PAT testing damage (UK)

G

Gareth Magennis

Guest
Hi,

I have a Roland drum machine in for repair. The machine powers up and goes
through the Operating System upgrade, up to the point the Flash is written
to, where it fails and the unit will not boot, showing a "damaged memory"
warning. I suspect the Flash chip is faulty.


When I informed the owner of my findings, he then tells me he thinks it was
damaged by a PAT test. It is powered by a Wall Wart, and he thinks it was
plugged into the unit during the test, as it stopped working immediately
afterwards.

An internal inspection shows around 10 caps around the internal power
supplies are bulging and have leaked guff onto the PCB. The 3.3v rail is at
over 4 volts, so presumable the regulator is toast.



So, if you PAT test a Wall Wart plugged into a unit and turned on, what is
likely to happen? What I have just described perhaps?
Or did someone just use the wrong power supply instead and isn't letting on?



Cheers,


Gareth.
 
PAT?

--
Cheers,
WB
..............


"Gareth Magennis" <sound.service@btconnect.com> wrote in message
news:s0YXp.79735$Dk2.59038@newsfe04.ams2...
Hi,

I have a Roland drum machine in for repair. The machine powers up and
goes
through the Operating System upgrade, up to the point the Flash is written
to, where it fails and the unit will not boot, showing a "damaged memory"
warning. I suspect the Flash chip is faulty.


When I informed the owner of my findings, he then tells me he thinks it
was
damaged by a PAT test. It is powered by a Wall Wart, and he thinks it was
plugged into the unit during the test, as it stopped working immediately
afterwards.

An internal inspection shows around 10 caps around the internal power
supplies are bulging and have leaked guff onto the PCB. The 3.3v rail is
at
over 4 volts, so presumable the regulator is toast.



So, if you PAT test a Wall Wart plugged into a unit and turned on, what is
likely to happen? What I have just described perhaps?
Or did someone just use the wrong power supply instead and isn't letting
on?



Cheers,


Gareth.
Click to expand...
 
On Wed, 27 Jul 2011 18:36:27 +0100, "Gareth Magennis"
<sound.service@btconnect.com> wrote:

An internal inspection shows around 10 caps around the internal power
supplies are bulging and have leaked guff onto the PCB. The 3.3v rail is at
over 4 volts, so presumable the regulator is toast.
Click to expand...
Regulator might be toast. Or, you might be measuring a fairly high
ripple current because none of the capacitors are working. Measure it
with an oscilloscope to be sure.


--
Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558
 
On Wed, 27 Jul 2011 14:07:31 -0400, "Wild_Bill"
<wb_wildbill@XSPAMyahoo.com> wrote:

PAT?
Click to expand...
Portable Appliance Test
<http://en.wikipedia.org/wiki/PAT_Testing>

--
Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558
 
"Jeff Liebermann" <jeffl@cruzio.com> wrote in message
news:4ol0379a0u01kimh9u2q2kuh1leiumtffj@4ax.com...
On Wed, 27 Jul 2011 14:07:31 -0400, "Wild_Bill"
wb_wildbill@XSPAMyahoo.com> wrote:

PAT?

Portable Appliance Test
http://en.wikipedia.org/wiki/PAT_Testing
Click to expand...


Should really be PA Test, but nobody would be able to pronounce it.

A bit like PIN number. (IS there a name for these misnamed things?)




Gareth.
 
On Wed, 27 Jul 2011 19:30:20 +0100, "Gareth Magennis"
<sound.service@btconnect.com> wrote:

"Jeff Liebermann" <jeffl@cruzio.com> wrote in message
news:4ol0379a0u01kimh9u2q2kuh1leiumtffj@4ax.com...
On Wed, 27 Jul 2011 14:07:31 -0400, "Wild_Bill"
wb_wildbill@XSPAMyahoo.com> wrote:

PAT?

