Digest for sci.electronics.repair@googlegroups.com - 18 updates in 8 topics

KenO <kenitholson@yahoo.com>: Aug 18 09:38AM -0700

ohg,
 
"Don't overthink this. This is simply a bridge bypass cap, not a PFC filter."
 
Am trying to use this as a learning experience.
 
I have a hard time believing that Samsung would continue to use poor quality caps in their LED TVs.
 
Instead am wondering if the Samsung BN44-00554B is a poor design? If this is correct then the 47uF 160 V 105 C cap should be upgraded. My problem is I have No knowledge or experience in this area, which is why am asking for suggestions.
 
Do you know if the schematic is available on line?
 
Thanks again for your help!
ksroopa123456@gmail.com: Aug 18 05:21AM -0700

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Aardvarks <aardvarks@a.b.c.com>: Aug 14 02:16AM

On Thu, 11 Aug 2016 13:45:14 -0400, nospam wrote:
 
>> In fact, there is almost nothing that you can do with payware that you
>> can't do with freeware.
 
> bullshit.
 
While there are things that exist only in payware, name a function that you
can do only with payware that I can't do with freeware.
 
I'm one of the most reasonable men alive - if you can name a functionality
that you have with payware that I care about having with freeware - I'll
already have the freeware to do it.
 
However, if I want to do it - and if I can't do it with freeware, then I'll
agree with you - but you just always say "bullshit" without backing up any
of your claims.
 
You never back up your claims.
crankypuss <undisclosedUserid@gmail.com>: Aug 12 09:39AM -0600

On 08/11/2016 01:05 PM, Aardvarks wrote:
> Q: Without logging into anything, and without any google accounts, how is
> running a non-Google app offline going to tell Google anything?
 
If you don't want google able to peek into your life, you also need to
not use google search, and not visit any websites that use google ad
services, and not do a whole bunch of other stuff, which you largely
can't avoid because when you visit some arbitrary website with a link to
some other arbitrary website, there's no telling in advance what
services any of them are using.
 
nospam's comment about not using google operating systems is mostly
spot-on, except that just about every maker (possible exceptions that I
know of being Moto and OnePlus) slams their own crapware into/onto
Android before it goes on your phone, and some might remove stuff Google
put there, but the bottom line is this: your OS is a crapshoot, unless
you personally review every line of code in the thing, you're trusting
someone, and the manufacturer (who orders the hardware from China)
doesn't give you the full source code for exactly whatever might be
installed on your phone by the time you gain possession of it.
 
You're in search of perfection. It's mostly been legislated out of the
realm of possibility due to cutthroat economic competition and a
consumer demographic that reads "mostly housewives and their hubbies or
their kids", ie "*not* computing professionals". If you really value
perfection, you'll find some way to facilitate it other than pissing off
potential friends by continually ranting about things that are totally
messed up; I know this from having been there. Put a cap over your rant
buttons, justified as they may be; remain in the part of the real world
that other people give a shit about, which clearly is not perfection:
Nobby Nobbs wouldn't know perfection if it bit him on the ass, and
probably half the readership here never heard of Nobby to begin with.
 
Paranoia is a good thing in a system security architect, but as a
consumer you're just pissing in the wind. So if you want perfection,
make your own. If you want to avoid people snooping into your real
life, don't ever enter a true fact about your life into any computer
anywhere. Good luck with that, it's about as useful as turning off
javascript (which imo is a low form of primordial excreta).
 
This is Earth, the world is fucked-up here, get used to it.
 
--
http://totally-portable-software.blogspot.com
[Sat Mar 26: "Documentation and Portability"]
crankypuss <undisclosedUserid@gmail.com>: Aug 12 09:08AM -0600

On 08/11/2016 02:24 PM, The Real Bev wrote:
> on the theory that either I'll want them instantaneously ("Find my car"
> or I use them so often (ES File Explorer) that I don't want to waste
> extra taps or brain-pixels.
 
