you feel that you really
must replace it, I would certainly try sticky-backed draught excluder tape
for a start.

Alternatively, find a service manual online, and look at the exploded
diagram for that area. It may well have the tape detailed in the parts list
as to what it is made of, and its part designator might even give a clue as
to what it's there for. Sony, for instance, tend to detail every last item
in their bits of kit

Arfa

"Jeff Liebermann" wrote in message
...
On Thu, 17 Oct 2013 09:08:51 -0400, "Zack" wrote:

I have a 10 year old AV receiver that I opened to de-dust. I noticed that
on
the heat sink there a black foam material running across the top length of
the heat sink. The foam looks like double-sided foam tape, but is sticky
on
one side only.

I'm not sure what the intended purpose of this was, and if I should
attempt
to repair/replace it with something else as it is cracking off.

I could use regular foam double-sided tape, but imagine that the heat sink
get very hot and the tape would get unsticky very quickly.

Any thoughts on why it would be there in the first place, and what to use
to
replace it.

Some pics:
http://tinypic.com/r/2qvfs6q/5
http://tinypic.com/r/53pm61/5
http://tinypic.com/r/2wq60eo/5

My guess(tm) is that it's to reduce or prevent vibration of the heat
sink in shipping. It's difficult to tell from your photo, but it
looks like the heat sink is only supported on the PCB end, with the
upper end floating free. Such a construction could cause the heatsink
to vibrate in shipping, and eventually break something on the PCB end.


--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

Thanks for your reply.

I know it is hard to see from the pic but the tape is not on the top face of
the HS, it is actually on the HS fins with the edge of the tape pointing up
and down. ie the sticky part of the tape is on the fins

"N_Cook" wrote in message
...
On 17/10/2013 14:08, Zack wrote:
I have a 10 year old AV receiver that I opened to de-dust. I noticed that
on
the heat sink there a black foam material running across the top length
of
the heat sink. The foam looks like double-sided foam tape, but is sticky
on
one side only.

I'm not sure what the intended purpose of this was, and if I should
attempt
to repair/replace it with something else as it is cracking off.

I could use regular foam double-sided tape, but imagine that the heat
sink
get very hot and the tape would get unsticky very quickly.

Any thoughts on why it would be there in the first place, and what to use
to
replace it.

Some pics:
http://tinypic.com/r/2qvfs6q/5
http://tinypic.com/r/53pm61/5
http://tinypic.com/r/2wq60eo/5

Thanks



If someone sat on the amp would the heatsink touch the casing?

Please see my post to Jeff. You are misinterpreting the pic (know is a lousy
picture). Actually picture 2 shows a better close up (
http://tinypic.com/r/53pm61/5)

"gregz" wrote in message
...
"Zack" wrote:
I have a 10 year old AV receiver that I opened to de-dust. I noticed that
on
the heat sink there a black foam material running across the top length
of
the heat sink. The foam looks like double-sided foam tape, but is sticky
on
one side only.

I'm not sure what the intended purpose of this was, and if I should
attempt
to repair/replace it with something else as it is cracking off.

I could use regular foam double-sided tape, but imagine that the heat
sink
get very hot and the tape would get unsticky very quickly.

Any thoughts on why it would be there in the first place, and what to use
to
replace it.

Some pics:
http://tinypic.com/r/2qvfs6q/5
http://tinypic.com/r/53pm61/5
http://tinypic.com/r/2wq60eo/5

Thanks

If there was a fan, I could see it's use to block free flow.

Greg

Greg, There is a fan.

If you look at the first picture, there is a black hood to the right of my
text. Under the hood is a fan. It doesn't look like the fan actually blows
into the heat sink as the other side of the fan appear closed (unless the
holes are on the bottom face, which I cant see).

Do you think I should try to replace the tape with something? what?

"Zack" wrote:
"gregz" wrote in message
...
"Zack" wrote:
I have a 10 year old AV receiver that I opened to de-dust. I noticed that
on
the heat sink there a black foam material running across the top length
of
the heat sink. The foam looks like double-sided foam tape, but is sticky
on
one side only.

I'm not sure what the intended purpose of this was, and if I should
attempt
to repair/replace it with something else as it is cracking off.

I could use regular foam double-sided tape, but imagine that the heat
sink
get very hot and the tape would get unsticky very quickly.

Any thoughts on why it would be there in the first place, and what to use
to
replace it.

Some pics:
http://tinypic.com/r/2qvfs6q/5
http://tinypic.com/r/53pm61/5
http://tinypic.com/r/2wq60eo/5

Thanks

If there was a fan, I could see it's use to block free flow.