Portable Appliance Test
http://en.wikipedia.org/wiki/PAT_Testing

Should really be PA Test, but nobody would be able to pronounce it.
A bit like PIN number. (IS there a name for these misnamed things?)
Gareth.
Click to expand...
Yes. See:
<http://en.wikipedia.org/wiki/RAS_syndrome>

Note that we don't have PAT testers in the USA. As part of our
governments War on Industry, we trust the outsourced manufacturures in
China to produce consumer appliances that electrocute only a modest
number of users. We also enjoy the protection of a litigatory
environment, that inspires massive recalls if one defective appliance
is found on the theory that if one is defective, then the entire
production run is also likely to be defective. We also have various
testing and certification labs, that will guarantee that an appliance
design will not kill the user or initiate a fire, even if the
appliance doesn't work. With these protections in place, there's no
need for PAT testing.


--
Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558
 
"Jeff Liebermann" <jeffl@cruzio.com> wrote in message
news:ltm037922tlg0sv176iqem7l6l5s872g3s@4ax.com...
On Wed, 27 Jul 2011 19:30:20 +0100, "Gareth Magennis"
sound.service@btconnect.com> wrote:

"Jeff Liebermann" <jeffl@cruzio.com> wrote in message
news:4ol0379a0u01kimh9u2q2kuh1leiumtffj@4ax.com...
On Wed, 27 Jul 2011 14:07:31 -0400, "Wild_Bill"
wb_wildbill@XSPAMyahoo.com> wrote:

PAT?

Portable Appliance Test
http://en.wikipedia.org/wiki/PAT_Testing

Should really be PA Test, but nobody would be able to pronounce it.
A bit like PIN number. (IS there a name for these misnamed things?)
Gareth.

Yes. See:
http://en.wikipedia.org/wiki/RAS_syndrome

Note that we don't have PAT testers in the USA. As part of our
governments War on Industry, we trust the outsourced manufacturures in
China to produce consumer appliances that electrocute only a modest
number of users. We also enjoy the protection of a litigatory
environment, that inspires massive recalls if one defective appliance
is found on the theory that if one is defective, then the entire
production run is also likely to be defective. We also have various
testing and certification labs, that will guarantee that an appliance
design will not kill the user or initiate a fire, even if the
appliance doesn't work. With these protections in place, there's no
need for PAT testing.
Click to expand...

Well that's just great, Jeff!

In the UK we expect cheap crap to break, and to subsequently kill people.
The fact that it never really has doesn't stop our enthusiasm for Health And
Safety in spades.

Thanks for the RAS syndrome link.
I've always chuckled at the naming of the programming language GNU, the
acronym for "GNU's Not Unix".



Gareth.
 
"Jeff Liebermann is a Clueless Idiot "
Note that we don't have PAT testers in the USA.
Click to expand...
** Shame on you.


As part of our
governments War on Industry, we trust the outsourced manufacturures in
China to produce consumer appliances that electrocute only a modest
number of users. We also enjoy the protection of a litigatory
environment, that inspires massive recalls if one defective appliance
is found on the theory that if one is defective, then the entire
production run is also likely to be defective. We also have various
testing and certification labs, that will guarantee that an appliance
design will not kill the user or initiate a fire, even if the
appliance doesn't work. With these protections in place, there's no
need for PAT testing.
Click to expand...

** Got NOTHING to do with PAT testing !!!

PAT testing is all about the possibility that electrical equipment may
become unsafe after a period of use, due to wear and tear, accidental damage
and water ingress.

It is only *required* to be done were equipment is of a portable kind and
provided for staff and others to use in a work environment.

For example, hire businesses have to regularly PAT test any electrical items
they rent to folk.

It's an idea dreamt up by bureaucrats - and rather pointless since
electrical faults and damage occur at ANY time and PAT testing does nothing
to prevent that.



..... Phil
 
Gareth Magennis <sound.service@btconnect.com> wrote in message
news:s0YXp.79735$Dk2.59038@newsfe04.ams2...
Hi,

I have a Roland drum machine in for repair. The machine powers up and
goes
through the Operating System upgrade, up to the point the Flash is written
to, where it fails and the unit will not boot, showing a "damaged memory"
warning. I suspect the Flash chip is faulty.


