Digest for sci.electronics.repair@googlegroups.com - 25 updates in 7 topics

Anda Lucite <andalucite@andalucite.net>: Feb 22 12:11AM

Whiskers wrote in message
slrnncjit5.qb.catwheezel@ID-107770.user.individual.net
 
 
> there may already be a 'build' of the tarball for your distro (possibly
> in the 'testing' or 'user-contributed' or other 'unofficial'
> repositories).
 
Thanks Whiskers for figuring out how to finally list all the devices
on the network from the desktop/laptop computer.
https://www.fingbox.com/download
 
This worked:
$ wget "https://www.fingbox.com/download?plat=lx64&ext=deb"
$ mv "download?plat=lx64&ext=deb" fing_lx64.deb
$ sudo dpkg -i ./fing_lx64.deb
$ sudo fing -n 192.168.1.0/24 -r 1
 
Here is the result on the unrooted mobile phone:
https://i.imgur.com/XsnyHJx.gif
 
Here is the result on the desktop/laptop:
---------------------------------------------------------------
| State | Host | MAC Address | Last change |
|-------------------------------------------------------------|
| UP | 192.168.1.1 | 84:1B:5E:CC:A3:FF | |
| UP | 192.168.1.2 | 5C:0A:5B:C4:22:51 | |
| UP | 192.168.1.3 | 00:18:61:00:A4:CE | |
| UP | 192.168.1.4 | 00:1F:3B:AA:D0:4A | |
| UP | 192.168.1.5 | 40:B0:FA:88:33:A1 | |
| UP | 192.168.1.8 | 40:B0:FA:88:33:A1 | |
| UP | 192.168.1.9 | F8:D0:AC:DD:5A:FF | |
| UP | 192.168.1.10 | 00:14:22:FF:56:31 | |
| UP | 192.168.1.11 | 00:80:05:AA:43:55 | |
| UP | 192.168.1.116 | 00:10:83:00:8A:FF | |
| UP | 192.168.1.200 | 00:16:B6:53:66:91 | |
---------------------------------------------------------------
 
These failed to report *all* devices (hence they're useless):
$ sudo netdiscover -i wlan0 -r 192.168.1.0/24
$ sudo arp-scan --interface=wlan0 --localnet
 
Now we finally have a way to list *all* the devices on the network!
William Unruh <unruh@invalid.ca>: Feb 22 12:13AM

> $ sudo netdiscover -i wlan0 -r 192.168.1.0/24
> $ sudo arp-scan --interface=wlan0 --localnet
 
> Now we finally have a way to list *all* the devices on the network!
 
Of course it is also a closed source program, as far as I can see, so
for all we know, it reports all those devices back "home"
Dimitrij Klingbeil <nospam@no-address.com>: Feb 21 06:27PM +0100

On 20.02.2016 15:36, JC wrote:
> ... In one of your pictures there are a couple of diodes that look
> messed up (V1809 and V1811) near the bridge. They are supposed to be
> BY208-1000 (1000v rectifiers), I can see "40" on one, maybe 1N4007?
 
Well, if that is true then beware! V1808, V1809 and V1811 are supposed
to be very fast. Any slow (more than a microsecond) diode in these
positions will likely cause symptoms akin to a heavy overload.
 
Particularly V1811, if replaced with any 1N400x, is likely to render the
energy recovery circuit around L1806 as good as inoperative, thereby
dumping the entire energy from the switcher harmonics into R1814, which
will cause it to overheat fast.
 
Please recheck L1806 (both windings) for turn-to-turn shorts (with a
signal generator), and if any of the 3 diodes (V1808, V1809, V1811)
looks like it had previously been replaced (possibly improperly
replaced), consider replacing all 3 of them together, using the proper
parts.
 
Use fast soft-recovery diodes rated for 1kV here. If you can't find any,
use ultrafast ones. They're maybe not optimal from an EMI standpoint
here, but at least they should work well enough for testing.
 
If you can't find a BY208-1000 replacement, a MUR4100E should work.
 
Check C1806 for dielectric breakdown. It should be able to withstand at
least 500 V (or something in that ballpark). If it doesn't, replace.
 
Don't underestimate that L1806 energy recovery circuit. Although it
doesn't by itself transfer any power to the load, this supply heavily
relies on it for proper resonant operation of the main transformer. It
must be working properly before you can test the main transformer
waveform and have any chance of making correct measurements.
 
