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Anyone have a Schematic for a Fender Acoustasonic 90?



 
 
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  #21  
Old August 3rd 19, 12:48 AM posted to rec.audio.pro
Phil Allison[_4_]
external usenet poster
 
Posts: 394
Default Anyone have a Schematic for a Fender Acoustasonic 90?

John Williamson wrote:


John Williamson is a Dead **** LIAR wrote:


> Phil Allison the ONLY serious poster here wrote:



** This stinking **** posted nothing but malicious lies and wild bull****.

And he just posted some more.

I have no idea exactly what the hell is wrong with the demented old fool but he sure is one KING SIZE ****ing asshole.

Sad that folk his age deteriorate into complete ****wits before they die.

Be far better if they died first.



..... Phil,

very ****ed off by the lunatic scum that post here, unfortunately I already very well know that the world of pro audio is FULL of them.



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  #22  
Old August 3rd 19, 01:46 AM posted to rec.audio.pro
Scott Dorsey
external usenet poster
 
Posts: 16,602
Default Anyone have a Schematic for a Fender Acoustasonic 90?

John Williamson > wrote:
>
>Please check Phil Allison's previous posting record. He has a habit of
>accusing others of suffering from his own shortcomings. While he has a
>reasonable knowledge of certain aspects of the audio business, he shows,
>when posting, personality problems which vary in seriousness for no
>apparent reason. He is banned from many usenet and other social media
>groups for this reason.


This is true.

Now, he does have a good point that the original poster likely doesn't
have the right equipment or skills to diagnose the problem. But....
everybody has to start somewhere and if you don't try you'll never learn.

>He is also resident in the kill files of many posters here, and posters
>responding to him as you have also end up in the kill files, so do not
>get the hep they would like.


He posts interesting and accurate stuff often enough that I am reluctant to
killfile him, although he will go on these weird rants occasionally.

>With proper precautions, working on SMPS units is perfectly safe. I hate
>doing it, because I dislike working on SMDs as my eyesight is not what
>is used to be.


Two things changed my mind about this: the Optivisor magnifier (accept no
cheap Asian substitutes!) and the hot tweezers. The tweezers allow you to
pick up an smt resistor, put it aside, then put it back as needed. It makes
working on smt discretes much much easier. I had no idea how wonderful
either one of these things was until I tried them.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."
  #23  
Old August 3rd 19, 02:39 AM posted to rec.audio.pro
Phil Allison[_4_]
external usenet poster
 
Posts: 394
Default Anyone have a Schematic for a Fender Acoustasonic 90?

Scott Dorsey wrote:
>
> He is banned from many usenet and other social media
> >groups for this reason.

>
> This is true.
>


** I challenge you to say which forums you think they are.

Cos I know I have never been excluded from any internet forum.

However, I am responsible for the demise of AAPLS, a intolerable nest of crooks & vipers so I am justly proud of doing that.


...... Phil
  #24  
Old August 3rd 19, 10:52 AM posted to rec.audio.pro
Paul[_13_]
external usenet poster
 
Posts: 869
Default Anyone have a Schematic for a Fender Acoustasonic 90?

On 8/2/2019 5:46 PM, Scott Dorsey wrote:
> John Williamson > wrote:
>>
>> Please check Phil Allison's previous posting record. He has a habit of
>> accusing others of suffering from his own shortcomings. While he has a
>> reasonable knowledge of certain aspects of the audio business, he shows,
>> when posting, personality problems which vary in seriousness for no
>> apparent reason. He is banned from many usenet and other social media
>> groups for this reason.

>
> This is true.
>
> Now, he does have a good point that the original poster likely doesn't
> have the right equipment or skills to diagnose the problem. But....
> everybody has to start somewhere and if you don't try you'll never learn.



I've got a Tektronix 465M o'scope, a digital multimeter, and an ESR
meter.

What more do you need?

And having been a microwave/Radio frequency engineer for nearly 3
decades, I'm not likely to electrocute myself on the bench!

But I'll admit I don't trouble-shoot modern switching power supplies
very often. But it can't be denied that these are NOT trivial circuits
to diagnose, especially WITHOUT a proper schematic!

And even your article mentions the when-in-doubt-replace-it, brute
force approach to repairing these tough-dog problems. I've certainly
successfully done this in the past, but I'm not sure I wanna do that
on this unit, because my stock of spare parts is not what it used to
be.

:/

This unit might end up on Ebay.....

Haha!


>
>> He is also resident in the kill files of many posters here, and posters
>> responding to him as you have also end up in the kill files, so do not
>> get the hep they would like.

>
> He posts interesting and accurate stuff often enough that I am reluctant to
> killfile him, although he will go on these weird rants occasionally.
>
>> With proper precautions, working on SMPS units is perfectly safe. I hate
>> doing it, because I dislike working on SMDs as my eyesight is not what
>> is used to be.