I just put my most-frequently-used apps in the easiest-to-get-to place,
and when something gets used often enough to make accessing it an
annoyance, I promote it to an easier-to-access position. Duh?
 
--
http://totally-portable-software.blogspot.com
[Sat Mar 26: "Documentation and Portability"]
N_Cook <diverse@tcp.co.uk>: Aug 13 01:58PM +0100

The Tx came out easy enough, as did the outer layer of paper, after
warming with hot air, so cannot have been that cooked.
Frame and wires to each other showed nothing to 30M on DVM-R or to 20G
on megger.
Enamel of outer 6.6V,6A winding looks fine, but blacker paper under that
layer. No sign of any tar, looks as though it is beeswax? , looks like
whatever the yellowish wax that was covered on those notoriously leaky
waxed paper caps, its that which has carbonised to black tar-like
material probably, and flowed out of the Tx. No cloth seen in lower
layer either, seems paper and wax. Over about 2mm of ome of the wax/tar
on the inside of the removed paper, got a Megger reading of 5G.
I'm assuming a distributed "carbon resistor " over a large area (to
distribute .5KW of heat) rather than shorted turns as at no point has
there been any of that nasty magnetisation buzz of shorted turns.
How to determine if the "resistor" is on the primary, nearest core so
hottest, or the HT secondary winding?, unlikely the high amp windings.
Nothing to loose placing the Tx on a tray in a low oven, but which
orientation, as in normal use or the other way up and hope enough wax
flows out. It would be nice to take some before and after ohms reading
of something , if anyone has any ideas.? Leaves the possibility of near
enough solid carbon at the main hotspot, that will not budge at all.
You'd think after decades at this game you'd have seen all possible
fault scenarios.
N_Cook <diverse@tcp.co.uk>: Aug 13 02:33PM +0100

I just thought , take R and L readings with a RLC meter, for the
sections of primary (assuming same gauge of wire through the length) and
2 sections of HT secondary and they should be proportionate, R to L of
each section. Then retake readings after heating.
BTW I rechecked the Tx ,after removal, on variac
N_Cook <diverse@tcp.co.uk>: Aug 12 12:28PM +0100

Tried on 115V selector setting at about 20% (UK) mains and current draw
went up to about what it was with 50% of UK mains on 245V setting.
IR thermo showed the Tx was warming up nicely even at 20% of 240V main,
current too low on variac ammeter to measure but .2 to .4 A ac.
I wonder how hot this Tx got , presumably in hours of use, stinking the
place out with tar smell (noticeable at just 10 deg C over ambient),
before it was stored away?
 
Anyway trying a bit of the tar on DVM-R, squashing the probes together
over a bit of it, perhaps about 0.2mm thick, could get a few megohm.
Trying on a megger over a 1mm or 2, easily got 500M to 1G. So has anyone
ever tried removing one of these Tx and baking in a low oven , outdoors
presumably, to drain liquid tar out, then replace it with what ?.
I'll disconnect all the wires and see if there is a pair of points I can
measure with a Megger, if any of the team think its worth trying in an
oven or other ideas?
Conductive resistor path inside would explain the linear characteristic
of the excess current , but primary , secondary? With Tx removed I can
check inter winding leakage and to frame,screen etc
With Tx removed, would it be worth removing the outer cooked paper and
underlying cloth to get a closer look at the windings, perhaps tar is
just leeched from the cloth originally (for anti-damp purposes and not
holding windings in place? Where to research Tx construction of the 1960s?
The owner said that while it was working properly last week and the
start of the arcing/sparking noise , before switching off,there was a
puff of what he called steam rather than smoke, before switching off.
Perhaps related to damp or fried insect and nothing to do with the tar
resistor problem. I've not had anywhere near full HT on this amp.
 
