sci.electronics.repair@googlegroups.com

Google Groups

avagadro7@gmail.com: May 08 06:37AM -0700 with a mega Dell Vista at Canaveral Inlet, I was appawled watching roaches slither into the speaker grilles.   I was told the electronics are clear coated.   Roaches have to eat off course n leaving for the desert solved he problem.   Replacing fans found debris that does not interfere with operation via the clear coat. I guess there is a cost/insect proof curve here.   Insects are evolutionary durable. But eating is essential   Try gas. Fab or buy, a Pelican ?... leak roof box n find a not breathable not toxic gas. Afield, something like AC gas or ? just guessing.   Propane .... need to find if the gas dissolves plastic n clear coat.   Your nayborhood exterminator n electronics man will know.   leave the unit, take the covers off, in the box for 2 weeks.   then blow out the eggs with compressed air.   your basic problem was leaving the unit exposed to possible insect infiltration.   If you're in a buggy environment the laptops n equiPment go into containers n bags with insecticide.   oh yeah..... Home Depot has a gas emitter...the one I have is a sheet of white plastic housings that eliminated a common black under carpet bug from muh van.   when I pass by that area I'll look n post the brand.   PLACE UNIT IN LEAKPROOF CONTAINER ADD ALL INSECTICIDE HOUSINGS. SEAL. COME BACK 2 WEEKS.

tabbypurr@gmail.com: May 08 07:15AM -0700 > oh yeah..... Home Depot has a gas emitter...the one I have is a sheet of white plastic housings that eliminated a common black under carpet bug from muh van.   > when I pass by that area I'll look n post the brand.   > PLACE UNIT IN LEAKPROOF CONTAINER ADD ALL INSECTICIDE HOUSINGS. SEAL. COME BACK 2 WEEKS.   a tealight candle makes a pretty good oxygenless gas emitter.     NT

avagadro7@gmail.com: May 08 07:16AM -0700 > oh yeah..... Home Depot has a gas emitter...the one I have is a sheet of white plastic housings that eliminated a common black under carpet bug from muh van.   > when I pass by that area I'll look n post the brand.   > PLACE UNIT IN LEAKPROOF CONTAINER ADD ALL INSECTICIDE HOUSINGS. SEAL. COME BACK 2 WEEKS.   the 17501E has a step by step disassembly manual online from England.   Your unit may be online back 10 pages or pursued in Google Images.   buy the correct screwdriver size.

Jeff Liebermann <jeffl@cruzio.com>: May 07 10:27AM -0700 On Sun, 7 May 2017 10:19:45 -0000 (UTC), Cursitor Doom   >I was winding up one of my old HP spectrum analysers (my best one, as it >happens, been sitting around unused for years)   Model number? I couldn't tell from the photos.   My guess(tm) is the big electrolytic filter cazapitors are shorted, causing something between the line cord and the caps to smoke. Smoke usually means some resistive device burning up, although it can be a hot trace scorching the PCB. The color of the smoke would be helpful. Black is carbon comp or oil, white is plastic wire insulation, gray is phenolic, brown is epoxy or a dead mouse or insect infestation. There are smells associated with each one that is recognizable. I had a mouse take up residence inside an HP sweep generator last fall the demonstrated gray smoke and a horrible stench. If you can't find the source of the smoke or smell, shove one end of a 1/4" ID vinyl hose up your nose, and inhale while moving the other end of the hose all over the device. (Yes, I actually do this). It takes some practice and fortitude. For a mouse, have a vomit receptacle handy. You won't find any of this in books on electronic repair.   If you're dealing with very small amounts of smoke, that's either invisible, or pervasive (smoke everywhere), I suggest one of these airborne particulate detectors: <http://802.11junk.com/jeffl/Nikken%201394%20Air%20Quality%20Monitor/Nikken-AQM.jpg> <http://802.11junk.com/jeffl/Nikken%201394%20Air%20Quality%20Monitor/> My office was filled with smoke when I arrived one day and I had no idea where it was coming from. The Nikken "air quality" detector found it fairly quickly.   If you have money, consider buying an IR camera. By IR, I mean heat as in far-IR, not the common digital camera which does near-IR. Prices are coming down and you get something reasonable that plugs into an Android smartphone or iPhone. If you have a source of heat causing problems, that will find it. I borrow one from a friend occasionally. I've used one with great success isolating a bank of stepper motor controllers with conveniently exposed power transistors. It was easy to distinguish between warm normal, too hot, and stone cold.   -- 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

mike <ham789@netzero.net>: May 07 11:03AM -0700 On 5/7/2017 10:27 AM, Jeff Liebermann wrote: > I've used one with great success isolating a bank of stepper motor > controllers with conveniently exposed power transistors. It was easy > to distinguish between warm normal, too hot, and stone cold.   Thanks for the smoke info and the links. I bought a Nikken at a garage sale, but never had a manual for it.