>
> Two things changed my mind about this: the Optivisor magnifier (accept no
> cheap Asian substitutes!) and the hot tweezers. The tweezers allow you to
> pick up an smt resistor, put it aside, then put it back as needed. It makes
> working on smt discretes much much easier. I had no idea how wonderful
> either one of these things was until I tried them.
> --scott
>


  #25  
Old August 3rd 19, 04:46 PM posted to rec.audio.pro
Scott Dorsey
external usenet poster
 
Posts: 16,602
Default Anyone have a Schematic for a Fender Acoustasonic 90?

In article >, Paul > wrote:
>On 8/2/2019 5:46 PM, Scott Dorsey wrote:
>>
>> Now, he does have a good point that the original poster likely doesn't
>> have the right equipment or skills to diagnose the problem. But....
>> everybody has to start somewhere and if you don't try you'll never learn.

>
> I've got a Tektronix 465M o'scope, a digital multimeter, and an ESR
>meter.


Get a load bank and a storage scope and you'll probably be set. The storage
scope is REALLY handy to look at the startup of the pwm ic because it's only
a few milliseconds long. If it's not repeatedly shutting down, it can be
sometimes shutting down on the first try, and then the storage tube tells you
what is going on. BUT... the good news is that with these all-in-one PWM ICs,
there are only a few static voltages that can cause it to turn on or off, so
usually by looking at static voltages you can see what is going on. With
discrete transistor PWM circuits you need the storage tube.

If you haven't used the ESR meter on every electrolytic, now is the time.
Even if they aren't related to the problem, you may pre-empt future failures.

> And having been a microwave/Radio frequency engineer for nearly 3
>decades, I'm not likely to electrocute myself on the bench!


This puts you in the category of the "goddamn white hat engineers" and makes
it that much less likely that you should touch a soldering iron. I'm in
that category myself, but at least I don't have a PhD so I am reasonably safe.

> But I'll admit I don't trouble-shoot modern switching power supplies
>very often. But it can't be denied that these are NOT trivial circuits
>to diagnose, especially WITHOUT a proper schematic!


I apprenticed at a TV repair shop in the days of sweep tubes locked up in
high voltage cages and all the set voltages being derived from the flyback,
and it was amazing seeing some of the tricks. Guys used to run a TV set in
series with a 500W light bulb as a current limiter so they could keep them
going long enough to diagnose oscillation issues. Sometimes with schematics,
but mostly without.

> And even your article mentions the when-in-doubt-replace-it, brute
>force approach to repairing these tough-dog problems. I've certainly
>successfully done this in the past, but I'm not sure I wanna do that
>on this unit, because my stock of spare parts is not what it used to
>be.


That's easy to fix with a digikey order. Pick up ten of every common PWM
chip too, because sooner or later you'll need them.

> This unit might end up on Ebay.....
>
> Haha!


See, that is giving up. That is not right.
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."
  #26  
Old August 3rd 19, 05:24 PM posted to rec.audio.pro
david gourley[_4_]
external usenet poster
 
Posts: 8
Default Anyone have a Schematic for a Fender Acoustasonic 90?

Paul > :

> On 8/2/2019 5:46 PM, Scott Dorsey wrote:
>> John Williamson > wrote:
>>>
>>> Please check Phil Allison's previous posting record. He has a habit of
>>> accusing others of suffering from his own shortcomings. While he has a
>>> reasonable knowledge of certain aspects of the audio business, he

shows,
>>> when posting, personality problems which vary in seriousness for no
>>> apparent reason. He is banned from many usenet and other social media
>>> groups for this reason.

>>
>> This is true.
>>
>> Now, he does have a good point that the original poster likely doesn't
>> have the right equipment or skills to diagnose the problem. But....
>> everybody has to start somewhere and if you don't try you'll never

learn.
>
>
> I've got a Tektronix 465M o'scope, a digital multimeter, and an ESR
> meter.
>
> What more do you need?
>


Other than what Scott suggested, an isolation transformer would be a good
safety measure. The input circuit typically carries all of the (hazardous)
potential of the wall socket. Phil also said this but the screed had
begun.


-snip remaining-


david

---
This email has been checked for viruses by Avast antivirus software.
https://www.avast.com/antivirus

  #27  
Old August 3rd 19, 06:45 PM posted to rec.audio.pro
Paul[_13_]
external usenet poster
 
Posts: 869
Default Anyone have a Schematic for a Fender Acoustasonic 90?

On 8/3/2019 8:46 AM, Scott Dorsey wrote:
> In article >, Paul > wrote:
>> On 8/2/2019 5:46 PM, Scott Dorsey wrote:
>>>
>>> Now, he does have a good point that the original poster likely doesn't
>>> have the right equipment or skills to diagnose the problem. But....
>>> everybody has to start somewhere and if you don't try you'll never learn.

>>
>> I've got a Tektronix 465M o'scope, a digital multimeter, and an ESR
>> meter.