Besides, your description of heavy switching noise on V1806 (when you
tried to measure the base drive waveform), up to the point of the
waveform being unrecognizable in the noise, seems to indicate that the
L1806 circuit is shorted at high frequencies. This can be a result of
either a winding short in L1806 or a breakdown in one of its diodes or
some of these diodes being replaced by a generic slow silicon diode.
 
Dimitrij
Dimitrij Klingbeil <nospam@no-address.com>: Feb 21 07:36PM +0100

On 20.02.2016 13:55, Cursitor Doom wrote:
> 0.17ohms, 0.26ohms, 0.28ohms, 3.7ohms, 3.8ohms. So this doesn't seem
> to tally up with the schematic. Or does it? I need a pint of strong
> coffee to kick-start my head on this one. :-/ Anyway, later...
 
Hi
 
As you say, this really doesn't tally up. The ratios look ok (see my
other post), but the absolute values are obviously junk.
 
After all, Ohm's law still holds, even for reactive impedances, and 60
volts divided by 3.7 Ohms is 16 amps, which would be WAY too much for a
small transformer winding's magnetization current. That would indicate
very heavy overload, most probably due to a short circuit inside one of
the windings.
 
But there's something that makes me distrust those impedance numbers -
and that is your use of 100 kHz as the testing frequency.
 
First of all, did you really use 100 kHz as written? Most LCR meters
have 100 Hz, 1 kHz, 10 kHz and 100 kHz signals. Did you perchance use
the 100 Hz one instead? 100 Hz would be so low that the inductive part
might not even register properly.
 
Second, 100 kHz is not a good choice. The reason for this is the
self-resonance frequency (SRF) of your transformer. All coils and
transformers in the real world are not just coils, but LC circuits. The
L part is (obviously) provided by the winding itself and the C part is
the stray capacitance between the wires in the winding. Being really an
LC circuit, a winding has a resonance frequency, like any "true" LC
circuit would have. This is called the SRF of the winding. To make
matters worse, a transformer that has multiple windings wound with
different geometries and wire diameters has multiple SRFs, one for each
winding.
 
Windings with few turns of loosely packed thick wire have high SRF
values, while windings with many turns of densely packed thin wire will
have much lower SRFs.
 
Your particular transformer has 2 high-voltage windings for the kV
outputs. They have lots of densely packed thin wire, so their SRFs will
be very low. I don't know exactly how low, but I'm sure that they will
be much lower than 100 kHz, and that's what makes 100 kHz an unsuitable
choice for testing.
 
If fact, if you try to operate a winding above its SRF (let's say the
winding has a 20 kHz SRF and you try to apply 100 kHz), then the winding
will no longer behave like an inductor, but it will behave like a
capacitor instead. I know, this seems crazy, but that's how a winding
behaves above its SRF.
 
In a transformer, where there are multiple windings, there are also
multiple SRFs, so at some test frequency, some windings may happen to be
below their respective SRFs, while some other windings may be above
their respective SRFs, depending on how you choose the test frequency.
 
If any winding happens to be above its SRF, then it will behave like a
capacitor. As you know, capacitors behave more or less like a short
circuit at high frequencies, and an above-SRF winding will behave like
that too. That is, it will look (from an impedance measurement) like if
it was heavily overloaded or even shorted out altogether.
 
So your 100 kHz measurements indicated very low impedances, like some
winding was shorted out. But then you also have 2 high voltage windings
in there, which would have been way above SRF at 100 kHz frequency, so
they will effectively behave like shorted even if they were perfectly
fine otherwise. At 100 kHz they're no longer inductors, they're likely
just capacitors instead.
 
Now, to test transformer winding impedances, you need to select a
reasonable test frequency. It must obviously be lower than any SRF of
any winding - otherwise the transformer will appear overloaded. If you
don't know the SRFs' values, you can measure them out with a signal
generator and an oscilloscope. But you don't need to. Normally no
transformer is operated above its SRF (it would not work very well if
one tried), so you can assume the normally intended frequency of
operation to be a "safe" choice that is unlikely to hit SRF limits.
 
Your transformer is probably supposed to run at something like 20 kHz in
normal resonant operation, so 20 kHz should be ok. But because it has
high voltage windings, it may be very close to the HV winding's SRF.
Indeed Philips engineers may even have chosen to run the transformer not
below, but essentially right at SRF. They may have selected the
resonance capacitors for the primary in such a way that the primary
(together with the resonance capacitors) would have a resonant frequency
which closely matches the self-resonance of one of the high voltage
windings, being just a little bit below to account for tolerances.
 
