sci.electronics.repair - 19 new messages in 8 topics - digest

sci.electronics.repair
http://groups.google.com/group/sci.electronics.repair?hl=en

sci.electronics.repair@googlegroups.com

Today's topics:

==============================================================================
TOPIC: Fire ants - computer bugs
http://groups.google.com/group/sci.electronics.repair/t/7eecdfe1b1971fbf?hl=en
==============================================================================

== 1 of 1 ==
Date: Mon, Jun 28 2010 10:22 am
From: Phil Hobbs

On 6/27/2010 11:45 AM, Ron wrote:
> On 27/06/2010 16:36, Meat Plow wrote:
>> On Sun, 27 Jun 2010 07:59:49 +0100, N_Cook ǝʇoɹʍ:
>>
>>> Watched a nature TV prog on swarming behavior. Apparently these ants
>>> have stowed away on planes and taken up residence in airports in S USA
>>> states , infesting computers in air traffic systems etc. No mention in
>>> the program why jungle creatures have electric charge sensors in their
>>> antenna (stated in the narration) but they naturally home in on live
>>> circuit boards apparently and then swarm all over, causing mayhem.
>>> Anyone have any operational experience of pc failure due to swarms of
>>> fire ants ?
>>
>> I purchased an Anteater for insurance against a fire ant attack on my
>> electronics.
> you know what they say, aardvark never killed anybody

;)

Cheers

Phil Hobbs

(And it's illegal in some places: http://www.despair.com/effort.html )

--
Dr Philip C D Hobbs
Principal
ElectroOptical Innovations
55 Orchard Rd
Briarcliff Manor NY 10510
845-480-2058

email: hobbs at electrooptical dot net
http://electrooptical.net

==============================================================================
TOPIC: What on earth is a "Class 1 LED Product" ??
http://groups.google.com/group/sci.electronics.repair/t/c114dd1feeb17e72?hl=en
==============================================================================

== 1 of 8 ==
Date: Mon, Jun 28 2010 11:58 am
From: "Anon"

"Arfa Daily" <arfa.daily@ntlworld.com> wrote in message
news:GxZVn.97783$k15.95689@hurricane...
> Today, I had occasion to look at a set top box for cable TV service. It's
> a HDD recorder as well, employing what seems to be a standard computer
> disc drive. When I came to screw the lid back on, I noticed on the back
> panel, the words "Class 1 LED Product". What on earth do they mean by that
> ? I've seen similar statements for laser-based products such as CD players
> or DVD players / recorders, but in those cases, it is a warning. I'm not
> even sure that this unit has any LEDs in it, so in this case, does the
> word "LED" refer to something else ? What are Samsung (the makers of this
> box) trying to tell (warn??) us of here ... ?
>
> Arfa

The Classes assigned to laser products for eye safety are now being applied
to LEDs. I got a replacement 12V Outdoor Lighting Transformer that stated
it can not be used on Class II LED Products. That prompted me to look into
this issue recently. :)

Scott in Dunedin FL

== 2 of 8 ==
Date: Mon, Jun 28 2010 11:12 am
From: Meat Plow

On Mon, 28 Jun 2010 13:58:39 -0500, Anon ǝʇoɹʍ:

> "Arfa Daily" <arfa.daily@ntlworld.com> wrote in message
> news:GxZVn.97783$k15.95689@hurricane...
>> Today, I had occasion to look at a set top box for cable TV service.
>> It's a HDD recorder as well, employing what seems to be a standard
>> computer disc drive. When I came to screw the lid back on, I noticed on
>> the back panel, the words "Class 1 LED Product". What on earth do they
>> mean by that ? I've seen similar statements for laser-based products
>> such as CD players or DVD players / recorders, but in those cases, it
>> is a warning. I'm not even sure that this unit has any LEDs in it, so
>> in this case, does the word "LED" refer to something else ? What are
>> Samsung (the makers of this box) trying to tell (warn??) us of here ...
>> ?
>>
>> Arfa
>
> The Classes assigned to laser products for eye safety are now being
> applied to LEDs. I got a replacement 12V Outdoor Lighting Transformer
> that stated it can not be used on Class II LED Products. That prompted
> me to look into this issue recently. :)

That's pure madness!