When I informed the owner of my findings, he then tells me he thinks it
was
damaged by a PAT test. It is powered by a Wall Wart, and he thinks it was
plugged into the unit during the test, as it stopped working immediately
afterwards.

An internal inspection shows around 10 caps around the internal power
supplies are bulging and have leaked guff onto the PCB. The 3.3v rail is
at
over 4 volts, so presumable the regulator is toast.



So, if you PAT test a Wall Wart plugged into a unit and turned on, what is
likely to happen? What I have just described perhaps?
Or did someone just use the wrong power supply instead and isn't letting
on?



Cheers,


Gareth.
Click to expand...

Now if a numb-skull used the discrete IEC lead tester, flash-tester, instead
of the more down-to-ground ;-) PAT tester then expect such damage
 
"Gareth Magennis" <sound.service@btconnect.com> wrote in message
news:s0YXp.79735$Dk2.59038@newsfe04.ams2...
Hi,

I have a Roland drum machine in for repair. The machine powers up and
goes
through the Operating System upgrade, up to the point the Flash is written
to, where it fails and the unit will not boot, showing a "damaged memory"
warning. I suspect the Flash chip is faulty.


When I informed the owner of my findings, he then tells me he thinks it
was
damaged by a PAT test. It is powered by a Wall Wart, and he thinks it was
plugged into the unit during the test, as it stopped working immediately
afterwards.

An internal inspection shows around 10 caps around the internal power
supplies are bulging and have leaked guff onto the PCB. The 3.3v rail is
at
over 4 volts, so presumable the regulator is toast.



So, if you PAT test a Wall Wart plugged into a unit and turned on, what is
likely to happen? What I have just described perhaps?
Or did someone just use the wrong power supply instead and isn't letting
on?



Cheers,


Gareth.
Click to expand...
Over the years, I've seen a lot of items from schools and commercial
premises that have odd microprocessor-y problems, and a recent PAT sticker
on them, so I'm certain in my own mind, that these have suffered damage as a
result of either inept or inappropriate use of a tester. The items in
question, are often boom boxes that are double insulated, and have a
removable figure 8 power lead, so there is absolutely no point in applying
these tests, anyway. As to wall-wart powered stuff, I can't recall ever
seeing an item that may have been damaged in such a way, but if other items
with a similar small power transformer fixed internally can suffer, I don't
see why it shouldn't also be the case for an externally powered device. I
think, however, with the bulging caps you say you've found, in this case
it's probably either a wrong power supply having been used, or just general
failure, rather than a PAT issue. Is it from a school ? If it is, it's
probably either left on all the time, or subject to dopey kids and teachers
digging it out of a cupboard in the music room, and jamming in the first
power connector that fits, and appears to make it work ...

Arfa
 
"Arfa Daily" <arfa.daily@ntlworld.com> wrote in message
news:FS8Yp.65819$Sr.16865@newsfe12.ams2...
"Gareth Magennis" <sound.service@btconnect.com> wrote in message
news:s0YXp.79735$Dk2.59038@newsfe04.ams2...
Hi,

I have a Roland drum machine in for repair. The machine powers up and
goes
through the Operating System upgrade, up to the point the Flash is
written
to, where it fails and the unit will not boot, showing a "damaged memory"
warning. I suspect the Flash chip is faulty.


When I informed the owner of my findings, he then tells me he thinks it
was
damaged by a PAT test. It is powered by a Wall Wart, and he thinks it
was
plugged into the unit during the test, as it stopped working immediately
afterwards.

An internal inspection shows around 10 caps around the internal power
supplies are bulging and have leaked guff onto the PCB. The 3.3v rail is
at
over 4 volts, so presumable the regulator is toast.



So, if you PAT test a Wall Wart plugged into a unit and turned on, what
is
likely to happen? What I have just described perhaps?
Or did someone just use the wrong power supply instead and isn't letting
on?



Cheers,


Gareth.