If that's the case, you should use a lower frequency for testing
impedances. Most LCR meters don't offer 20 kHz anyway, just 10 kHz and
100 kHz as "nearest neighbors". 100 kHz won't do, so use 10 kHz. That
should give you realistic impedances (which you can manually multiply by
2 to get to the in-circuit conditions).
 
Regards
Dimitrij
Dimitrij Klingbeil <nospam@no-address.com>: Feb 21 08:09PM +0100

On 21.02.2016 18:27, Dimitrij Klingbeil wrote:
>> 1N4007?
 
> If you can't find a BY208-1000 replacement, a MUR4100E(G) should
> work.
 
Sorry, that may be physically too big to fit. A MUR1100EG or something
similar should work and fit in the available space too.
 
Dimitrij
Cursitor Doom <curd@notformail.com>: Feb 21 08:46PM

On Sun, 21 Feb 2016 19:36:29 +0100, Dimitrij Klingbeil wrote:
 
[...]
 
> have 100 Hz, 1 kHz, 10 kHz and 100 kHz signals. Did you perchance use
> the 100 Hz one instead? 100 Hz would be so low that the inductive part
> might not even register properly.
 
Yes, definitely 100kHz. Not my preferred choice, but the only option
given the meter I used which was actually a capacitor ESR meter.
 
[SRF remarks noted]
> they will effectively behave like shorted even if they were perfectly
> fine otherwise. At 100 kHz they're no longer inductors, they're likely
> just capacitors instead.
 
Very good point. I admit I never considered that possibility.
 
> 100 kHz as "nearest neighbors". 100 kHz won't do, so use 10 kHz. That
> should give you realistic impedances (which you can manually multiply by
> 2 to get to the in-circuit conditions).
 
Yes, it might be illuminating to sweep a range of frequencies and note
any resonances, I can see the value of that. Unfortunately, an LCR meter
is one item of test equipment I don't have, so it would have to be sig
gen and scope in combination. Anyway, it's do-able.
Many thanks for your observations as always.
Cursitor Doom <curd@notformail.com>: Feb 21 08:59PM

On Sun, 21 Feb 2016 20:09:47 +0100, Dimitrij Klingbeil wrote:
 
 
> Sorry, that may be physically too big to fit. A MUR1100EG or something
> similar should work and fit in the available space too.
 
> Dimitrij
 
Thank you. If you've had the chance to read my follow up to JC (I think
it was) then you'll be aware that one of those BY208 diodes was replaced
by a BY134. If the design is that critical of the speed of the diodes it
uses then maybe it won't function properly as you suggest. I can only
imagine the technician who replaced it was unaware of the critical nature
of the part concerned.
I'm kind of unhappy with this design overall, to be honest. It was
critically appraised on s.e.d and found generally unsatisfactory. I'm
strongly tempted to just save the transformers, junk everything else and
start afresh with a modern design. The rest of the scope is mint and
untouched, it's only the psu section that's been butchered around and
shows signs of burning and scorching in places. Maybe the best thing to
do would be to bin it? :-/
JC <Chipbee40_SpamNo@yahoo.com>: Feb 21 04:28PM -0500

On 2/21/2016 3:59 PM, Cursitor Doom wrote:
> untouched, it's only the psu section that's been butchered around and
> shows signs of burning and scorching in places. Maybe the best thing to
> do would be to bin it? :-/
 
Switching supplies are all designed with the diode (and other component)
parameters in mind, its how they function efficiently. Bunging any old
diode in is asking for trouble. Same as the ESR and temp rating of the
caps used. Seriously you need to sit back and chill. These scopes were
very well designed and I would say exceptionally reliable. I'd like to
see you build a replacement. I've designed switching supplies,
everything needs to be right or it goes wrong fast.
 
FR107G seems to be the current equivalent for the BY208-1000
JC <Chipbee40_SpamNo@yahoo.com>: Feb 21 05:13PM -0500

On 2/21/2016 4:28 PM, JC wrote:
> see you build a replacement. I've designed switching supplies,
> everything needs to be right or it goes wrong fast.
 
> FR107G seems to be the current equivalent for the BY208-1000
 
FR107G Ebay (UK) #390565307743 cheap enough.
Cursitor Doom <curd@notformail.com>: Feb 21 10:15PM

On Sun, 21 Feb 2016 16:28:50 -0500, JC wrote:
 
> see you build a replacement. I've designed switching supplies,
> everything needs to be right or it goes wrong fast.
 
