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DaveC <not@home.cow>: Jul 04 07:16PM -0700 A new cable works wonderfully. For maybe 6 weeks. Then when I use the Samsung phone while charging... "Beep-boop, beep-boop", charge indicator on, off, on, off. Over and over.   Replace cable, all is well.   Rinse, repeat.   Buying a new cable every month is not expensive but also not something one should have to do.   Yes, I've cleaned out the phone's connector of lint and debris.   I've seen instructions re. fixing the cable connector by bending the tension pins (external, bottom-side) but there are several types of tensioning designs; not all are repairable, IME.   Anyone find a long-term fix, or quality cable that avoids this problem altogether?   Thanks.

John Larkin <jjlarkin@highlandtechnology.com>: Jul 04 07:41PM -0700 >Anyone find a long-term fix, or quality cable that avoids this problem >altogether?   >Thanks.   Maybe the phone connector is damaged. It gets a lot of wear. My phone has some damaged pins that mangled the mates too. It has cradle-charging connections on the side, so I use that now.   USB is really mediocre. The polarization is always ambiguous (except for the ancient B connector), the pins are flimsy, and there are so many different "universal" connectors.     --   John Larkin Highland Technology, Inc picosecond timing precision measurement   jlarkin att highlandtechnology dott com http://www.highlandtechnology.com

Jeff Liebermann <jeffl@cruzio.com>: Jul 04 08:20PM -0700 >A new cable works wonderfully. For maybe 6 weeks. Then when I use the Samsung >phone while charging... "Beep-boop, beep-boop", charge indicator on, off, >on, off. Over and over.   It's designed to destroy the cable instead of the connector in your unspecified model Samsung phone. In previous mini-USB connector was a problem because it would destroy the connector in the phone which would be far more expensive than replacing the USB cable. The improved micro-USB connector destroys the much cheaper USB cable. I think I pay about $1/ea for cables. <http://www.ebay.com/itm/141558130661> You might want to stock up on cables.   These might explain the situation: <http://electronics.stackexchange.com/questions/18552/why-was-mini-usb-deprecated-in-favor-of-micro-usb> <https://en.wikipedia.org/wiki/USB#Durability>   I can't tell from your description why your cables are failing. I don't think it's the cables as most of them are quite durable. The connector is rated for 10,000 insertion/removal cycles. If you plugged and unplugged your phone 4 times per day, that's 2,500 days or 6.8 years.   I occasionally see some problems caused by rubberized phone "protectors". The charging connector doesn't quite fit through the rubber case so the user applies brute force to complete the connection. Sometimes the hole in the case is misaligned with the phone connector or sometimes the molded plug on the cable is too large to fit neatly in the hole in the case. If you suspect the case, you might try a different one, with a larger opening for the charger connector.   Another problem is arcing. The micro-USB connector system is made to be hot pluggable/unpluggable. Unfortunately, some phones and chargers have large capacitors across the output which can pit the gold plated contacts. The chargers are suppose to start at a low current, negotiate the maximum current, and then switch to the higher (2A) charging current. Some cheap chargers go directly to 2A causing the arcing. Some dirt and crud in the connector can produce a tiny arc. The problem is that you have to tear the plug apart to see the damage to the contacts. You might try that on one of your numerous failed cables. If that seems to be the problem, which I think quite likely, buy a different and better charger.   <http://www.righto.com/2012/03/inside-cheap-phone-charger-and-why-you.html> <http://www.righto.com/2012/10/a-dozen-usb-chargers-in-lab-apple-is.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

DecadentLinuxUserNumeroUno <DLU1@DecadentLinuxUser.org>: Jul 05 03:37AM -0400 >Buying a new cable every month is not expensive but also not something one >should have to do.   The trick is to insert the cable in the phone first, no power, THEN insert the power supply/charger end.

mike <ham789@netzero.net>: Jul 05 03:56AM -0700 On 7/4/2016 8:20 PM, Jeff Liebermann wrote: > connector is rated for 10,000 insertion/removal cycles. If you > plugged and unplugged your phone 4 times per day, that's 2,500 days or > 6.8 years.   Would be interesting to learn how they estimated that reliability. If you have a machine that properly aligns the connectors when plugged, maybe. When a human plugs it in, rips it out, uses the device while charging so that the connector gets pulled, pushed, twisted, things can get loose really fast.   I buy most of my devices used at garage sales. I've never had any problems with mini-usb connections. Virtually ALL acquired devices with micro-usb connectors are loose or intermittent. I've switched to add-on Qi charge adapters that stay connected permanently and don't get stressed in use.

DaveC <not@home.cow>: Jul 05 07:07AM -0700 On 5 Jul 2016, DecadentLinuxUserNumeroUno wrote:   > The trick is to insert the cable in the phone first, no power, THEN > insert the power supply/charger end.   How does this make it not loose over time?