Over the years, I've seen a lot of items from schools and commercial
premises that have odd microprocessor-y problems, and a recent PAT sticker
on them, so I'm certain in my own mind, that these have suffered damage as
a result of either inept or inappropriate use of a tester. The items in
question, are often boom boxes that are double insulated, and have a
removable figure 8 power lead, so there is absolutely no point in applying
these tests, anyway. As to wall-wart powered stuff, I can't recall ever
seeing an item that may have been damaged in such a way, but if other
items with a similar small power transformer fixed internally can suffer,
I don't see why it shouldn't also be the case for an externally powered
device. I think, however, with the bulging caps you say you've found, in
this case it's probably either a wrong power supply having been used, or
just general failure, rather than a PAT issue. Is it from a school ? If it
is, it's probably either left on all the time, or subject to dopey kids
and teachers digging it out of a cupboard in the music room, and jamming
in the first power connector that fits, and appears to make it work ...

Arfa
Click to expand...

Thanks Arfa, I was hoping for some real world experience.

This units power supply also has a 2 core mains lead, the 13A plug having a
proper metal pin, so could be mistaken for an earthed unit re: PAT testing.
It is not from a school.

I'm not sure what happens with "inappropriate" PAT testing, hence this post.
I was wondering if a high voltage was able to break through or induced to
the secondary winding to zap the unit in question if it was plugged in and
turned on.

As for the bulging caps, it would surely take some power to do this, which I
guess could not come from a PAT tester, though if they were zapped by one,
subsequent use of the unit with its own power supply may cause further
damage?


As per my post, I suspect, like you, this was a "wrong PSU used numpty
error", though any info on the hazards of PAT testing is welcome.



Cheers,



Gareth.
 
"Arfa Daily is Fucked in the Head "

Over the years, I've seen a lot of items from schools and commercial
premises that have odd microprocessor-y problems, and a recent PAT sticker
on them,
Click to expand...

** They all have recent PAT stickers !!!!!!!!!!!!!

What a blatant red herring.


so I'm certain in my own mind,
Click to expand...

** You are a man of very uncertain mind.


that these have suffered damage as a result of either inept or
inappropriate use of a tester.
Click to expand...

** Absolute bollocks.


The items in question, are often boom boxes that are double insulated, and
have a removable figure 8 power lead, so there is absolutely no point in
applying these tests, anyway.
Click to expand...

** The reverse is true.

Class 2 items are the most important to PAT test - as they RELY, 100%,
on insulation quality to be safe.

So the leakage test is ESSENTIAL !


As to wall-wart powered stuff, I can't recall ever seeing an item that may
have been damaged in such a way, but if other items with a similar small
power transformer fixed internally can suffer,
Click to expand...
** Massive false presumption.

Wot an utter imbecile.


I don't see ....
Click to expand...

** The only correct statement.

AD is an utter IMBECILE.



..... Phil
 
"Gareth Magennis"

As per my post, I suspect, like you, this was a "wrong PSU used numpty
error", though any info on the hazards of PAT testing is welcome.
Click to expand...

**Another, bloody pathetic, WOFT troll.




..... Phil
 
"Phil Allison" <phil_a@tpg.com.au> wrote in message
news:99d03qFm7cU1@mid.individual.net...
"Gareth Magennis"


As per my post, I suspect, like you, this was a "wrong PSU used numpty
error", though any info on the hazards of PAT testing is welcome.



**Another, bloody pathetic, WOFT troll.




.... Phil
Click to expand...


What a charming man.


OK, I have looked a little deeper into this problem now with a schematic,
and it seems that all the electro caps on both sides of the 3 main regulator
circuits are bursting, as are a few smaller ones dotted about the PCB.
Unless a PAT tester can somehow damage all these caps downline of the
regulators, without blowing the regulators, I now suspect this to be a bad
batch of electrolytics.

The 4.1 volts I measured at the 3.3v regulator is, as Jeff suggested, due to
ten tons of ripple and HF hash. Replacing the 3 on the 3.3v regulator
restores it to 3.3v with a bit of ripple, so this reg is probably OK.