> FR107G seems to be the current equivalent for the BY208-1000
 
Well, the modern ones may well be super reliable, but this old thing is
very dated and shows many signs of its age and the scars of previous
faults and questionable repairs. I wouldn't attempt another resonant
converter; there must be something simpler with fewer critical
parameters, surely.
Cursitor Doom <curd@notformail.com>: Feb 21 10:36PM

On Sun, 21 Feb 2016 17:13:55 -0500, JC wrote:
 
>> everything needs to be right or it goes wrong fast.
 
>> FR107G seems to be the current equivalent for the BY208-1000
 
> FR107G Ebay (UK) #390565307743 cheap enough.
 
Thank you, JC. You and Dimitrij have both given me some subs for suitable
replacements which I'm quite happy to go along with. But I'm not prepared
to spend much more time on this repair, to be honest. I'd relish the
prospect of a comprehensive re-design. Even if it's beyond me at this
stage I'd learn a lot from it.
Dimitrij Klingbeil <nospam@no-address.com>: Feb 22 12:52AM +0100

On 21.02.2016 21:59, Cursitor Doom wrote:
> untouched, it's only the psu section that's been butchered around and
> shows signs of burning and scorching in places. Maybe the best thing
> to do would be to bin it? :-/
 
Hi
 
As for the BY134, sorry, I must have overlooked that somehow, or maybe
it did not register in my memory right away. Anyway, it's just as bad a
choice as a 1N4007 and its ilk. It's designed for mains rectification
and doesn't even make an attempt at being fast.
 
No use in an active snubber or energy recovery circuit whose task it is
to "strip out" the high frequency components from a square wave.
 
Get rid of it, and while you're at it, consider the condition of the
other two (V1808+9) identical ones. Sometimes a person who does an
improper repair will try swapping nearby components hoping that another
one might be "less critical". So if you see signs of unprofessional
manual soldering on them, take that whole trinity and replace them.
 
Same with C1806. If it looks suspicious, does not pass a withstand test
at some 105% of its rated voltage or shows high ESR, change it too.
 
BY208-1000s are hard to come by nowadays, so here is a list of some more
modern candidates: MUR1100E, BYV26E, UF4007. They should fit, and even
though they are faster than the original BY208-1000, they should work.
 
There are also: RGP30M (slightly large, modest speed), UF5408 (slightly
large), MUR4100E (slightly large), STTH112U (smd), US1M (smd) BYG23M
(smd). They may or may not fit due to size and space constraints, and
the SMD ones would likely need some wire leads soldered on (won't look
professional, but hey, if others are too hard to come by, that's ok).
 
Once you've fixed that botched repair on the energy recovery circuit,
connect a taillight lamp to the 12.7 V output, test it again and tell
your results here (make sure you put all the proper parts back in,
before you switch it on, this supply may be unforgiving if any parts
are missing and it's powered on).
 
As for the design being "generally unsatisfactory", let me disagree.
Resonant converters do have a well earned place in the world of power
electronics, but the design of them is, in a way, a black art. They have
lots of pitfalls for the unwary and not so many engineers can actually
design them properly and they tend to use special components (inductive
ones in particular) that would be rather unsuitable for other topologies
too. Yet they do have certain benefits, low noise operation that is
suitable for sensitive measurement instruments, being one of them. They
are not so easy to understand, compared to "simple" flyback topology
supplies - so people go screaming "this is too complex" or "this uses
too many parts". In fact your supply's energy recovery circuit is
actually a little unregulated flyback converter of its own! But so far
(and considering the design's day and age), all the parts that I've seen
in that schematic seem to me to have a good reason for their existence.
 
Greetings
Dimitrij
"Andy Wood" <woodag@trap.ozemail.com.au>: Feb 22 07:03AM +1100

"Clifford Heath" wrote in message news:a4dyy.9156$Nf2.4984@fx14.iad...
 
. . .
 
>is coated with something very slick, perhaps PTFE. The thermo switch is
>just an on-off bi-metal thing that rides against the fuser tube - with
>surprisingly little signs of wear on the ones I took apart.
 
When I got "fuser error" on an ancient mono HP Laserjet, I also found that
fusers were expensive, although I did also turn up some place that sold
replacement heating elements. For that model, there was a ceramic element
and a thermistor in the fuser.
 
However, my tests and measurements showed no obvious problem with the fuser
and I came to the conclusion that the problem was in the controller board. I
established that power was getting supplied to the heater, but ended up
replacing the control board with one from another printer which itself was
actually working but had seen a lot more use than the first one.
 