== 3 of 8 ==
Date: Mon, Jun 28 2010 11:28 am
From: dplatt@radagast.org (Dave Platt)

In article <kO0Wn.56450$EK1.15950@newsfe15.ams2>,
Arfa Daily <arfa.daily@ntlworld.com> wrote:

>Well, yes, I suppose there is an *indicator* LED, but just the one, and it's
>hidden behind a coloured insert in the front panel, that surrounds a button
>assembly. I suppose if you are being really precise, there is a LED in the
>Toslink socket on the back as well, but then just about every piece of
>consumer electronics in existence now, has an indicator LED, and a Toslink
>socket or two on the back, and I've never seen any other item carry a
>similar statement about LEDs and classes. And to Mark, it's not a more
>accurate statement regarding a semiconductor laser in this case, because
>there's not one in it. No optical drive of any description. It's just a
>cable set top box with an HDD in it for recording.

Does it by any chance have a TOSLINK output, for providing digital-audio
signals to an A/V receiver/amplifier? A lot of STBs do, these days,
and this might require the Class 1 label.

--
Dave Platt <dplatt@radagast.org> AE6EO
Friends of Jade Warrior home page: http://www.radagast.org/jade-warrior
I do _not_ wish to receive unsolicited commercial email, and I will
boycott any company which has the gall to send me such ads!

== 4 of 8 ==
Date: Mon, Jun 28 2010 12:45 pm
From: AZ Nomad

On Mon, 28 Jun 2010 10:01:26 +0100, Arfa Daily <arfa.daily@ntlworld.com> wrote:
>Today, I had occasion to look at a set top box for cable TV service. It's a
>HDD recorder as well, employing what seems to be a standard computer disc
>drive. When I came to screw the lid back on, I noticed on the back panel,
>the words "Class 1 LED Product". What on earth do they mean by that ? I've
>seen similar statements for laser-based products such as CD players or DVD
>players / recorders, but in those cases, it is a warning. I'm not even sure
>that this unit has any LEDs in it, so in this case, does the word "LED"
>refer to something else ? What are Samsung (the makers of this box) trying
>to tell (warn??) us of here ... ?

Anybody know how to locate and power up a computer, open a web browser,
get to google.com and arrive at a clever search string like "Class 1 LED
Product"?

== 5 of 8 ==
Date: Mon, Jun 28 2010 1:48 pm
From: Adrian C

On 28/06/2010 20:45, AZ Nomad wrote:

> Anybody know how to locate and power up a computer, open a web browser,
> get to google.com and arrive at a clever search string like "Class 1 LED
> Product"?

No. Is that possible?

Do I need to wear any special protection while doing that?

--
Adrian C

== 6 of 8 ==
Date: Mon, Jun 28 2010 1:56 pm
From: AZ Nomad

On Mon, 28 Jun 2010 21:48:35 +0100, Adrian C <email@here.invalid> wrote:
>On 28/06/2010 20:45, AZ Nomad wrote:

>> Anybody know how to locate and power up a computer, open a web browser,
>> get to google.com and arrive at a clever search string like "Class 1 LED
>> Product"?

>No. Is that possible?

>Do I need to wear any special protection while doing that?

Doesn't microsoft have a warning "this browser is shit, using it may
destroy your computer and all the data that you hold dear, continue?"