The caps are green Jamicon 105degree types. All 220uF 16v ones have blown,
as have a few 100uF 16v of the same type. All the 10uF 16v ones dotted
about look OK.


What fun.


Gareth.
 
On Wed, 27 Jul 2011 18:36:27 +0100, "Gareth Magennis"
<sound.service@btconnect.com> wrote:

Hi,

I have a Roland drum machine in for repair. The machine powers up and goes
through the Operating System upgrade, up to the point the Flash is written
to, where it fails and the unit will not boot, showing a "damaged memory"
warning. I suspect the Flash chip is faulty.


When I informed the owner of my findings, he then tells me he thinks it was
damaged by a PAT test. It is powered by a Wall Wart, and he thinks it was
plugged into the unit during the test, as it stopped working immediately
afterwards.

An internal inspection shows around 10 caps around the internal power
supplies are bulging and have leaked guff onto the PCB. The 3.3v rail is at
over 4 volts, so presumable the regulator is toast.



So, if you PAT test a Wall Wart plugged into a unit and turned on, what is
likely to happen? What I have just described perhaps?
Or did someone just use the wrong power supply instead and isn't letting on?
Click to expand...
Possibly. In general, wall warts are class II items with no earth pin
so visual inspection is all I would do.
In the (unlikely) event that it was a Class I device with earth pin
and exposed metalwork then a voltage test would be made between line
and the metalwork and a resistance check from metal to earth pin.
I would not test a wall wart with equipment (e.g. printer) connected
as the equipment will be working on low voltage and not be subject to
testing.
I doubt that a short pulse of high voltage would cause caps to bulge
anyway.
 
"Phil Allison" <phil_a@tpg.com.au> wrote in message
news:99d00tFli3U1@mid.individual.net...
"Arfa Daily is Fucked in the Head "


Over the years, I've seen a lot of items from schools and commercial
premises that have odd microprocessor-y problems, and a recent PAT
sticker on them,


** They all have recent PAT stickers !!!!!!!!!!!!!

What a blatant red herring.


so I'm certain in my own mind,


** You are a man of very uncertain mind.
Click to expand...


Ha ! And that from a fuckin' madman like you ???!!! At least I don't need a
psychiatrist and powerful drugs to keep me under control ...



that these have suffered damage as a result of either inept or
inappropriate use of a tester.


** Absolute bollocks.


The items in question, are often boom boxes that are double insulated,
and have a removable figure 8 power lead, so there is absolutely no point
in applying these tests, anyway.


** The reverse is true.

Class 2 items are the most important to PAT test - as they RELY, 100%,
on insulation quality to be safe.

So the leakage test is ESSENTIAL !
Click to expand...

Leakage from where to where ?


As to wall-wart powered stuff, I can't recall ever seeing an item that
may have been damaged in such a way, but if other items with a similar
small power transformer fixed internally can suffer,

** Massive false presumption.

Wot an utter imbecile.


I don't see ....


** The only correct statement.

AD is an utter IMBECILE.



.... Phil
Click to expand...
And you, Philip, as I and lots of others have told you many times in the
past, are a fat greasy antipodean twat. So unless you can get your sensible
head that you've had for the last few weeks, back on your shoulders and say
something constructive, fuck off back under your rock. And I'll remember
what an IMBECILE I apparently am, next time you need a Marshall manual and
can't get it ... Arsehole ....

Arfa
 
"Arfa Daily is Fucked in the Head "
The items in question, are often boom boxes that are double insulated,
and have a removable figure 8 power lead, so there is absolutely no
point in applying these tests, anyway.


** The reverse is true.

Class 2 items are the most important to PAT test - as they RELY,
100%, on insulation quality to be safe.

So the leakage test is ESSENTIAL !



Leakage from where to where ?
Click to expand...

** My god - are YOU really a service tech ??


FYI - you asinine pommy fuckwit:

From both the AC supply pins to any exposed metal parts

- including all connectors.
-----------------------------


How can ** ANYONE ** be so fucking dumb to not realise that ??