For the record, the repaired Laserjet still works today - it is way over 20
years old now.
Jeff Liebermann <jeffl@cruzio.com>: Feb 21 12:16PM -0800

On Sun, 21 Feb 2016 17:22:31 +1100, Trevor Wilson
 
>* Service data source?
 
<http://www.FixYourOwnPrinter.com>
<http://www.fixyourownprinter.com/?printer_brand=9&printer_series=61&printer=1988&Search=Search>
<http://support.hp.com/us-en/product/HP-Color-LaserJet-3000-Printer-series/501044/model/501046/manuals>
<http://www.PrinterWorks.com>
<http://www.lbrty.com>
<http://partsurfer.hp.com>
<http://partsurfer.hp.com/Search.aspx?type=PROD&SearchText=Q5987A>
 
Service Manual:
<http://support.hp.com/us-en/product/HP-Color-LaserJet-3000-Printer-series/501044/model/501046/manuals>
There are also dealers on eBay selling manuals on CD or download.
 
>* Can the fuser be repaired? The cost of a fuser here in Australia is
>astronomical?
 
Yes, it can be repaired with a rebuild kit.
<http://www.ebay.com/sch/i.html?_nkw=hp+color+laserjet+fuser+rebuild>
The rebuild kits do NOT include a heater and are therefore indpendent
of line voltage. If you've never done it before and/or lack specific
instructions, I suggest you go for a rebuild or exchange fuser
instead.
 
<http://h20564.www2.hp.com/hpsc/doc/public/display?docId=emr_na-c00508146>
For 220VAC the fuser PN is RM1-2743-000
For 117VAC the fuser PN is RM1-2665-000
 
>* Is the fuser a 230VAC one (Australia is a 230VAC nation), or can I
>just buy a new fuser (or re-built one) from eBay?
 
That's NOT an either-or type choice. Yes, you can buy a rebuilt fuser
on eBay, but it has to be 220VAC type for AU.
 
>* I assume there is some kind of feedback system (NTC or PTC element)
>and that is what has failed, rather than the heater (the fuser still
>gets hot)?
 
If the temperature sensing circuit has had a failure, you'll get an
error message on the display during boot up. There is also an
overtemp thermostat to prevent meltdown.
 
The usual failures that I see are hardened toner buildup on the
fingers that peel the paper away from the fuser roller, a fried fuser
film sleeve, and worn gear teeth.
 
>Any suggestions will be welcome. After spending almost 300 Bucks on
>toner, I am keen to keep this sucker going for another few years. I'd
>prefer not to spend 500 Bucks on a new fuser though.
 
$500 for a fuser is far too much.
<http://www.amazon.com/s/?ie=UTF8&keywords=hp+3600n+fuser>
No clue about AU prices. For 220VAC, email the vendor. Most
rebuilders carry both voltages or can possibly swap out the heater
element.
--
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
Trevor Wilson <trevor@SPAMBLOCKrageaudio.com.au>: Feb 22 07:56AM +1100

On 22/02/2016 7:16 AM, Jeff Liebermann wrote:
> No clue about AU prices. For 220VAC, email the vendor. Most
> rebuilders carry both voltages or can possibly swap out the heater
> element.
 
**Awesome! Thanks for the info and the links.
 
--
Trevor Wilson
www.rageaudio.com.au
 
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"Kenny" <me@privacy.net>: Feb 21 09:21PM

"Trevor Wilson" wrote in message news:diumjqFccshU1@mid.individual.net...
 
On 22/02/2016 7:16 AM, Jeff Liebermann wrote:
> No clue about AU prices. For 220VAC, email the vendor. Most
> rebuilders carry both voltages or can possibly swap out the heater
> element.
 
**Awesome! Thanks for the info and the links.
 
--
Trevor Wilson
www.rageaudio.com.au
 
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Hope this helps:
http://ridl.cfd.rit.edu/products/manuals/HP/HP_LaserJet_3000_3600_3800_Series_Service_Manual.pdf
 
Kenny Cargill
Trevor Wilson <trevor@SPAMBLOCKrageaudio.com.au>: Feb 22 10:05AM +1100

On 22/02/2016 7:16 AM, Jeff Liebermann wrote:
> No clue about AU prices. For 220VAC, email the vendor. Most
> rebuilders carry both voltages or can possibly swap out the heater
> element.
 
