- Deoxt - 7 Updates
- Debug advice Kenmore coldspot 106-59422801 stopped refrigerating - 17 Updates
- OT A drone-mounted chainsaw, what could possibly go wrong? - 1 Update
| Ralph Mowery <rmowery28146@earthlink.net>: Jul 11 03:19PM -0400 I have not used it but just bought a spray can of Deoxit. From reading about it, it seems to be the greatest stuff for cleaning contacts. I have an old Tectronix Scope 465B that one chanel has a flakey input switch. The manual says only to use isopropal alcohol to clean it with, I did that with some 99% and it helped some, but thinking of using some of the Deoxit on the switch. Would that be ok or not. I would hate to mess up the switches as they would be almost impossiable to find replacements for . |
| dplatt@coop.radagast.org (Dave Platt): Jul 11 01:51PM -0700 >using some of the Deoxit on the switch. Would that be ok or not. >I would hate to mess up the switches as they would be almost impossiable >to find replacements for . First recommendation would be "stick to the manufacturer's rules". They may know something we don't. I've read a number of comments (Hi, Jeff!) that DeOxIt is *not* a good thing to use on gold-plated contacts. Gold plating is often somewhat porous, and the DeOxIt can creep through the pores down to the base metal and may actually attack it. This can cause the gold plating to fail. CAIG makes a different product ("ProGold") which is intended for gold-plated contacts, and if I understand correctly, it's intended to avoid this problem. Your Tek's switch may actually be suffering from contact wear, rather than contact surface contamination. If I recall properly, the delicate contact fingers in the switch do "rub" slightly on the contact pads when the switch is activated, and over time this can wear away the gold plating, and the contact don't work well after that. Cleaning (with ispropanol or anything else) isn't going to help this situation more than very temporarily. I haven't found a solution (so to speak :-) ) for this sort of problem, other than an actual repair of the switch (replace the contact fingers) and as you note, this may not be possible due to lack of available parts. |
| jurb6006@gmail.com: Jul 11 01:58PM -0700 When in doubt, put some Deoxit on a Qtip and rub the plastic body of the switch. Check it for any softening. Try to scratch it with a dental pick. Then try to scratch an untouched one. The danger is not to the contacts. I have seen acetone and Qdope thinner (which is toluene) do some very nasty things to plastic. If Deoxit has either in it you might be much better off sticking with the alcohol. Plus, Deoxit uses a chemical known as a reducer which actually uncorrodes the metal - thus the name. I really do ot know about the properties of that stuff. |
| Ralph Mowery <rmowery28146@earthlink.net>: Jul 11 08:25PM -0400 In article <4fdd5d-fvu.ln1@coop.radagast.org>, dplatt@coop.radagast.org says... > problem, other than an actual repair of the switch (replace the > contact fingers) and as you note, this may not be possible due to lack > of available parts. Usually it is best to stay with what the manufacturer recommends, but in this case the Deoxit was probably thought of years after the scope was made. Thanks for the advice of the Deoxit Gold. Maybe I will try that at some point instead of the kind I have. As stated above I have been repairing some electronics over the last 40 years as a hobby and never tried the Deoxit. As all reports seem to say this stuff cures anything that WD 40 won't.. ( I never use WD 40 by the way for various reasons.) It has been a while from the last time I looked in the scope, but best I remember that while the part you turn is a rotary switch, the contacts are actually slide switches of sorts. Then as it was mentioned it may attack the plastic. Some cleaners do and some don't. I used to use LPS cleaner and never found plastic that it would affect. |
| Jeff Liebermann <jeffl@cruzio.com>: Jul 11 05:29PM -0700 On Mon, 11 Jul 2016 13:51:16 -0700, dplatt@coop.radagast.org (Dave Platt) wrote: >I've read a number of comments (Hi, Jeff!) that DeOxIt is *not* a good >thing to use on gold-plated contacts. That wasn't me. The problem is that Caig has juggled the formulation for Deoxit and/or Cramolin has changed over the years. My main problem with the old stuff was that it uses oleic acid. Nothing wrong with that since it's the acid that removes the oxides from the contacts. The problem is that it will also attack copper if left on the contacts for too long. I also found that I can make things worse by mixing my own and using too much oleic acid. It will not attack gold or silver plated contacts, so those are safe. So, if you're using the old stuff with oleic acid, wash off the contacts with alcohol after you've removed the black silver oxide coating. Gold