AD needs a HUGE fucking kick up his fact stinking arse.

An then the fucking cunt needs to retire before he fucking KILLS someone.


WOT A FUCKING ASS !!!!!




..... Phil
 
"Geo"
Possibly. In general, wall warts are class II items with no earth pin
so visual inspection is all I would do.
Click to expand...

** Then YOU also need a fucking good kick up the ARSE as well !!

The MONSTROUS ignorance of BASIC electrical safety is

FUCKING APPALLING here ........





.... Phil
 
On Thu, 28 Jul 2011 09:45:18 +1000, "Phil Allison" <phil_a@tpg.com.au>
wrote:

"Jeff Liebermann is a Clueless Idiot "

Note that we don't have PAT testers in the USA.

** Shame on you.
Click to expand...
It wasn't my decision. We have the best government and regulatory
agencies that money can buy.

As part of our
governments War on Industry, we trust the outsourced manufacturures in
China to produce consumer appliances that electrocute only a modest
number of users. We also enjoy the protection of a litigatory
environment, that inspires massive recalls if one defective appliance
is found on the theory that if one is defective, then the entire
production run is also likely to be defective. We also have various
testing and certification labs, that will guarantee that an appliance
design will not kill the user or initiate a fire, even if the
appliance doesn't work. With these protections in place, there's no
need for PAT testing.

** Got NOTHING to do with PAT testing !!!
Click to expand...
Not even a little bit?

PAT testing is all about the possibility that electrical equipment may
become unsafe after a period of use, due to wear and tear, accidental damage
and water ingress.
Click to expand...
That's not a problem in the USA. We have the worlds best throw away
society. Our tools and electrical equipment are never allowed to get
old enough to become dangerous. No self respecting government
employee would even consider using a used tool or machine. At the
first sign of wear or damage, the device is immediately thrown away,
err... recycled, and replaced with a brand new Chinese replacement.
This may also explain why the USA is nearly bankrupt.

It is only *required* to be done were equipment is of a portable kind and
provided for staff and others to use in a work environment.
Click to expand...
In the USA, workers and staff are largely expendable. In some cases,
the tools and equipment are worth more than the operator. I don't see
much reason for an expensive PAT tester, when simply replacing the
operator will probably be cheaper.

For example, hire businesses have to regularly PAT test any electrical items
they rent to folk.
Click to expand...
Yeah, that makes sense. The tools and equipment that isn't recycled
or stolen, usually ends up at the local rental yards. I recently had
to rent a chain saw with a big 36" bar. While not electrical, it
would not have passed even a cursory safety inspection. Instead of
mandating PAT testing, perhaps it might be better to give the money
back to the businesses so they can afford to buy new equipment?

It's an idea dreamt up by bureaucrats - and rather pointless since
electrical faults and damage occur at ANY time and PAT testing does nothing
to prevent that.
Click to expand...
But, if it saves one life, it must obviously be worth the cost and
effort. That's also the logic here in the USA, particularly in the
drug and product liability industry. If there's only one victim among
millions of perfectly safe users, that's sufficient grounds for
extorting substantial sums from the vendors and enriching the legal
establishment. The search for victims has even extended to TV
advertising by law firms.


--
Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558
 
On Thu, 28 Jul 2011 10:04:30 +0100, "Gareth Magennis"
<sound.service@btconnect.com> wrote:

As for the bulging caps, it would surely take some power to do this, which I
guess could not come from a PAT tester, though if they were zapped by one,
subsequent use of the unit with its own power supply may cause further
damage?
Click to expand...
Just a minor note... It takes some time for bulging caps to develop.
It's unlikely that there's enough energy in a wall wart to destroy the
caps during a PAT test. It's also not over voltage that kills the
caps. It's the ripple current through the cap that causes the
heating. A cap, with a fixed DC voltage applied, will not blow
(unless the dielectric is perforated). More likely, the caps were
defective and blown for many months prior to the PAT test.


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