Cracking open a Galaxy Audio PA amp

[Jamie]

David Nebenzahl wrote:

On 9/15/2010 9:52 AM William Sommerwerck spake thus:

This product appears to be the pro-audio equivalent of most remote
controls.

I'm sure most people in this group have noticed how remote controls are
generally held together with screws /and/ near-unreleasable tabs. I've
never
understood why both are needed.


No, it's not, and you're misunderstanding the packaging here.

There's a diecast metal front panel which covers the entire front of the
unit, with a deeply set grille for the speaker. Six screws attach the
metal panel to the plastic cabinet.

The plastic cabinet is ONE PIECE, totally seamless, covering the
remaining 5 sides. So it's not a clamshell like most remotes or
similarly packaged electronics.


it most likely has a sealant between the front and plastic case to

prevent vibration at the seem, which is common with that type of
construction.. These things will stick like mild glue..

With the screws half way, wrap the unit in a soft wrap of some kind
like foam rubber so you don't scratch it, rest it on a pillow and use
something like a piece of wood to hit lightly against the screws that
are half way out.. The shock should push on the plastic behind and break
the bond!.

 

[Arfa Daily]

"Jamie" <jamie_ka1lpa_not_valid_after_ka1lpa_@charter.net> wrote in message
news:Rwcko.4403$FK1.2169@newsfe21.iad...

David Nebenzahl wrote:

On 9/15/2010 9:52 AM William Sommerwerck spake thus:

This product appears to be the pro-audio equivalent of most remote
controls.

I'm sure most people in this group have noticed how remote controls are
generally held together with screws /and/ near-unreleasable tabs. I've
never
understood why both are needed.


No, it's not, and you're misunderstanding the packaging here.

There's a diecast metal front panel which covers the entire front of the
unit, with a deeply set grille for the speaker. Six screws attach the
metal panel to the plastic cabinet.

The plastic cabinet is ONE PIECE, totally seamless, covering the
remaining 5 sides. So it's not a clamshell like most remotes or similarly
packaged electronics.


it most likely has a sealant between the front and plastic case to
prevent vibration at the seem, which is common with that type of
construction.. These things will stick like mild glue..

With the screws half way, wrap the unit in a soft wrap of some kind
like foam rubber so you don't scratch it, rest it on a pillow and use
something like a piece of wood to hit lightly against the screws that are
half way out.. The shock should push on the plastic behind and break
the bond!.

Ha! I was just about to come in with exactly the same observation, and you
beat me to it ! Quite a few of these powered speakers follow that general
style of construction, and it's common for something like the self adhesive
draught excluder foam strip that you fit around door and window frames, to
be used to form an airtight seal between the ally casting and the heavy
plastic case. It's not uncommon for this stuff to stick like a bitch when
it's been clamped up in that joint for a few years. If there genuinely is
just the six screws holding the front to the case, then likely as not, the
answer is just going to be brute force. Is there even the tiniest gap that
you could perhaps get something like a wide wood chisel into to see if you
can spring the plastic away from the metal a little ?

Arfa

 

[thanatoid]

"William Sommerwerck" <grizzledgeezer@comcast.net> wrote in
news:i6r02h$b71$1@news.eternal-september.org:

I'm sure most people in this group have noticed how
remote controls are generally held together with screws
/and/ near- unreleasable tabs. I've never understood why
both are needed.

No, it's not, and you're misunderstanding the packaging
here.

My point was about the /philosophy/ of the packaging. Why
belts+suspenders, when only one is needed?

Because an average remote gets dropped at least a few times a
week (my statistics), and is occasionally thrown at various
inanimate objects and assorted life forms.


--
"Anytime I hear the word "culture", I reach for my iPad."
- 21st Century Humanoid

 

[thanatoid]

"William Sommerwerck" <grizzledgeezer@comcast.net> wrote in
news:i6rkjd$uaa$1@news.eternal-september.org:

"thanatoid"

What a handle -- "the form of death".

Wow, I certainly DO appreciate you explaining it to me!

Sigh.


--
"Anytime I hear the word "culture", I reach for my iPad."
- 21st Century Humanoid

 

[Arfa Daily]

"Michael A. Terrell" <mike.terrell@earthlink.net> wrote in message
news:W-CdnYkpfYV8rQzRnZ2dnUVZ_rKknZ2d@earthlink.com...