mike <ham789@netzero.net>: May 07 11:59AM -0700 On 5/7/2017 10:27 AM, Jeff Liebermann wrote: snip > I've used one with great success isolating a bank of stepper motor > controllers with conveniently exposed power transistors. It was easy > to distinguish between warm normal, too hot, and stone cold.   The IR camera is one of those tools I rarely need, but it is REALLY helpful when I do. I bought the Flir for Android and took it back. Bought the SEEK and kept that one.   The Flir looks better because they combine the IR and regular cameras into one picture, but the actual IR resolution is less. The SEEK uses the camera in the smartphone and you have to swipe between visible and IR. Problem is that the IR and visible cameras are typically not along the same vertical or horizontal line and far apart. For close work, parallax is a killer. You can move the pictures relative to one another for a fixed location, but if you move, it can change a lot.   There are a couple of things to look out for: Smartphones must have USB OTG. For older phones, it's hard to tell whether it has OTG. There's an android app to tell if you have OTG, but I have phones that claim to be OTG, but don't work with the camera. I tried powering the camera externally without success. The microUSB sockets can face forward or backward. Obviously, IR selfies are not what you want. Ditto for side locations. At the time I looked, there was no way to rotate the image. I thought I could use it with the image rotated, but my brain couldn't handle it. I used one of the Best Buy $10 smart phones they had last year. Had the side connector. I built a clip into a phone protective case and mounted the camera as close as possible to the visible camera with the correct orientation. It worked, but the software didn't like my extension cable and locked up periodically. I also tried mounting the camera on a flexible extension so I could use it in an awkward location and still see the screen. Same cable problem. Some extension cables would not work at all. Others merely locked up a lot. That's not an IR problem, it's a USB problem. I yelled at customer support, but they were unsympathetic. They avoid the issue by claiming that only very few smartphones are supported. Maybe newer software fixes that...dunno.   If you get a SEEK from somewhere other than seek, you can't tell what you're getting. The original model was fixed focus, and worthless for close up work. You could buy a close up lens on ebay, but it was $55. Newer models have a variable focus lens that works very close up. Problem is that they did it without changing the model number. The only way to tell is to try it. There's a second model with variable focus, but narrower field of view for hunters. Looks exactly like the others.   One big problem with IR is the emissivity of the surface you're looking at. If you put a shiny metal pan on the stove, it looks cool to the IR sensor...just don't touch it, it's hot. Trying to determine the temperature of your shiny motorcycle head is a waste of time. That's a whole 'nother discussion topic...   Bottom line, if you have $200 to spend on a toy, the IR camera is a useful one. You'll be doing silly things like determining which of your dozen thermos bottles works best. Good times...

Jeff Liebermann <jeffl@cruzio.com>: May 07 12:29PM -0700 >Thanks for the smoke info and the links. >I bought a Nikken at a garage sale, but never had a manual for it.   <http://www.learnbydestroying.com/jeffl/Nikken%201394%20Air%20Quality%20Monitor/> The 3 PDF files at the bottom of the directory list are scans of the user manual. I do not have a service manual.   Some useful information from a previous thread: <http://www.edaboard.co.uk/air-pollution-particulate-sensor-package-t532756,start,15.html>   There are a bunch of new units for sale on eBay. <http://www.ebay.com/sch/i.html?_nkw=nikken+1394> -- 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

Cursitor Doom <curd@notformail.com>: May 07 08:27PM On Sun, 07 May 2017 10:27:51 -0700, Jeff Liebermann wrote:   > Model number? I couldn't tell from the photos.   8566B (this its display unit counterpart)   > the device. (Yes, I actually do this). It takes some practice and > fortitude. For a mouse, have a vomit receptacle handy. You won't find > any of this in books on electronic repair.   There was not really any visible smoke to speak of, Jeff. It was primarily the smell that indicated something had gone phut. Smelled like toasted PCB, but I can't see any burned areas at all. Might be a different story if I tore it right apart but so far as I can see, which is like 90% of it, nothing. One thing I can say is it's *definitely* not due to any infestation! Funny thing was, I couldn't detect the slightest smell at all after removing the covers; it was a very transient event with no noise either.   > invisible, or pervasive (smoke everywhere), I suggest one of these > airborne particulate detectors: > <http://802.11junk.com/jeffl/Nikken%201394%20Air%20Quality%20Monitor/ Nikken-AQM.jpg> > My office was filled with smoke when I arrived one day and I had no idea > where it was coming from. The Nikken "air quality" detector found it > fairly quickly.   I shall look into those links; many thanks.     > If you have money, consider buying an IR camera.   Yes, they're clearly very useful to have around. I'll see what's available here in the UK.