== 7 of 8 ==
Date: Mon, Jun 28 2010 2:33 pm
From: Adrian C

On 28/06/2010 21:56, AZ Nomad wrote:
> On Mon, 28 Jun 2010 21:48:35 +0100, Adrian C<email@here.invalid> wrote:
>> On 28/06/2010 20:45, AZ Nomad wrote:
>
>>> Anybody know how to locate and power up a computer, open a web browser,
>>> get to google.com and arrive at a clever search string like "Class 1 LED
>>> Product"?
>
>> No. Is that possible?
>
>> Do I need to wear any special protection while doing that?
>
> Doesn't microsoft have a warning "this browser is shit, using it may
> destroy your computer and all the data that you hold dear, continue?"

'Yeah, but I find pressing the escape key cancels boring things that
might be confusing to me to read and it doesn't seem to do any harm ....'

(one of my users in care...)

--
Adrian C

== 8 of 8 ==
Date: Mon, Jun 28 2010 5:50 pm
From: David Nebenzahl

On 6/28/2010 2:33 PM Adrian C spake thus:

> On 28/06/2010 21:56, AZ Nomad wrote:
>
>> On Mon, 28 Jun 2010 21:48:35 +0100, Adrian C<email@here.invalid> wrote:
>>
>>> On 28/06/2010 20:45, AZ Nomad wrote:
>>>
>>>> Anybody know how to locate and power up a computer, open a web browser,
>>>> get to google.com and arrive at a clever search string like "Class 1 LED
>>>> Product"?
>>>
>>> No. Is that possible?
>>>
>>> Do I need to wear any special protection while doing that?
>>
>> Doesn't microsoft have a warning "this browser is shit, using it may
>> destroy your computer and all the data that you hold dear, continue?"
>
> 'Yeah, but I find pressing the escape key cancels boring things that
> might be confusing to me to read and it doesn't seem to do any harm ....'

Well, that's kinda true: pressing <ESC> at any prompt is kinda like
voting "no" on all ballot propositions (we get a lot of 'em here in
Kal-ee-fonia).

--
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)

==============================================================================
TOPIC: DATAMAN s4 eprom programmer , looking for GAL adaptor...
http://groups.google.com/group/sci.electronics.repair/t/2b308026e5f71b8d?hl=en
==============================================================================

== 1 of 1 ==
Date: Mon, Jun 28 2010 11:22 am
From: Scheini Karl

On 28 Jun., 14:40, "Jps" <formula1vhsNOS...@hotmail.com> wrote:

> i think i will cannot program any PAL / GAL chip...any idea?

How about GALBLAST?

See: http://www.armory.com/~rstevew/Public/Pgmrs/GAL/_ClikMe1st.htm

regards

Karl

==============================================================================
TOPIC: Teac AG-790 has me stumped...
http://groups.google.com/group/sci.electronics.repair/t/19f1f1c9d95691fb?hl=en
==============================================================================

== 1 of 2 ==
Date: Mon, Jun 28 2010 11:32 am
From: Geo

On Sat, 26 Jun 2010 19:57:31 -0500, "William R. Walsh"
<newsgroups1@idontwantjunqueemail.walshcomptech.com> wrote:

>I kept on looking and found a capacitor at location 7C27 (220uF, 16V) that
>had blown out the rubber plug at the bottom. So I replaced that. Now nothing
>works. I know the new cap to be good.

Is it a double-sided (or worse - multilayer) pcb?
If the pcb designer used one or both of the capacitor pins as vias then you
could possibly have removed sufficient of the hole plating to lose e.g a power
or ground through connection.