Arfa Daily wrote:

"Michael A. Terrell" <mike.terrell@earthlink.net> wrote in message
news:BNCdnXxrdILq2Q3RnZ2dnUVZ_uadnZ2d@earthlink.com...

David Nebenzahl wrote:

I inherited a repair job that I can't get started because I can't get
the damn amp open.

It's a Galaxy Audio Core PA5X140 all-in-one PA. It's a tough little
unit, with a die-cast metal chassis set into a thick rugged plastic
(polypropylene?) case, that can sit on top of a mike stand. Similar to
this one: http://galaxyaudio.com/MSPA.jsp. The front of the chassis
has
6 screws into the case, and there's one on the back I removed, but I
still can't get the chassis out of the case. I tried prying the case,
thinking there might be some cast-in lugs I could open, but no luck,
and
I didn't want to risk chewing up the edge of the case.

Does anyone have any idea how to open up this unit?


At least no one has suggested a Plsma Cutter! ;-)


Nah! "Angle grinder" as they always say over on uk.d-i-y


Angle grinders are for amateurs and wimps. It takes a real prow to
cut something open with a plasma cutter and still have anything left to
repair.

It's a standing joke on that group Michael. "Angle grinder" is the 'silly'
answer when anyone asks for instance how to dismantle a ceramic cartridge
shower valve to clean it, or anything referring to a 'delicate' job. British
humour, and all that ...

Arfa

 

[Arfa Daily]

"Michael A. Terrell" <mike.terrell@earthlink.net> wrote in message
news:W-CdnYkpfYV8rQzRnZ2dnUVZ_rKknZ2d@earthlink.com...

Arfa Daily wrote:

"Michael A. Terrell" <mike.terrell@earthlink.net> wrote in message
news:BNCdnXxrdILq2Q3RnZ2dnUVZ_uadnZ2d@earthlink.com...

David Nebenzahl wrote:

I inherited a repair job that I can't get started because I can't get
the damn amp open.

It's a Galaxy Audio Core PA5X140 all-in-one PA. It's a tough little
unit, with a die-cast metal chassis set into a thick rugged plastic
(polypropylene?) case, that can sit on top of a mike stand. Similar to
this one: http://galaxyaudio.com/MSPA.jsp. The front of the chassis
has
6 screws into the case, and there's one on the back I removed, but I
still can't get the chassis out of the case. I tried prying the case,
thinking there might be some cast-in lugs I could open, but no luck,
and
I didn't want to risk chewing up the edge of the case.

Does anyone have any idea how to open up this unit?


At least no one has suggested a Plsma Cutter! ;-)


Nah! "Angle grinder" as they always say over on uk.d-i-y


Angle grinders are for amateurs and wimps. It takes a real prow to
cut something open with a plasma cutter and still have anything left to
repair.

It's a standing joke on that group Michael. "Angle grinder" is the 'silly'
answer when anyone asks for instance how to dismantle a ceramic cartridge
shower valve to clean it, or anything referring to a 'delicate' job. British
humour, and all that ...

Arfa

 

[William Sommerwerck]

"thanatoid"
What a handle -- "the form of death".

Wow, I certainly DO appreciate you explaining
it to me! Sigh.

I wasn't explaining it... I was acknowledging it. Clever.

 

[David Nebenzahl]

On 9/15/2010 12:51 PM bob u spake thus:

On 9/13/2010 12:32 AM, David Nebenzahl wrote:

I inherited a repair job that I can't get started because I can't
get the damn amp open.

It's a Galaxy Audio Core PA5X140 all-in-one PA. It's a tough little
unit, with a die-cast metal chassis set into a thick rugged
plastic (polypropylene?) case, that can sit on top of a mike stand.
Similar to this one: http://galaxyaudio.com/MSPA.jsp. The front of
the chassis has 6 screws into the case, and there's one on the back
I removed, but I still can't get the chassis out of the case. I
tried prying the case, thinking there might be some cast-in lugs I
could open, but no luck, and I didn't want to risk chewing up the
edge of the case.

Does anyone have any idea how to open up this unit?

I have a Core PA5X140 hot spot sitting in front of me. single 5"
speaker with amp built in. It really did not want to open either. It
has 6 screws on the front. a screw on the back. On this unit, there
are 1/4" phone jacks on the rear. These are connected to the internal
circuit board. SO, the lock nuts MUST be taken off the phone jacks
before you start the removal process.