>
> Get a load bank and a storage scope and you'll probably be set. The storage
> scope is REALLY handy to look at the startup of the pwm ic because it's only
> a few milliseconds long. If it's not repeatedly shutting down, it can be
> sometimes shutting down on the first try, and then the storage tube tells you
> what is going on. BUT... the good news is that with these all-in-one PWM ICs,
> there are only a few static voltages that can cause it to turn on or off, so
> usually by looking at static voltages you can see what is going on. With
> discrete transistor PWM circuits you need the storage tube.


Good point. A storage scope would be a nice addition.

>
> If you haven't used the ESR meter on every electrolytic, now is the time.
> Even if they aren't related to the problem, you may pre-empt future failures.
>
>> And having been a microwave/Radio frequency engineer for nearly 3
>> decades, I'm not likely to electrocute myself on the bench!

>
> This puts you in the category of the "goddamn white hat engineers" and makes
> it that much less likely that you should touch a soldering iron. I'm in
> that category myself, but at least I don't have a PhD so I am reasonably safe.


I've done plenty of bench engineering, and REAL engineers do
at least SOME of their own soldering!



>
>> But I'll admit I don't trouble-shoot modern switching power supplies
>> very often. But it can't be denied that these are NOT trivial circuits
>> to diagnose, especially WITHOUT a proper schematic!

>
> I apprenticed at a TV repair shop in the days of sweep tubes locked up in
> high voltage cages and all the set voltages being derived from the flyback,
> and it was amazing seeing some of the tricks. Guys used to run a TV set in
> series with a 500W light bulb as a current limiter so they could keep them
> going long enough to diagnose oscillation issues. Sometimes with schematics,
> but mostly without.
>
>> And even your article mentions the when-in-doubt-replace-it, brute
>> force approach to repairing these tough-dog problems. I've certainly
>> successfully done this in the past, but I'm not sure I wanna do that
>> on this unit, because my stock of spare parts is not what it used to
>> be.

>
> That's easy to fix with a digikey order. Pick up ten of every common PWM
> chip too, because sooner or later you'll need them.
>
>> This unit might end up on Ebay.....
>>
>> Haha!

>
> See, that is giving up. That is not right.


The "shotgun" approach of replacing components,
until the unit works, often does work, but I have to balance
the cost of the parts, and what I want to spend my time doing,
versus what I expect to gain at the end.

But you are right: I'm kinda lazy, and I'm more into the
money, than the knowledge, to be honest, especially at my middle age.

I prefer to call it: Selective Cut and Run!



I mean, sometimes you can make more money, and save
yourself some aggravation, by selling the parts of a unit,
instead of repairing it yourself.



> --scott
>


  #28  
Old August 3rd 19, 10:43 PM posted to rec.audio.pro
Phil Allison[_4_]
external usenet poster
 
Posts: 394
Default Anyone have a Schematic for a Fender Acoustasonic 90?

Paul the Raving Lunatic and Psychopath wrote:
--------------------------------------------
>
>
> I've got a Tektronix 465M o'scope, a digital multimeter, and an ESR
> meter.
>
> What more do you need?
>


** A functioning brain and is also needed.

And an earth leakage circuit breaker.



> And having been a microwave/Radio frequency engineer for nearly 3
> decades, I'm not likely to electrocute myself on the bench!
>


** What an absurd non-sequitur.

Paul has been a schizophrenic most his life too.


> But I'll admit I don't trouble-shoot modern switching power supplies
> very often. But it can't be denied that these are NOT trivial circuits
> to diagnose, especially WITHOUT a proper schematic!
>


** Paul simply has no ****ing idea why he is being criticized by me or anyone else.

Like I posted already, no-one will miss him when he dies.



..... Phil
  #29  
Old August 4th 19, 01:50 AM posted to rec.audio.pro
geoff
external usenet poster
 
Posts: 1,508
Default Anyone have a Schematic for a Fender Acoustasonic 90?

On 3/08/2019 9:52 PM, Paul wrote:
> On 8/2/2019 5:46 PM, Scott Dorsey wrote:
>> John Williamson¬* > wrote:
>>>
>>> Please check Phil Allison's previous posting record. He has a habit of
>>> accusing others of suffering from his own shortcomings. While he has a
>>> reasonable knowledge of certain aspects of the audio business, he shows,
>>> when posting, personality problems which vary in seriousness for no
>>> apparent reason. He is banned from many usenet and other social media
>>> groups for this reason.

>>
>> This is true.
>>
>> Now, he does have a good point that the original poster likely doesn't
>> have the right equipment or skills to diagnose the problem.¬* But....
>> everybody has to start somewhere and if you don't try you'll never learn.

>
>
> ¬*¬*¬* I've got a Tektronix 465M o'scope, a digital multimeter, and an ESR
> meter.
>
> ¬*¬*¬* What more do you need?


Maggy-lamp for a quick check on things before diving in. Check
switching transistors and PWM controller chip for cracks in casing. Also
some have a opto-isolator than can blows up.

geoff
 




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