Valve rectifier, not SS, BTW
N_Cook <diverse@tcp.co.uk>: Aug 12 07:21PM +0100

Hang on a bit , a quote on submarine cable manufacture
"Two layers of coal tar-impregnated jute over the armor wires complete
the cable structure."
N_Cook <diverse@tcp.co.uk>: Aug 12 02:30PM +0100

If paper burns at 451 deg F, what temp for near to charring, the voltage
& current ratings are just about readable with the right light on the
Tx, as black print on now almost black grade of brown paper, colour
maybe partly due to tar vapour of course
Andy Burns <usenet@andyburns.uk>: Aug 14 08:33AM +0100


> there are some ICs they can make a fortune on, for example the
> Technics STKSVI ones. Talk a hundred bucks apiece. These days, don't
> count on getting any good STK anything.
 
Hmmm, did I put my old SU-V4X in the loft, or chuck it in a skip?
"Snuffy \"Hub Cap\" McKinney" <Snuffy-Hub-Cap@Livebait-McKinney.com>: Aug 12 01:40PM -0700

Sorry folks. Big disappointment here. I fell for the old "best shower in decades" trick.
 
"Snuffy "Hub Cap" McKinney" <Snuffy-Hub-Cap@Livebait-McKinney.com> wrote in message news:Wa2dncahda19KzHKnZ2dnUU7-LnNnZ2d@earthlink.com...
Fellow tinkerers....this one is supposed to have twice as many as normal.
The story is that the best time is after midnight, after the moon goes down. Best way is to lie flat on a lawn chair with a nice tall drink in one hand, face the northeast and look about 2/3 of the way up and try not to fall asleep.
 
http://www.npr.org/sections/thetwo-way/2016/08/10/489491194/this-years-perseid-meteor-shower-is-going-to-be-quite-a-show-heres-how-to-watch
 
Or watch the live stream....
http://www.ustream.tv/channel/nasa-msfc
"J.B. Wood" <arl_123234@hotmail.com>: Aug 12 07:04AM -0400

On 08/11/2016 10:53 PM, Ron D. wrote:
 
> phone connected but off hook. I forget the magic mumbers your
> looking for. I think it's a few megohms max.
 
> If overhead lines, then spiders in the box there too.
 
Hello, and no DSL. The rest of your points make technical sense. My
ca. early 1940s apartment building has a large grey wall-mounted W-E/Ma
Bell box in the laundry room with a punch-down terminal strip. The
house wiring from these terminals to units isn't the traditional
sheathed red-green-yellow-black but simply twisted pair (IOW just tip
and ring) like that used to connect to the outside plant. The
connections from the wall-mounted terminals in my unit and the
corresponding incoming phone line wires appear to be firmly punched-down
in the W-E terminal strip.
 
So, except for access to the laundry room terminal block and the
terminals in my unit there's really nothing else I can check either on
the outside of the building or elsewhere (which should be Verizon's
responsibility). Sincerely,
 
--
J. B. Wood e-mail: arl_123234@hotmail.com
dplatt@coop.radagast.org (Dave Platt): Aug 12 11:16AM -0700

In article <nokagk$u7p$2@gioia.aioe.org>,
>terminals in my unit there's really nothing else I can check either on
>the outside of the building or elsewhere (which should be Verizon's
>responsibility).
 
"Laundry room" rings a bell with me.
 
In a house we rented some decades ago, we had problems with line noise
on the phone, ring failures (the caller would hear a ring tone and
then an immediate disconnect) and other problems.
 
The problem turned out to be laundry-related, in a way. The line came
into the house in the kitchen, and was wired to one of the square
four-terminal line blocks before running up the wall to the phone.
This was located right next to the clothes washer.
 
It turned out that over the years, dirt and spiderwebs (and maybe some
soap dust) had gotten into the connection block, and build up on the
surfaces. When humidity was high (e.g. when we were doing laundry
with hot water) and the surfaces were cold (e.g. winter) moist air
would cause condensation inside the connection block, dampening the
surface contamination and creating a current leakage path.
 