On this one, the front face is inset down into the rear shell. My guess
is stictation or such is a factor. First on this unit, i gently pried
around the deal with a razer blade. Then i used a very small flat blade
screw driver to try to break loose the case from the front. Then i kind
of beat on it to see if gravity would help it separate (face down). I
eventually got it apart, but it did not want to easily separate.

Thanks for the first and only really helpful reply in this whole damn
thread.

You, sir, are a gentleman and a scholar. Sure enough, removing the nut
from the phone jack allowed the whole unit to slip rather easily out of
the case (I used a heavy knife blade betwixt the case and chassis to
start it).

The amp appears to be fine; there's either a problem with the XLR mike
input jack, or with the mike cable we were using. (Can't test because I
have no XLR plugs.)

Thanks again.


--
The fashion in killing has an insouciant, flirty style this spring,
with the flaunting of well-defined muscle, wrapped in flags.

- Comment from an article on Antiwar.com (http://antiwar.com)

 

[David Nebenzahl]

On 9/15/2010 1:03 PM Ron Weston spake thus:

There's a diecast metal front panel which covers the entire front
of the unit, with a deeply set grille for the speaker. Six screws
attach the metal panel to the plastic cabinet.

The plastic cabinet is ONE PIECE, totally seamless, covering the
remaining 5 sides. So it's not a clamshell like most remotes or
similarly packaged electronics.

Many years ago, I had to take apart a Philbrick K2-XA (those of you
old enough to remember this op-amp will realize how long ago). I
couldn't figure it out and called the factory. One of the engineers
told me the plastic case came in two halves and they were glued
together at the factory. The cases were so cheap that when a unit came
back for repair the case was split with a chisel, and after the repair
was complete a new case was glued on.

Heh; I'm totally not familiar with this device (almost old enough to be,
though), so when reading this I had visions of splitting open a 14-pin
DIP with a chisel, fixing it and gluing it back together.

Now *that* would be some repair.


--
The fashion in killing has an insouciant, flirty style this spring,
with the flaunting of well-defined muscle, wrapped in flags.

- Comment from an article on Antiwar.com (http://antiwar.com)

 

[Smitty Two]

In article <4c91a6a6$0$2405$822641b3@news.adtechcomputers.com>,
David Nebenzahl <nobody@but.us.chickens> wrote:

Sure enough, removing the nut
from the phone jack allowed the whole unit to slip rather easily out of
the case

Sheesh. You "shoulda" known enough to do that, at least. Good grief.

 

[N_Cook]

Arfa Daily <arfa.daily@ntlworld.com> wrote in message
news:c6eko.4111$vf.2909@newsfe18.ams2...

"Jamie" <jamie_ka1lpa_not_valid_after_ka1lpa_@charter.net> wrote in
message
news:Rwcko.4403$FK1.2169@newsfe21.iad...
David Nebenzahl wrote:

On 9/15/2010 9:52 AM William Sommerwerck spake thus:

This product appears to be the pro-audio equivalent of most remote
controls.

I'm sure most people in this group have noticed how remote controls
are
generally held together with screws /and/ near-unreleasable tabs. I've
never
understood why both are needed.


No, it's not, and you're misunderstanding the packaging here.

There's a diecast metal front panel which covers the entire front of
the
unit, with a deeply set grille for the speaker. Six screws attach the
metal panel to the plastic cabinet.

The plastic cabinet is ONE PIECE, totally seamless, covering the
remaining 5 sides. So it's not a clamshell like most remotes or
similarly
packaged electronics.


it most likely has a sealant between the front and plastic case to
prevent vibration at the seem, which is common with that type of
construction.. These things will stick like mild glue..

With the screws half way, wrap the unit in a soft wrap of some kind
like foam rubber so you don't scratch it, rest it on a pillow and use
something like a piece of wood to hit lightly against the screws that
are
half way out.. The shock should push on the plastic behind and break
the bond!.



Ha! I was just about to come in with exactly the same observation, and you
beat me to it ! Quite a few of these powered speakers follow that general
style of construction, and it's common for something like the self
adhesive
draught excluder foam strip that you fit around door and window frames, to
be used to form an airtight seal between the ally casting and the heavy
plastic case. It's not uncommon for this stuff to stick like a bitch when
it's been clamped up in that joint for a few years. If there genuinely is
just the six screws holding the front to the case, then likely as not, the
answer is just going to be brute force. Is there even the tiniest gap that
you could perhaps get something like a wide wood chisel into to see if you
can spring the plastic away from the metal a little ?