does not oxidize so using an oxide remover on gold contacts is a total waste of time. At worst, gold contacts will have a layer of tar produced by the last attempt to lubricate the contacts. The rest of the formulation is some form of naphtha. Lots of things contain various forms and mixes of naphtha. Usually, lighter fluid is mentioned, but that might be to volatile. I use Coleman camp fuel, which works well enough. Or, just buy the pure stuff: <https://www.google.com/#q=naphtha&tbm=shop> They all work. Now, for the switches... Think about what you're trying to accomplish. You're trying to remove a layer of some kind of oxide from the contacts. You're also trying to remove any tar left over from the previous attempt to lube the contacts. Any mild acid and organic solvent will do that. You don't need anything super strong. If you want something with some lubricant added, use contact cleaner, or maybe mix in your favorite oil. Just make sure it doesn't turn into a sticky tar when it evaporates. Summary: - If it's gold contacts, use alcohol because there's no oxides. - If it's silver contacts, use contact cleaner, Deoxit, Cramolin, or whatever removes the black silver oxide from the contacts. Then wash it off with alcohol and leave it alone. - I'm not a big fan of grease and oil as a contact lubricant. -- 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 |
| Phil Allison <pallison49@gmail.com>: Jul 11 07:35PM -0700 Ralph Mowery wrote: > years as a hobby and never tried the Deoxit. As all reports seem to say > this stuff cures anything that WD 40 won't.. ( I never use WD 40 by the > way for various reasons.) ** IME, good old WD40 cures many contact problems that DeOxit will not - particularly when penetration deep into a mechanism is required. There are many similar products too, like CRC2-26 that have the same formulation and so do exactly the same job while costing more. What the heck do you use ? .... Phil |
| Phil Allison <pallison49@gmail.com>: Jul 11 07:48PM -0700 Jeff Liebermann wrote: > gold or silver plated contacts, so those are safe. So, if you're > using the old stuff with oleic acid, wash off the contacts with > alcohol after you've removed the black silver oxide coating. ** The dark coating that forms on silver is *silver sulphate* (aka Ag2S). Luckily it is quite soft and wears off switch contacts in normal use so a build up may occur which can be flushed clean with products like WD40. The idea of using oleic acid on electrical contacts worries as it must become conductive under enough voltage. .... Phil |
| "Danny D." <dannydiamico@yahoo.com>: Jul 11 10:06PM On Mon, 11 Jul 2016 11:11:31 -0400, Bob Engelhardt wrote: > WE "got's to know": did you try it & what happened? I apologize for missing yesterday. I had a family engagement. All the salmon is gone by now, so I have more time anyway. :) What do you make of these results? Given: 1. Relay continuity http://i.cubeupload.com/EpNXUi.jpg 2. Relay power: http://i.cubeupload.com/AIlj4p.jpg 3. I guess that these are the motor terminals: http://i.cubeupload.com/23ew1U.jpg 4. Here is the suggested test jig with the cap in series with the terminal that I "think" is the START terminal: http://i.cubeupload.com/WrCzv4.jpg 5. I accidentally hooked it up backward the first time, with the HOT wire splitting into two, one of which went through the capacitor and then to what I think is the compressor START terminal - and the other hot went to what I think is the compressor RUN terminal. http://i.cubeupload.com/UJcLZD.jpg 6. Then I labeled the wires, and hooked it up the opposite way - with the HOT wire going only to what I think is the compressor topward COMMON terminal. One neutral wire went to the capacitor and then to what I think is the compressor bottom-forward-facing START terminal and the other neutral went to what I think is the compressor bottom-rearward facing RUN terminal. http://i.cubeupload.com/ryMq7y.jpg In both tests, the motor just hummed but did not appear to start. When I pulled what I think is the start wire neutral off, the hum didn't change. What do you make of this? What are my options? (PS: Money is tight). |
| "Danny D." <dannydiamico@yahoo.com>: Jul 11 10:13PM On Mon, 11 Jul 2016 15:02:16 -0700 (PDT), Uncle Monster wrote: > A 12uf 5,000 volt capacitor charged up could hurt you. ^_^ The markings on this cap are: http://i.cubeupload.com/QBVskg.jpg 1. 12uF 2. 180VAC (it was charged to 120VAC) 3. 10,000AFC (I presume this is cycles?) 4. 50/60Hz Can that 120VAC 12uF zap kill me? Is it safe (to the cap) to short the terminals? |