MJC <gravity@mjcoon.plus.com>: May 07 10:37PM +0100 In article <o5lugc1cok4vheiidopjthv12vrhck8p1g@4ax.com>, jeffl@cruzio.com says... > Black is carbon comp or oil, white is plastic wire insulation, gray is > phenolic, brown is epoxy or a dead mouse or insect infestation. There > are smells associated with each one that is recognizable.   Sounds very Catholic to this atheist! Maybe time to ask the pope?   Mike.

Jeff Liebermann <jeffl@cruzio.com>: May 07 03:21PM -0700 On Sun, 7 May 2017 22:37:43 +0100, MJC <gravity@mjcoon.plus.com> wrote:   >> are smells associated with each one that is recognizable.   >Sounds very Catholic to this atheist! Maybe time to ask the pope? >Mike.   I'm Jewish and asking the pope for advice would rather improper.   I've tried faith healing of various broken machines in the past. Sometimes, I get lucky, but mostly, it doesn't work. I get better results with burnt offerings and animal sacrifice.   The chemicals used to produce the traditional black and white smoke announcing the election of a new pope is a closely guarded secret. <www.nytimes.com/2013/03/12/world/europe/recipe-for-conclaves-black-and-white-smoke-remains-mystery.html> I'm fairly sure that a dead mouse is not one of the ingredients.   Please note that the colors I mentioned do not apply to continued and very hot combustion as in a structure fire, where the color of the smoke changes as the fire progresses: <http://www.fireengineering.com/articles/print/volume-158/issue-9/features/the-art-of-reading-smoke.html>   -- 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

John Robertson <spam@flippers.com>: May 07 11:26PM -0700 On 2017/05/07 5:31 AM, Cursitor Doom wrote:   > https://www.flickr.com/photos/128859641@N02/34376707301/in/dateposted- > public/   > But I can't see any sign of anything nearby having burned up. <shrug>   You were dialing the unit up in an effort to reform the electrolytic capacitors, and if you didn't know that before now you do (look up the term).   Electrolytic capacitors in the primary lower voltage power supply are the first suspects. I am not familiar with that unit, but there should be a section with B+ and possibly B- supplies - their filter caps are suspect. Also check if their bridge rectifiers were damaged, however that usually doesn't happen when a cap blows up.   Of course there are or should be fuses on the main power bus lines, check them and replace after finding the culprit.   John

mike <ham789@netzero.net>: May 08 12:08AM -0700 On 5/7/2017 11:26 PM, John Robertson wrote:   > Of course there are or should be fuses on the main power bus lines, > check them and replace after finding the culprit.   > John   The pictures suggest that the problem might be in the high voltage power supply. That's surely a switcher. Don't know if the main supply is a switcher. It's been suggested that you shouldn't try to reform caps by slowly ramping up the AC input voltages on swtichers. Disconnect the load side before you reform caps. Ditto for the switcher that is the HV supply. It probably doesn't like having it's input voltages all over the place.   Many circuits are designed to operate under specified conditions. Ramping up the AC is not a specified condition.   Depending on the competence of the engineer, she may have considered odd failure modes. But, if fixing it cost a penny, there would be resistance from the bean counters.   Point is that people will do stuff outside the spec, like ramping up the AC. You can have failure modes that you'd never think about if you considered only the specified worst-case conditions.   There may be no obvious cause for a failure caused by operator error trying to fix something that wasn't broke.