It was bad enough that when the phone would try to ring for an
incoming call, enough current would flow to momentarily trigger the
central office's "off hook" detector, and the call would be
"answered"... and then drop out immediately.
 
The cure was straightforward: pop off the connection-block cover,
dust it out, scrub everything with a soft brush and some denatured
alcohol to remove the contaminants, dry thoroughly, close back up.
Problem gone.
 
I once had a similar problem, in which house moisture condensing
inside a Macintosh keyboard in a cold room would bridge the ADB "power
button" signal lines enough to cause the Mac to power itself on.
Cleaning and drying the PC board in that area, and then dabbing on a
thin layer of fingernail polish as a "conformal coating" fixed the
problem.
 
So, it might be worth checking your inside wiring and phones for any
places where cross-wire current leakage might occur. Clean, dry, and
if possible insulate against further contamination and moisture.
"Ron D." <Ron.Dozier@gmail.com>: Aug 17 09:51AM -0700

If outside air is used and say the temp is 90 outside, you only get say 75 deg degree air no matter what.
 
Why would this affect what I said? The air would be 75 on low speed,
but on higher speeds it would blow by the evaporator so fast it
wouldn't cool as much.
- hide quoted text -
 
Air temperature should really stay the same, BUT the perceived coldness should change. Take a 70 degree day with no breeze vs a 70 degree day with a 15 mph breeze. In the latter, people are cooled by the increased evaporation on their skin.
 
Fan speed MIGHT make a difference depending on the design, but you really want the evaporator to be just above freezing. With some range of air velocity, the outlet temp won't really change.
"Ron D." <Ron.Dozier@gmail.com>: Aug 17 09:58AM -0700

But the compressor never got shut off, and the AC is fully charged and
not subject to freezing, and most importantly I can run in any of
those 3 speeds for a long time and nothing changes.
 
--
 
You really need to do a "performance test" which is basically open the doors, run on outside air and measure the incoming temp/humidity (Use weather bureau for humidity) and discharge temps.
 
You should get between 15 and 20 degree difference in temperature. A lower difference, if the humidity is high.
 
The compressor really should never shut off in a more modern vehicle unless the evaporator is in danger of freezing. Freezing is possible if your using the AC when it's 40 degrees outside, which I frequently do.
Tim R <timothy42b@aol.com>: Aug 17 11:24AM -0700

On Wednesday, August 17, 2016 at 12:58:54 PM UTC-4, Ron D. wrote:
 
> You really need to do a "performance test" which is basically open the doors, run on outside air and measure the incoming temp/humidity (Use weather bureau for humidity) and discharge temps.
 
> You should get between 15 and 20 degree difference in temperature. A lower difference, if the humidity is high.
 
> The compressor really should never shut off in a more modern vehicle unless the evaporator is in danger of freezing. Freezing is possible if your using the AC when it's 40 degrees outside, which I frequently do.
 
Defrost always runs the compressor though, so in the winter everybody uses it. At least in cars I've had.
avagadro7@gmail.com: Aug 17 04:53PM -0700

NO RECIRCULATE
 
recirculate is for a load of rotting fish.
 
https://www.google.com/search?site=imghp&tbm=isch&source=hp&biw=1791&bih=900&q=toyota+corolla+air+conditioning+system&oq=toyota+air+conditioning+system&gs_l=img.1.1.0i8i30k1l5j0i24k1l2.1933.11761.0.17238.30.28.0.2.2.0.323.3123.7j19j0j1.27.0....0...1ac.1.64.img..1.29.3129...0j0i30k1.gjR2pH0hJY0
 
more air moving over an operating exchanger gives cooler temps...otherwise the system needs repair.
 
try wiring the fan directly to the battery with a relay. prob the ground side.
 
first check for leaks in the output side n close down vents not needed.
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