--
Geo

== 2 of 2 ==
Date: Mon, Jun 28 2010 5:12 pm
From: "Arfa Daily"

"William R. Walsh" <wm_walsh@hotmail.com> wrote in message
news:016c0e5e-f07c-4ecb-81be-4af0611b1632@r27g2000yqb.googlegroups.com...
> Hello all...
>
> Thanks to everyone for the replies...
>
> The new cap is installed properly. I made careful notes of how the old
> one had been installed and the schematic is in agreement with my
> notes.
>
> I do believe the "E0" indication is some kind of error. But what it
> means is a mystery, and the service manual does not help. I'm going to
> ask TEAC, although so far they have not been helpful at all. The
> output of the amplifier does not appear to be blocked--it is
> amplifying this humming sound. It's not outputting DC to the speaker
> connections.
>
> Outside of the burned area, no traces on the board were ruined.
>
> If I knew what E0 meant, I suppose it might be very helpful.
>
> I may try pulling the cap (since the original was completely open
> circuit, I doubt it can hurt) and seeing how the behavior changes.
>
> William

So what does the cap do in the circuit ? Is it a big secret, or something ?

Arfa

==============================================================================
TOPIC: Slightly OT - Apple OS4 on 2G Touch ...
http://groups.google.com/group/sci.electronics.repair/t/7e38c57ec16b1c11?hl=en
==============================================================================

== 1 of 2 ==
Date: Mon, Jun 28 2010 5:23 pm
From: "Arfa Daily"

"Jeff Liebermann" <jeffl@cruzio.com> wrote in message
news:j7ih26deuf9d1nup0lm7rq2s2ffc2smc5k@4ax.com...
> On Sun, 27 Jun 2010 09:36:01 -0700, Jeff Liebermann <jeffl@cruzio.com>
> wrote:
>
>>I ran a crude test last night. At midnight, my iPod Touch 2G showed
>>97% battery charge (using iSystemPro). 9 hrs later, it's at 89%.
>>Notification is set to check my stocks and eBay items every 15 minutes
>>via Wi-Fi.
>>
>>Here's another app to help run the battery down:
>><https://www.ihoundsoftware.com/ihound/template/iPhone.vm>
>>Much like LoJack for iPod Touch, iPad, etc. I just installed it.
>
> Argh. I installed iHound to send their server my location every 10
> minutes. The default was 3 minutes. I left iHound running overnight.
> The battery went from 97% to 32%. Ouch.
>
> I don't think it's Notifications that are sucking the battery power.
> Methinks the problem is leaving an application running that uses
> notifications or just CPU cycles when the iPod Touch is in standby. I
> usually display the desktop before turning off (actually standby)
> mine, so I haven't had much experience with what an application can do
> to the battery level if left running.
>
> --
> Jeff Liebermann jeffl@cruzio.com

No apps were running to the best of my knowledge, when the problem was
occurring. I installed an app that monitors the system processes, as well as
a lot of other things like the battery, and checked what the state of play
was before putting it to sleep. It showed the processor as being (typically)
96 - 97% idle. There was one app that *wanted* notifications access, but the
app was not running - or at least it wasn't running in the foreground.
Nothing had changed with this app or the way it was loaded, and it had not
caused a problem before. Maybe iOS 4 gives it what it wants in the
background. I guess this may be a bug, and because of that keeps the wifi
running pretty much continuously. I don't know where in the unit the wifi
module is located, but certainly, the back of the case was warm enough to
just about feel, up near the top. It never had been before, and isn't again
now.

I have actually deleted the app that wanted notifications access now, so it
might be an interesting experiment to turn notifications back on. I guess I
could also wave the unit at my spec anny, and see if there is any obvious
wifi activity from it, when it's asleep.

Arfa

== 2 of 2 ==
Date: Mon, Jun 28 2010 6:06 pm
From: Jeff Liebermann

On Tue, 29 Jun 2010 01:23:13 +0100, "Arfa Daily"
<arfa.daily@ntlworld.com> wrote:

>No apps were running to the best of my knowledge, when the problem was
>occurring.

So much for that theory.

>I installed an app that monitors the system processes, as well as
>a lot of other things like the battery, and checked what the state of play
>was before putting it to sleep. It showed the processor as being (typically)
>96 - 97% idle.

That's what you'll usually see. The iPod Touch does not support
(much) multitasking (thank you Apple) so the only application that's
really able to run has to be in the forground and running. An
application can be installed, but unless it has Steve Jobs personal
permission to run in the background, it's not going to burn any CPU
cycles.