Cursitor Doom <curd@notformail.com>: May 08 09:37AM On Mon, 08 May 2017 00:08:14 -0700, mike wrote:   > having it's input voltages all over the place.   > Many circuits are designed to operate under specified conditions. > Ramping up the AC is not a specified condition.   You raise some very good and interesting points here which I shall bear in mind in future. So far as the sooty EHT components are concerned, it would seem that these can arise from a blown component elsewhere within the case; the smoke particles thereby emitted are attracted to the EHT cabling due to electrostatics. So quite possibly it's a red herring and there may be nothing amiss with the CRT supply circuitry at all. It may simply be evidence of a previously-fixed failure elsewhere.

tabbypurr@gmail.com: May 08 07:13AM -0700 On Monday, 8 May 2017 10:41:06 UTC+1, Cursitor Doom wrote: > electrostatics. So quite possibly it's a red herring and there may be > nothing amiss with the CRT supply circuitry at all. It may simply be > evidence of a previously-fixed failure elsewhere.   Are you unfamiliar with CRTs? It's normal for the EHT areas to be covered in a layer of electrostatically attracted dust & dirt.     NT

oldschool@tubes.com: May 08 03:48AM -0400 I have a friend who is an auto mechanic. He said that his shop recently bought a Thermal Gun, also called an Infared thermometer. He said it's quite handy, where it will detect coolant leaks, overheated parts of an engine, and even finds something like a hot connection in the wiring under a dashboard, and much more.   He is an expert with mechanics and has been in the business for over 30 years. He can repair auto wiring, but said he would not know the difference between a transistor or capacitor inside a car radio. Said he never learned electronics, just wiring.   Anyhow, I was telling him about my recent incident working on a preamp, and nearly burning my finger on an overheated IC chip. Almost immediately he asked me if I had a Thermal Gun. I had never even hear of them, but he explained how they work and said that it might be good for looking for hot components in an electronics device, in fact he said the manual said something about using it for that purpose.   RIght away I was thinking Big Money, but he said that they can be bought for as little as $35, but they bought one for around $120 because it had more features.   I asked how it works and he said you just point it at different parts of an engine or at a bundle of wires, or run it along an exhaust pipe to find leaks, and so on. And said there are ways to adjust its sensitivity, and it will locate clogged portions of a radiator and many more things.   This sounds like something that might be real handy for electronics work. Have any of you ever used them in this manner? If you have, are they worth the price to buy them for use on electronics?

Ralph Mowery <rmowery28146@earthlink.net>: May 08 10:00AM -0400 In article <j370hc5nbfnvqp1mu1teh4k550dg94lrm4@4ax.com>, oldschool@tubes.com says...   > This sounds like something that might be real handy for electronics > work. Have any of you ever used them in this manner? If you have, are > they worth the price to buy them for use on electronics?   I don't know how well they would work for electronic testing, but you can get them on ebay for about $ 10 and up. Most have laser pointers on them, but for close in work the laser does not point to exectally the heat source.   Search for infrared thermometer.

Mark Zacharias <mark_zacharias@sbcglobal.net>: May 08 06:38AM -0700 I retired last fall and this computer does not support my old Windoze Mail news reader. Can someone suggest a good free reader? I understand Free Agent is no longer "free".   For the moment I'm slumming it with Google Groups.   Mark Z.

Ralph Mowery <rmowery28146@earthlink.net>: May 08 09:53AM -0400 In article <d324d757-0c7e-4375-a022-6d24db4d6e8a@googlegroups.com>, mark_zacharias@sbcglobal.net says...   > I retired last fall and this computer does not support my old Windoze Mail news reader. Can someone suggest a good free reader? I understand Free Agent is no longer "free".   > For the moment I'm slumming it with Google Groups.   > Mark Z.   Not saying it is all that great,but I hae been using Microplanet Gravity after switching over to Win 10.   http://mpgravity.sourceforge.net/

"J.B. Wood" <arl_123234@hotmail.com>: May 08 09:59AM -0400 On 05/08/2017 09:38 AM, Mark Zacharias wrote: > I retired last fall and this computer does not support my old Windoze Mail news reader. Can someone suggest a good free reader? I understand Free Agent is no longer "free".   > For the moment I'm slumming it with Google Groups.   > Mark Z.   Hello. I use Mozilla Thunderbird both as an e-mail client and for usenet. Works fine for both IMHO. Sincerely,   -- J. B. Wood e-mail: arl_123234@hotmail.com

avagadro7@gmail.com: May 08 06:20AM -0700 CRC electronics cleaner from Walmart. Exotic cleaners from Allied Electronics   WD is deodorized kerosene.   WD would emulsify heavy deposits n then use CRC removing the WD.   CRC bottles on the shelf used with the pipe are compressed air/solvent tools.

avagadro7@gmail.com: May 08 06:41AM -0700 > WD is deodorized kerosene.   > WD would emulsify heavy deposits n then use CRC removing the WD.   > CRC bottles on the shelf used with the pipe are compressed air/solvent tools.   when cleaning with CRC n pipe, full flow is designed n appliedas the fluid evaps leaving a clean surface but with silicone or WD try an artists paint brush or Q tip .....PCBlaster also. PC asks for a slow down wobbly pin pressure for the first half tank.