Arfa

The allied problem (Mackie powered speakers particularly) is long lazy
thread screws jammed into the plastic close to the point of shearing if
undoing them. I made a heated long shaft screwdriver for this, soldering
iron heater slid over the shaft.

 

[Arfa Daily]

"Smitty Two" <prestwhich@earthlink.net> wrote in message
newsrestwhich-8F29A8.22355915092010@news.eternal-september.org...

In article <4c91a6a6$0$2405$822641b3@news.adtechcomputers.com>,
David Nebenzahl <nobody@but.us.chickens> wrote:

Sure enough, removing the nut
from the phone jack allowed the whole unit to slip rather easily out of
the case

Sheesh. You "shoulda" known enough to do that, at least. Good grief.

Hmmm. I agree that is a little fundamental. I thought we were looking at a
'real' puzzle here ... And without an XLR balanced / unbalanced signal
source, how can you test properly, without making possibly unfounded guesses
about the service condition of the mic or its lead or the socket on this
amp. I would have thought that this sort of test would be fundamental before
wasting time trying to rip it all apart. It is in my workshop anyway.

Arfa

 

[bob u]

On 9/16/2010 3:30 AM, Arfa Daily wrote:

"Smitty Two" <prestwhich@earthlink.net> wrote in message
newsrestwhich-8F29A8.22355915092010@news.eternal-september.org...
In article <4c91a6a6$0$2405$822641b3@news.adtechcomputers.com>,
David Nebenzahl <nobody@but.us.chickens> wrote:

Sure enough, removing the nut
from the phone jack allowed the whole unit to slip rather easily out of
the case

Sheesh. You "shoulda" known enough to do that, at least. Good grief.

Its not really self evident that the jack is connected to the PC board.
When i took mine apart, i certainly did NOT think it was that way. I
eventually figured it out, but it took a while. i assumed it was just
a raw jack connected with loose wires to the amplifier.

bob

 

[William Sommerwerck]

Sure enough, removing the nut from the phone jack
allowed the whole unit to slip rather easily out of
the case

Sheesh. You "shoulda" known enough to do that,
at least. Good grief.

Its not really self evident that the jack is connected to
the PC board. When I took mine apart, I certainly did
NOT think it was that way. I eventually figured it out,
but it took a while. I assumed it was just a raw jack
connected with loose wires to the amplifier.

This sort of assembly is not that uncommon, as it reduces manufacturing
costs. It also makes testing the amplifier a bit easier. I've seen expensive
equipment that did the same thing, making the device virtually
unassembleable.

 

[Michael A. Terrell]

Arfa Daily wrote:

"Michael A. Terrell" <mike.terrell@earthlink.net> wrote in message
news:W-CdnYkpfYV8rQzRnZ2dnUVZ_rKknZ2d@earthlink.com...

Arfa Daily wrote:

"Michael A. Terrell" <mike.terrell@earthlink.net> wrote in message
news:BNCdnXxrdILq2Q3RnZ2dnUVZ_uadnZ2d@earthlink.com...

David Nebenzahl wrote:

I inherited a repair job that I can't get started because I can't get
the damn amp open.

It's a Galaxy Audio Core PA5X140 all-in-one PA. It's a tough little
unit, with a die-cast metal chassis set into a thick rugged plastic
(polypropylene?) case, that can sit on top of a mike stand. Similar to
this one: http://galaxyaudio.com/MSPA.jsp. The front of the chassis
has
6 screws into the case, and there's one on the back I removed, but I
still can't get the chassis out of the case. I tried prying the case,
thinking there might be some cast-in lugs I could open, but no luck,
and
I didn't want to risk chewing up the edge of the case.

Does anyone have any idea how to open up this unit?


At least no one has suggested a Plsma Cutter! ;-)


Nah! "Angle grinder" as they always say over on uk.d-i-y


Angle grinders are for amateurs and wimps. It takes a real prow to
cut something open with a plasma cutter and still have anything left to
repair.



It's a standing joke on that group Michael. "Angle grinder" is the 'silly'
answer when anyone asks for instance how to dismantle a ceramic cartridge
shower valve to clean it, or anything referring to a 'delicate' job. British
humour, and all that ...

And you still don't get American humor. ;-)


--
Politicians should only get paid if the budget is balanced, and there is
enough left over to pay them.

 

[bob u]

On 9/16/2010 7:19 AM, William Sommerwerck wrote:

Sure enough, removing the nut from the phone jack
allowed the whole unit to slip rather easily out of
the case

Sheesh. You "shoulda" known enough to do that,
at least. Good grief.