| "Danny D." <dannydiamico@yahoo.com>: Jul 11 11:19PM On Fri, 8 Jul 2016 23:22:01 -0000 (UTC), Danny D. wrote: Here is a summary, from top to bottom of where it's at. SUMMARY: I don't know if I tested it correctly, nor if I identified the circuit correctly, but if I both identified and tested the circuit correctly, then the compressor motor is bad. However, maybe I made a mistake? DETAILS: 0. Bought in 2010, the wife's Sears Kenmore coldspot 106-59422801 refrigerator/freezer just stopped working at the same time that a periodic "humming and then clicking" noise started happening. 1. Here is the parts diagram (I annotated in red with the names of the parts): http://i.cubeupload.com/5z2J05.gif 2. Condenser fan is blowing full time (dunno if it always did that). http://i.cubeupload.com/dQOTKL.jpg 3. Condenser coils are at room temperature and are dusty: http://i.cubeupload.com/jgkVXv.jpg 4. Compressor tries to start every few minutes, and hums for about 15 seconds and then the overload relay clicks off. http://i.cubeupload.com/p2OiCZ.jpg 5. Top of compressor is hot to the touch so I let it cool down overnight but no change in operation: http://i.cubeupload.com/wAX37P.jpg 6. Here is a video of the humming noise kick on every five minutes for about 10 or 20 seconds and then a click when it shuts off: http://tinypic.com/r/e6abk7/9 Here is another video of the humming noise and click off the next day when the compressor was cold: http://tinypic.com/r/20ubk3d/9 7. I removed the 12uF capacitor which looked good and had it tested at an appliance parts counter and it tested good. http://i.cubeupload.com/PiHwXk.jpg 8. I removed the overload and start relay (combination kit): http://i.cubeupload.com/uHWsBd.jpg http://i.cubeupload.com/EnZxki.jpg 9. I ran a few continuity tests, which seemed to return what may be "normal" results: http://i.cubeupload.com/PmCLK7.jpg 10. Unpowered, I shorted the two capacitor terminals in the relay so that I could test continuity: http://i.cubeupload.com/3tJTV7.jpg 11. The relay has only two wires going into it, and three holes coming out. http://i.cubeupload.com/HBepTj.jpg 12. Disconnected from power, and with the capacitor terminals shorted: a. Red power input terminal went directly to the relay top output pin b. White neutral input terminal went directly to *both* lower output pins http://i.cubeupload.com/I3t2HZ.jpg 13. If I remove the short between the capacitor pins, it changes to: a. Red power input still went directly to the relay top output pin b. White neutral input still went directly to the rearward lower output pin c. White neutral input no longer innervates the forward lower output pin http://i.cubeupload.com/JwcELQ.jpg ====================== 14. In summary, this is the relay continuity http://i.cubeupload.com/EpNXUi.jpg (Note that this is not the type of relay that you can shake to hear rattling inside.) 15. Powered, the relay has two neutrals and one hot (I would have thought it should be the other way around, but I tested the neutrals to the chassis of the frig): http://i.cubeupload.com/AIlj4p.jpg 16. Give those two results above, I am *guessing* that these are the motor terminals (top seems to be COMMON (hot), Forward-bottom seems to be START (neutral), and rearward bottom seems to be RUN (neutral): http://i.cubeupload.com/23ew1U.jpg (Again, I would have thought it would be a common neutral and not a common hot but it doesn't seem to be wired that way.) 15. Here is a slightly better test jig with the 12uF/180VAC start capacitor in series with the terminal that I "think" is the START terminal: http://i.cubeupload.com/WrCzv4.jpg 16. I accidentally hooked it up backward the first time, with the HOT wire splitting into two, one of which went through the capacitor and then to what I think is the compressor START terminal - and the other hot went to what I think is the compressor RUN terminal. http://i.cubeupload.com/UJcLZD.jpg 17. Then I labeled the wires, and hooked it up the opposite way - with the HOT wire going only to what I think is the compressor topward COMMON terminal. One neutral wire went to the capacitor and then to what I think is the compressor bottom-forward-facing START terminal and the other neutral went to what I think is the compressor bottom-rearward facing RUN terminal. http://i.cubeupload.com/ryMq7y.jpg In both tests, the motor just hummed but did not appear to start. When I pulled what I think is the start wire neutral off, the hum didn't change. What do you make of these results? |