**Looks like my only solution is this:
 
* Buy a replacement fuser and hope that is the only fault. Cost will
exceed AUS$300.00.
* Buy a new printer. I found a multifunction device from HP, which would
do the job. Model MFP M177FW. RRP AUS$329.00. For a few more Bucks
(about AUS$300.00), I could buy a Dell C2665dnf. Thoughts?
 
There's a Samsung in the mix, but I purchased a Samsung a couple of
years back. Atrocious POS. A simple paper jam would typically take 30
mins to clear. After owning 4 HP printers, I have always found that
paper jams are quickly and easily cleared. I a leaning towards HP for
that reason.
 
--
Trevor Wilson
www.rageaudio.com.au
 
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Jon Elson <elson@pico-systems.com>: Feb 21 05:32PM -0600

Trevor Wilson wrote:
 
> * I assume there is some kind of feedback system (NTC or PTC element)
> and that is what has failed, rather than the heater (the fuser still
> gets hot)?
 
Ok, if the fuser heater is still working, then find the sensor (there will
usually be two, a control thermostat and a safety thermostat). Trace the
wires back to whatever board controls the fuser, and reseat the connectors.
That may fix it. If not, pull that board and look for crumbling solder
joints on the connectors. If nothing there, then dismantle the fuser and
check that the sensors still have contact with the fuser roller, aren't
covered in melted toner, etc. Then, you have to decide whther to replace
the sensors or the control board.
 
And, the most awesome resource is :
http://www.fixyourownprinter.com/
 
They have discussions and instruction on how to fix all sorts of problems.
 
Jon
"Tim Williams" <tiwill@seventransistorlabs.com>: Feb 21 01:31PM -0600

You're doing it wrong: never wait for dry metal to melt solder opposite the
iron. Tin under the iron, so there's thermal transfer. Then go around the
braid, spreading the tinned area around it. Mind the core will melt to goo
while you're doing this...
 
And as others have mentioned, if it's aluminum or stainless, you're screwed.
 
Tim
 
--
Seven Transistor Labs, LLC
Electrical Engineering Consultation and Contract Design
Website: http://seventransistorlabs.com
 
"Steve" <loft@centurylink.net> wrote in message
news:87egc65xql.fsf@centurylink.net...
John G <john.g@green.com>: Feb 22 10:06AM +1100

Ralph Mowery expressed precisely :
 
>> That just sounds like another excuse to the use the butane torch :)
 
> Most of the rg-6 uses aluminum instead of copper or tinned copper. The
> normal methods of soldering will not work on it.
 
I'll believe Aluminium or steel I must admit to only a little actual
experience.
Some Cable guy should give an actual answer.
 
--
John G Sydney.
hrhofmann@att.net: Feb 21 02:43PM -0800

I took apart five individual LED Christmas light bulbs, from a string of lights that did not have a "glob" in series with the bulbs. Each of the lights had a really tiny resistor in series with the bulbs. The stripes and body color on the resistors were so small I could not tell which was the body and which were the stripes. My cheap HF multimeter said the actual resistors were 260 ohms. I didn't try to clip lead the bulbs into a working string of lights so I wasn't able to measure the forward drop across the LED diode itself. I will try that later this week when I work on some more LED light strings. Right now my repair shop is working on filament light strings.
Wayne Chirnside <mark@faux.com>: Feb 21 09:40PM

On Sat, 20 Feb 2016 22:18:29 +0000, mroberds wrote:
 
 
> Standard disclaimers apply: I don't get money or other consideration
> from any companies mentioned.
 
> Matt Roberds
 
Best deal I've seen is batterysharks.com Brooklyn N.Y. Power Sonic.
I need to grab 5 next month and figure they're reputable enough to take a
chance.
soswow@gmail.com: Feb 21 01:32PM -0800

OK. I see what you mean. But I have problem understand how does PFC or any other logic board would be able to control LED.
The only connection power board has with main board via these 6 pin connection.
The only interesting bits here are ON/OFF and ADJ. Not sure if any of these would control output of the LEDs power output on other side of the power board:
Aleksandr Motsjonov <soswow@gmail.com>: Feb 21 01:34PM -0800

Can't find how to attach images here ... Replaying with email failed "Posting by email is not allowed, to post to this group visit https://groups.google.com/forum/#!forum/sci.electronics.repair"
Aleksandr Motsjonov <soswow@gmail.com>: Feb 21 01:35PM -0800

Here are two photos https://goo.gl/photos/CRivH9iwT6WRQQ5Q9
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