Its not really self evident that the jack is connected to
the PC board. When I took mine apart, I certainly did
NOT think it was that way. I eventually figured it out,
but it took a while. I assumed it was just a raw jack
connected with loose wires to the amplifier.

This sort of assembly is not that uncommon, as it reduces manufacturing
costs. It also makes testing the amplifier a bit easier. I've seen expensive
equipment that did the same thing, making the device virtually
unassembleable.

Its always a challenge these days to get apart some modern
"Unfixable"electronics. They really don't want you to fix them or
open them up. I sometimes get LCD monitors with issues that i
try to fix. Its always a game to figure out where on the case
the latches are on the clam shell and to pry and not bugger up
the case too much. I usually get them apart, but sometimes
there are "battle scars" in the process.

Even some remote controls are not the easiest things to open up.
I solved that by just giving them to my wife. She gets mad
and throws them at me and they mysteriously open up in parts...


the real fun is trying to get a power supply or such apart that
is spot welded together or glued. Thats more of a 50/50 deal
if you can get it apart without destroying it.

I like a good joke as much as anyone else. But when someone ask for help
and is maybe not a expert at least cut the guy some slack. Give an
answer and them make the smart comments.

bob

 

[Arny Krueger]

"Smitty Two" <prestwhich@earthlink.net> wrote in message
newsrestwhich-8F29A8.22355915092010@news.eternal-september.org

In article
4c91a6a6$0$2405$822641b3@news.adtechcomputers.com>,
David Nebenzahl <nobody@but.us.chickens> wrote:

Sure enough, removing the nut
from the phone jack allowed the whole unit to slip
rather easily out of the case

Sheesh. You "shoulda" known enough to do that, at least.
Good grief.

I feel stupid for not suggesting removing the nuts on the phone jacks. I've
seen this done sooooo many times.

I can't remember the last time I saw a phone jack that *wasn't* soldered to
a circuit card.

 

[Meat Plow]

On Wed, 15 Sep 2010 22:35:59 -0700, Smitty Two wrote:

In article <4c91a6a6$0$2405$822641b3@news.adtechcomputers.com>,
David Nebenzahl <nobody@but.us.chickens> wrote:

Sure enough, removing the nut
from the phone jack allowed the whole unit to slip rather easily out of
the case

Sheesh. You "shoulda" known enough to do that, at least. Good grief.

Yeah no kidding. <boggle>



--
Live Fast, Die Young and Leave a Pretty Corpse

 

[William Sommerwerck]

Not that clever, really. I was very depressed and suicidal for
most of my life. Recently I have been feeling better, but that's
another subject.

Welcome to the club. I have a very morbid personality. The German Requiem --
especially "All flesh is as grass" -- is my idea of light, frothy music. The
compensation is that I have a terrific sense of humor, which seems to go
with chronic depression -- qv, Brahms and Lincoln.

I would never try to talk someone out of their depression. There's often a
good reason for it, and drugs don't solve the problem.

 

[Ron]

On 16/09/2010 16:15, thanatoid wrote:

David Nebenzahl<nobody@but.us.chickens> wrote in
news:4c91a6a6$0$2405$822641b3@news.adtechcomputers.com:

snip

Thanks for the first and only really helpful reply in this
whole damn thread.

You, sir, are a gentleman and a scholar. Sure enough,
removing the nut from the phone jack allowed the whole unit
to slip rather easily out of the case (I used a heavy knife
blade betwixt the case and chassis to start it).

WHAT? You did NOT do that when you removed all the screws? I
have not been reading the thread carefully ever since you
ignored my request for a photograph, but DUUH!

The amp appears to be fine; there's either a problem with
the XLR mike input jack, or with the mike cable we were
using. (Can't test because I have no XLR plugs.)

WHERE are you (as in, forest, garage with NO tools, an audio
shop run by Scientologists who believe the e-meter is the only
piece of electronic test equipment anyone needs) ????????

SIGH.

BTW, I have learned over the last 4 decades that it's ALWAYS the
cable (and if it's not, you **still** test any cables FIRST
before you do ANYTHING, including attempting to open an audio
box [when you should let your friends open your canned food for
you] let alone flooding an NG with clueless posts for a week),
and /had/ you posted like a person with a clue, I would have
told you to try another cable - I know you don't have one, BUY
one!

!!!!!!

In the world of professional audio, it`s hardly ever the cable!