Greg

Greg, There is a fan.

If you look at the first picture, there is a black hood to the right of my
text. Under the hood is a fan. It doesn't look like the fan actually blows
into the heat sink as the other side of the fan appear closed (unless the
holes are on the bottom face, which I cant see).

Do you think I should try to replace the tape with something? what?

Should not get too hot. Some more weather-stripping or pipe insulation.

Greg

On Fri, 18 Oct 2013 15:20:02 -0400, "Zack" wrote:

I know it is hard to see from the pic but the tape is not on the top face of
the HS, it is actually on the HS fins with the edge of the tape pointing up
and down. ie the sticky part of the tape is on the fins

It's difficult to determine if the tape was jammed in between the heat
sink and the top cover from the photos. If it was, it might be a
transport vibration damper. If not, as you describe here, then
perhaps the tape was improperly installed at the factory?

Drivel: I once owned a 1970 Land Rover Series 2A. A feature of the
engine was a length of sheet metal between the spark plugs and the
firewall. As far as I could determine, it served no useful purpose
and was perpetually in the way of doing normal engine maintenance. One
day, I decided to remove it. Nothing happened until I hit about 50
mph on the freeway, when I heard a loud low pitched whine coming from
under the hood. The wind had turned the engine compartment into a
giant whistle. Beware of such non-obvious design features when
removing tape, gum, goo, and other obvious band-aids.


--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

Jeff Liebermann wrote:

On Thu, 17 Oct 2013 19:40:47 +0100, N_Cook wrote:

If someone sat on the amp would the heatsink touch the casing?

Yes, depending on who will be sitting on the amp:
https://www.google.com/search?tbm=isch&q=sumo
I don't think a little foam tape is going to help.

Think about the casing flexing down just a bit. Possibly when you place
another component on top of this one. Add some vibration and the heat sink
will buzz against the case. This is probably what the foam is for.

--
Paul Hovnanian
------------------------------------------------------------------
Ubuntu - Bantu for "I don't know how to configure Debian."

You know I am just going to throw this out there, could be it or could just be a blow of smoke but....

What if maybe the heatsink fins exhibited a resonance at some audible frequency ? I mean like they found that under certain conditions the loud audio would excite the them to vibrating at say 6 Khz ?

Stranger **** has happened. Remember I'm the guy who had to adjust the vertical height to keep a TV from turning all red. I **** you not. For the puzzled : It had to do with AKB. Details on request.

"Paul Hovnanian P.E." wrote in message
...
Jeff Liebermann wrote:

On Thu, 17 Oct 2013 19:40:47 +0100, N_Cook wrote:

If someone sat on the amp would the heatsink touch the casing?

Yes, depending on who will be sitting on the amp:
https://www.google.com/search?tbm=isch&q=sumo
I don't think a little foam tape is going to help.

Think about the casing flexing down just a bit. Possibly when you place
another component on top of this one. Add some vibration and the heat sink
will buzz against the case. This is probably what the foam is for.

--
Paul Hovnanian

I, like others, originally thought this might be the case, but as the OP has
gone to pains to explain, the foam is not on top of the heatsink. It is at
90 deg to that situation, stuck to the vertical fins ...

Arfa

On Fri, 25 Oct 2013 18:27:14 +0100, "Arfa Daily"
wrote:
I, like others, originally thought this might be the case, but as the OP has
gone to pains to explain, the foam is not on top of the heatsink. It is at
90 deg to that situation, stuck to the vertical fins ...

Arfa

(Never attribute to design that which can best be explained by sloppy
assembly).

Maybe the foam tape is there to protect the heat sinks during
production and someone forgot to remove the tape? Or, it could be
there to protect the workers from the sharp edges? Or, maybe someone
just installed the tape in the wrong location?

Drivel: One of the radios I worked on had a crystal oven that was
thermally insulated with some styrofoam. At least once a month, we
would receive a radio back for repair, with the styrofoam removed.
When asked, the customer or dealer would usually mumble something
about the styrofoam being packing material.

--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

"(Never attribute to design that which can best be explained by sloppy
assembly)"

Thou hast coined another Leibermannism. What number is this one ? :-)

On Sat, 26 Oct 2013 09:53:50 -0700 (PDT), wrote:

"(Never attribute to design that which can best be explained by sloppy
assembly)"

Thou hast coined another Leibermannism. What number is this one ? :-)

X.XXVI.MMXIII

How Usenet really works:
http://802.11junk.com/jeffl/crud/genesis.txt

--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558