| Bob Engelhardt <BobEngelhardt@comcast.net>: Jul 11 07:43PM -0400 On 7/11/2016 6:06 PM, Danny D. wrote: ... > 4. Here is the suggested test jig with the cap in series with the terminal > that I "think" is the START terminal: > http://i.cubeupload.com/WrCzv4.jpg Yep, that's right. > what I think is the compressor START terminal - and the other hot went to > what I think is the compressor RUN terminal. > http://i.cubeupload.com/UJcLZD.jpg Actually, with AC, it's all the same. Functionally, that is - there is a safety difference. > When I pulled what I think is the start wire neutral off, the hum didn't > change. > What do you make of this? You've already determined that there is continuity on the start winding, so no difference when pulling it does not indicate an open winding. The no-difference is due to the cap-in-series which limits the start current to about 1/2 amp (its impedance is 220 ohms), while the run current is likely 6, 8, or more amps. I.e., the start current is too small to notice when it's removed. > What are my options? > (PS: Money is tight). I can't think of anything else to try. It seems pretty conclusive that the compressor is shot. Oh ... somebody said that the "Freon" line could be plugged. That could be, but diagnosing and fixing that would be just as expensive. I suppose, for the hell of it, you could try reversing the start & run leads. Can't hurt & maybe there was a brain fart that got their identities reversed. Bob |
| "tom" <tmiller11147@verizon.net>: Jul 11 07:49PM -0400 "Danny D." <dannydiamico@yahoo.com> wrote in message news:nlruv7$c7f$1@news.mixmin.net... > 5. Yank off the start wire as soon as the compressor starts > If the compressor starts, then it's good. > If not ... Oh, oh, oh... Set up a video and put this on youtube. It might be a winner. |
| Bob Engelhardt <BobEngelhardt@comcast.net>: Jul 11 07:49PM -0400 On 7/11/2016 7:19 PM, Danny D. wrote: > On Fri, 8 Jul 2016 23:22:01 -0000 (UTC), Danny D. wrote: > Here is a summary, from top to bottom of where it's at. > ... Nicely done. |
| "tom" <tmiller11147@verizon.net>: Jul 11 08:06PM -0400 "Danny D." <dannydiamico@yahoo.com> wrote in message news:nm19hs$51n$1@news.mixmin.net... > When I pulled what I think is the start wire neutral off, the hum didn't > change. > What do you make of these results? Just for the hell of it can you take an ohmmeter measurement from any of the three terminals to the case? It should show open (very high resistance). If it measures any resistance, the compressor is bad. |
| "Danny D." <dannydiamico@yahoo.com>: Jul 12 12:08AM On Mon, 11 Jul 2016 19:43:35 -0400, Bob Engelhardt wrote: > Actually, with AC, it's all the same. Functionally, that is - there is > a safety difference. I hadn't thought of that. I did avoid touching the chassis. :) > current to about 1/2 amp (its impedance is 220 ohms), while the run > current is likely 6, 8, or more amps. I.e., the start current is too > small to notice when it's removed. Thanks for explaining that the start current is much less than the run current, so the motor "sounds" wouldn't be easily discerned. > the compressor is shot. Oh ... somebody said that the "Freon" line > could be plugged. That could be, but diagnosing and fixing that would > be just as expensive. I don't know how to test for a plugged freon line either. :( > I suppose, for the hell of it, you could try reversing the start & run > leads. Can't hurt & maybe there was a brain fart that got their > identities reversed. Thanks for that idea. I just reversed the START and RUN terminals, and there was no difference. It hummed but didn't kick on. One problem is that I can't tell what's going on from the sound, but when I hooked all the old parts back, it kicked off again as it did when I started this thread. Sigh. |
| "Danny D." <dannydiamico@yahoo.com>: Jul 12 12:09AM On Mon, 11 Jul 2016 16:28:36 -0700 (PDT), Uncle Monster wrote: > I doubt the capacitor would cause your demise unless you jabbed electrodes into your heart and discharged the cap through them. The safest way to discharge any motor start/run capacitor is by putting a five thousand ohm resistor across it. I've used a 60 watt light bulb across the terminals of a big motor start electrolytic capacitor because shorting it with a screwdriver or piece of wire can damage the Faston terminals. If you're worried about any charge on the capacitor, use my light bulb trick. ^_^ Ah, resistance. Why didn't I think of that. I'll make a test jig out of the existing wires, and put a 5K ohm resistor on it. Thanks for that idea. |
| "Danny D." <dannydiamico@yahoo.com>: Jul 12 12:23AM On Tue, 12 Jul 2016 00:08:49 -0000 (UTC), Danny D. wrote: > One problem is that I can't tell what's going on from the sound, but when I > hooked all the old parts back, it kicked off again as it did when I started > this thread. The main problem I have is that I don't know what a good compressor humming sounds like, compared to a bad compressor humming. Is it safe to leave the test jig in place for an hour or three to see if the lines get cold? |
| "Danny D." <dannydiamico@yahoo.com>: Jul 12 12:24AM On Mon, 11 Jul 2016 19:49:56 -0400, tom wrote: > Oh, oh, oh... Set up a video and put this on youtube. It might be a winner. Heh heh... You should have heard the wife scream when "I" got zapped by the 12uF capacitor! |