"Ian Field" <gangprobing.alien1@virginmedia.com>: May 07 10:12PM +0100 <ohger1s@gmail.com> wrote in message news:3048fea5-5823-4512-ae41-3c16510cb9ab@googlegroups.com... > is why I saved a bunch of these when recycling the hosts.. These were > big, heavy, power pigs that drew a lot of current. I believe most of > filter assys were good for 20 amps.   Used to be every PC PSU - but been a while since I've seen one there.

w9gb <gregory.beat@gmail.com>: May 07 02:40PM -0700 Gunther: "HP Audio Oscillator" ????   PLEASE Be Specific, model number ? ==== HP and Office machine mfg. used a proprietary 3-pin Oval connector in 1950s and 1960s. The HP Audio Oscillators "bridged" this period --- so the connector changed -- deoendung on mfg. date. The Oval connector is sometimes identifued as AC-3G, and the plug as PH-163 There are TWO cable sets: Volex (Belden) P/N: 17280 10 B1 ; Belden P/N: 17952 (Reverse polarity, Line/Neutral swap) --- STANDARDS : Beginning in 1970, the International Electrotechnical Commission (IEC) released IEC 320 https://en.m.wikipedia.org/wiki/International_Electrotechnical_Commission as its first attempt to Globally standardize Appliance Power Connectors (on appliance)   A separate effort has been working to standardize the commercial AC power voltages and its power pkugs/sockets. https://en.m.wikipedia.org/wiki/AC_power_plugs_and_sockets   IEC 60320 Appliance couplers for household and similar general purposes (Today's standard). https://en.m.wikipedia.org/wiki/IEC_60320 Reference Chart http://www.stayonline.com/reference-iec320.aspx   greg

Jeff Liebermann <jeffl@cruzio.com>: May 07 10:07AM -0700 >Most of Congress probably believes >Daylight Saving adds daylight! Remmber: >they don't read what they pass.   Maybe, but most voters also don't read the various initiatives and referendums on which they vote. Worse, few voters could recite the names of their local government representatives, as well as whom and what they represent and advocate. It's the blind leading the blind.   So, why does representative government still work? Because elected representatives have staff to read through the various measures and deal with the constituency. Afterwards, they provide a very simplified summary for the representative to read and digest.   >consumption, but lazy people like it >because it delays sunrise and they can >stay up later and sleep in.   There have been various research projects, few of which seem to be objective and unbiased. One of the more comical that I read was a survey of families paid to change their clocks according to the old DST system, and then comparing energy consumption only in the approximately two months that were involved in the change. If I find a link, I'll post it. The results were almost random, but that was apparently fixed by carefully cherry picking the data from those who most closely followed the test guidelines. Some tests and surveys: <https://en.wikipedia.org/wiki/Daylight_saving_time#Energy_use> I think this might be it: "The United States Department of Energy (DOE) concluded in a 2008 report that the 2007 United States extension of DST saved 0.5% of electricity usage during the extended period. [90] This report analyzed only the extension, not the full eight months of DST, and did not examine the use of heating fuels."   Perhaps we can escape the horrors of DST by getting away from the rigid 8 hr work day, and replacing it with a 6 hr winter work day, and a 12 hr summer work day, when there are more hours of sunlight.     -- 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

thekmanrocks@gmail.com: May 07 12:35PM -0700 Jeff Liebermann wrote: " "The United States Department of Energy (DOE) concluded in a 2008 report that the 2007 United States extension of DST saved 0.5""   The DOE can publish any conclusions that the utilties find favor with.   "Perhaps we can escape the horrors of DST by getting away from the rigid 8 hr work day, and replacing it with a 6 hr winter work day, and a 12 hr summer work day, when there are more hours of sunlight. "     Perhaps we can escape the horrors of DST by shifting business hours earlier in the day. '9 to 5' makes a nice song on the radio, but it wastes a lot of early morning daylight. I personally would quickly embrace an 8-4 first shift, so the workday is rarely ever impinged upon by darkness.   Getting folks to go to bed before midnight is another challenge, however.

You received this digest because you're subscribed to updates for this group. You can change your settings on the group membership page. To unsubscribe from this group and stop receiving emails from it send an email to sci.electronics.repair+unsubscribe@googlegroups.com.