>I don't know where in the unit the wifi
>module is located, but certainly, the back of the case was warm enough to
>just about feel, up near the top. It never had been before, and isn't again
>now.

Looking inside:
<http://www.ifixit.com/Teardown/iPod-Touch-2nd-Generation/586/1>
the wi-fi chip is near the top, next to the antenna:
<http://s1.guide-images.ifixit.net/igi/a11UeKjfQfuIIrHD.huge>
next to the gold test coax connector. Mouse over the Broadcom chip in
the right hand photo above the "Step 10" label.

>I have actually deleted the app that wanted notifications access now, so it
>might be an interesting experiment to turn notifications back on. I guess I
>could also wave the unit at my spec anny, and see if there is any obvious
>wifi activity from it, when it's asleep.

A passive Wi-Fi sniffer (Kismet) might show more. Spread Spectrum is
difficult to see on an SA. If Notification is on, you should see some
traffic when it wakes up. However, if you REALLY want to run the
battery down, turn off you wireless router at night. The iPod Touch
will try to find something with which to connect. Not finding any
open access points, it will go through the list of SSID's heard, thus
taking more time, and much more battery power.

--
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

==============================================================================
TOPIC: Orange Rocker 30, combo, 2006
http://groups.google.com/group/sci.electronics.repair/t/fdf96ce609e107d9?hl=en
==============================================================================

== 1 of 3 ==
Date: Mon, Jun 28 2010 5:28 pm
From: "Arfa Daily"

"N_Cook" <diverse@tcp.co.uk> wrote in message
news:i0abre$2i3$1@news.eternal-september.org...
> Definitely PbF, resoldering the usual suspect points.
> I realised I was using the wrong gauge of cut down sewing needle and 2 of
> the preamp valve socket pins are highly suspect. Those glossy white
> ceramic
> mounts with holes just bigger than the valve pins.
>
>
If it continues to cut out, a generator, a 'scope and a meter should tell
all. Valve circuits are very simple and very straightforward to trace
signals in, and troubleshoot. Even if it is a bad PbF joint, it should be
easy enough to pin it down to at least a stage, and possibly to a specific
component, based on valve voltages.

Arfa

== 2 of 3 ==
Date: Mon, Jun 28 2010 6:03 pm
From: "Phil Allison"

"Arfa Daily"
>
> If it continues to cut out, a generator, a 'scope and a meter should tell
> all. Valve circuits are very simple and very straightforward to trace
> signals in, and troubleshoot.

** You don't service that many valve guitar amps - do you ??

The ones that were originally well made are now so old they have strange
faults most techs have never seen before - while the ones made more
recently have designed in faults never seen before by anyone.

A few examples.

1. Recent Marshall combo amps with fibreglass PCBs that become LEAKY when
hot - output valve bias goes crazy and even the phase splitter stage goes
way out of DC balance in normal operation because of leakage from anode
tracks to grid tracks. There is simply no fix for this problem.

2. Recent Gibson /Trace Elliot amps that develop mysterious crackling
noises all over the circuit due to the use of water soluble flux that was
never properly washed of the PCB. Removing the main PCB entirely and
washing it thoroughly in solvent is the only fix.

3. Same amps as above use 9 pin PCB mount sockets that SHRINK - yep,
the plastic material used to make the socket shrinks under the heat from
EL84s, reducing the pitch circle diameter so much it is impossible to fit a
new tube in the socket. Replacing all the output valve sockets is the only
fix.

Then there are all the issues with the valves themselves - all new
production now comes from China or the former USSR and most of the valves
have designed in faults of kinds that were never seen previously. Eg.
nearly all 12AX7s now crackle and pop if tapped with the back of a
screwdriver and/or have bad heater cathode hum or are very microphonic -
while octal power types often suffer from bad soldering (PbF ?) on the pins
causing all manner of weird intermittents when the solder joint lets go.