| "Danny D." <dannydiamico@yahoo.com>: Jul 12 12:28AM On Mon, 11 Jul 2016 20:06:03 -0400, tom wrote: > Just for the hell of it can you take an ohmmeter measurement from any of the > three terminals to the case? It should show open (very high resistance). If > it measures any resistance, the compressor is bad. Thanks for that advice, as I'm at a loss as to how to know the humming sounds of a good versus bad compressor. I did check the resistance when I was trying to figure the pinout of the compressor three pins, and all are insulated. But thank you for that idea as I had not mentioned that test. |
| "tom" <tmiller11147@verizon.net>: Jul 11 08:33PM -0400 "Danny D." <dannydiamico@yahoo.com> wrote in message news:nm1d9e$bgh$1@news.mixmin.net... > sounds like, compared to a bad compressor humming. > Is it safe to leave the test jig in place for an hour or three to see if > the lines get cold? If the compressor is running, the discharge line (the smaller copper tube) will get warm (hot). |
| Bob Engelhardt <BobEngelhardt@comcast.net>: Jul 11 08:35PM -0400 On 7/11/2016 8:23 PM, Danny D. wrote: >> this thread. > The main problem I have is that I don't know what a good compressor humming > sounds like, compared to a bad compressor humming. That's a good point! Maybe it IS running with test jig. Do you have an AC ammeter? If so, check if the run current drops after a second or two with the test jig. If so, it's running. But if it stays high, it's not. > Is it safe to leave the test jig in place for an hour or three to see if > the lines get cold? If it isn't running, the excess current from it being in the start mode continuously will overheat the compressor. That's what the overload device was protecting against. You might be thinking "So what?" & I see that point, but I'm not going to say that it would be safe. Bob |
| "Danny D." <dannydiamico@yahoo.com>: Jul 12 02:13AM On Mon, 11 Jul 2016 20:33:08 -0400, tom wrote: > If the compressor is running, the discharge line (the smaller copper tube) > will get warm (hot). Which line in this picture is that "discharge line" that will get hot? http://i.cubeupload.com/wAX37P.jpg How long will it take to get hot? |
| "Danny D." <dannydiamico@yahoo.com>: Jul 12 02:18AM On Mon, 11 Jul 2016 20:35:30 -0400, Bob Engelhardt wrote: > That's a good point! Maybe it IS running with test jig. Do you have an > AC ammeter? If so, check if the run current drops after a second or two > with the test jig. If so, it's running. But if it stays high, it's not. I have a 10Amp Fluke 77 but I lent it to an ex brother in law, and it has never returned. So, currently I'm stuck with a radio shack dial ammeter, but it does have an inductive clip that I can clip on. Looking at the manual it has 3A, 15A, and 30A AC current ranges. > continuously will overheat the compressor. That's what the overload > device was protecting against. You might be thinking "So what?" & I see > that point, but I'm not going to say that it would be safe. I don't want to burn down the house for a frig! |
| Ryou Kudo <RyouKanataKudo@nttdocomo.co.jp>: Jul 12 02:20AM On Mon, 11 Jul 2016 20:35:30 -0400, Bob Engelhardt wrote: > If it isn't running, the excess current from it being in the start mode > continuously will overheat the compressor. Actually, I just realized I could leave the START wire off, right? So the question is whether it's dangerous or not to just run with the two wires connected to the compressor for a few hours, RUN and COMMON? |
| Jeff Liebermann <jeffl@cruzio.com>: Jul 11 05:37PM -0700 On Mon, 11 Jul 2016 10:39:14 -0400, "(PeteCresswell)" <x@y.Invalid> wrote: >>Strange how someone with enough knowledge to modify/construct and balance a drone large enough to lift a chain saw wouldn't understand this. >My impression was that their goal was to make an entertaining video and >not an actually-functional tree-trimming device. Sigh. Breaking off icicles and decapitating snow men is easy. The motor doesn't even need to be running. Simple inertial will do the job. However, if one tried to cut a limb or trunk with the saw, with nothing holding onto the saw, it will immediately be launched in the direction of the tree. It could be done by jamming the log between the chain and the felling dog (spikes), but maneuvering the octocopter to provide the rotating motion necessary to complete the cut is in my never humble opinion extremely difficult. If you disagree, try suspending a chain saw from a collection of strings, as with a puppet, and try it yourself. The experience should be similar to the octocopter at much lower cost. Incidentally, I looked up the load capacity of a similar octocopter and found that it will lift 50 lbs, which is well above the weight of a similar small chain saw. -- 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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