Yep - fixing valve amps is pure joy.

.... Phil

== 3 of 3 ==
Date: Tues, Jun 29 2010 12:17 am
From: "N_Cook"

Arfa Daily <arfa.daily@ntlworld.com> wrote in message
news:47bWn.34349$9c1.22170@hurricane...
>
>
> "N_Cook" <diverse@tcp.co.uk> wrote in message
> news:i0abre$2i3$1@news.eternal-september.org...
> > Definitely PbF, resoldering the usual suspect points.
> > I realised I was using the wrong gauge of cut down sewing needle and 2
of
> > the preamp valve socket pins are highly suspect. Those glossy white
> > ceramic
> > mounts with holes just bigger than the valve pins.
> >
> >
> If it continues to cut out, a generator, a 'scope and a meter should tell
> all. Valve circuits are very simple and very straightforward to trace
> signals in, and troubleshoot. Even if it is a bad PbF joint, it should be
> easy enough to pin it down to at least a stage, and possibly to a specific
> component, based on valve voltages.
>
> Arfa
>

Coincidence or action of high V on springiness of the socket metal?
One valve base, pin 1 , the other pin 6 , both anodes so killing throughput
if connection fails.

While on valve stuff , has anyone come across any output transformer or
mains transformer ,for that matter, in any equipment , where there is
failure of PbF joint inside the transformer where tail meets magnet wire?

==============================================================================
TOPIC: CLICK AND GET $1000 TO YOUR HOME.
http://groups.google.com/group/sci.electronics.repair/t/2033a5d56897d930?hl=en
==============================================================================

== 1 of 1 ==
Date: Mon, Jun 28 2010 9:55 pm
From: easy money

VISIT SITE http://ukcitygirls.co.cc AND

CLICK SEARCH BOX ABOVE BANNER

AFTER FILL YOUR NAME AND ADDRESS.

YOU CAN GET INSTANT $1000 TO YOUR HOME.

==============================================================================
TOPIC: electric fence , force field B20, 2007
http://groups.google.com/group/sci.electronics.repair/t/9573289f9ec521ea?hl=en
==============================================================================

== 1 of 1 ==
Date: Tues, Jun 29 2010 12:40 am
From: "N_Cook"

8 pin SMD with blown hole in the casing. Top mark , very indistinct maybe 2
lines
0h963
0h37

maybe very stylised 4 instead of h, logo very indistinct. My first guess is
a 555 but pinning not standard
p3 ground, p8 +12V, pin 1 to a 10uF cap , other end to 0V, p5 tied to p6
goes to speed change pot with also a line from the pot to p1. No obvious
output trace.
Removed the device and internal connections between p2 and 3 presumably
fried , and also p6 and 7
Other device is a 16 pin with ident scraped off or the conformal coating
dissolved off.

In passing , a 8x5x3 mm fuse with bo encapsulation , mainly 2 bare Al plates
with something between. Working order measures 0.18R +/-.01R, marked/punched
in the Al
100
B7L
never seen anything like it before
make/series/value?

==============================================================================

You received this message because you are subscribed to the Google Groups "sci.electronics.repair"
group.

To post to this group, visit http://groups.google.com/group/sci.electronics.repair?hl=en

To unsubscribe from this group, send email to sci.electronics.repair+unsubscribe@googlegroups.com

To change the way you get mail from this group, visit:
http://groups.google.com/group/sci.electronics.repair/subscribe?hl=en

To report abuse, send email explaining the problem to abuse@googlegroups.com

==============================================================================
Google Groups: http://groups.google.com/?hl=en

Electronics

sci.electronics.repair - 19 new messages in 8 topics - digest

No Response to "sci.electronics.repair - 19 new messages in 8 topics - digest"

Post a Comment

Blog Roll

Blog Archive