DaveC <not@home.cow>: Jul 05 07:09AM -0700 On 4 Jul 2016, John Larkin wrote:   > Maybe the phone connector is damaged. It gets a lot of wear. My phone > has some damaged pins that mangled the mates too. It has > cradle-charging connections on the side, so I use that now.   I think the fact that for 6 weeks there's no problem eliminates the possibility that the phone connector is damaged.   It's not the electrical pins, it's the robustness of the physical retention mechanism.   Thanks, Dave

DaveC <not@home.cow>: Jul 05 07:18AM -0700 > think I pay about $1/ea for cables. > <http://www.ebay.com/itm/141558130661> > You might want to stock up on cables.   All the purdee colors! This is the brand you buy? (looking for a recommendation not just Google results...)   > connector is rated for 10,000 insertion/removal cycles. If you > plugged and unplugged your phone 4 times per day, that's 2,500 days or > 6.8 years.   Hence my inquiry here.   How often do *you* replace a micro-USB cable, Jeff? > I occasionally see some problems caused by rubberized phone "protectors".   Not using a case or protector. Thanks.

Jeff Liebermann <jeffl@cruzio.com>: Jul 05 07:42AM -0700 >> plugged and unplugged your phone 4 times per day, that's 2,500 days or >> 6.8 years.   >Would be interesting to learn how they estimated that reliability.   Durability or reliability? This is old but probably good enough: <http://www.usb.org/developers/docs/devclass_docs/CabConn20.pdf> See Pg 14 under "durability". It references EIA-364-09 for the number of insertion/extraction cycles. 1500 cycles 5000 cycles for Mini B 10,000 cycles for Micro series 10,000 cycles for ruggedized Standard A Cycle rate of 500 cycles per hour if done automatically and 200 if manual cycle. EIA-364-09 does not specify a specific test fixture (section 2): <http://www.kekaoxing.com/upimg/standard/EIA/EIA-364-09C.pdf> I've seen one in action at a local headset manufacturer. It was rather boring to watch. Something like this: <http://qctest.sale.fustat.com/pz69bafb9-rotating-eccentric-type-usb-connector-durability-testing-machine-durability-test-equipment.html> but made in house. More: <http://gizmodo.com/the-r-d-machines-that-push-your-smartphone-til-it-break-1684892168> My guess(tm) is that it could be done properly with just a rotating crank and piston arrangement instrumented with strain and force gauges.   >When a human plugs it in, rips it out, uses the device while charging >so that the connector gets pulled, pushed, twisted, things can get loose >really fast.   Such tests are usually performed under ideal and controlled conditions. Unless connector side loading and torque limits are specified, it's unlikely that anyone tests for those. Presumably, the metal framework around the micro-USB connector will survive longer than the mating contacts so direct insertion/extraction testing should provide an adequate test. However, if you want to test for surviving various forms of abuse, it will need to be added to the specification.   >problems with mini-usb connections. >Virtually ALL acquired devices with micro-usb connectors are loose or >intermittent.   Again, that's intentional. If they were a snug fit, abrasive action would wear down the connector rather rapidly. There was also some effort to minimize (not maximize) the retention forces so that it would disconnect during cord pulling, dropping, and use as a yo-yo.   >I've switched to add-on Qi charge adapters that stay connected permanently >and don't get stressed in use.   That's probably the way to go. However, that only solves the charging problem. There's still all the other stuff that the USB connector is used for (USB OTG, file transfers, external devices, etc). USB connectors are unlikely to disappear.   -- 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

DaveC <not@home.cow>: Jul 05 07:59AM -0700 On 4 Jul 2016, Jeff Liebermann wrote:   > I think I pay about $1/ea for cables. > <http://www.ebay.com/itm/141558130661>   The offer at that link is confusing: it first says "Price: US $0.99" and I presume quantity is 1.   Then when you go to the drop-down menus for quantity, you have the choice of "X1" and "X2" which changes the price to $3.00 and $5.19 respectively.   Huh?   Anyone know what's going on there?

Jeff Liebermann <jeffl@cruzio.com>: Jul 05 08:07AM -0700 >> You might want to stock up on cables.   >All the purdee colors! This is the brand you buy? (looking for a >recommendation not just Google results...)   Actually yes, I do buy colored USB cables. They help keep my charging mess somewhat organized so that I plug the stuff that needs 0.5A into the tiny chargers, and the stuff that needs 2A into the larger chargers.   I don't have any recommended brand or supplier. I pass out USB cables and chargers at my palatial office like they were candy. I could put a jar of them in place of jelly beans on the desk and have them disappear in a week. No failures, or at least no complaints for the cords so far. Big problems with cheap chargers, both AC and automotive. There's lots of junk out there. I had to run around and confiscate some 12V chargers I gave away for holiday gifts because they were a short/smoke/fire hazard.   Incidentally, this is a good USB car charger: <http://802.11junk.com/jeffl/Powergen%20USB%20car%20charger/Powergen%20USB%20car%20charger.jpg>   >> 6.8 years.   >Hence my inquiry here. >How often do *you* replace a micro-USB cable, Jeff?   I really don't know but close to zero for any kind of connector failure. I tend to loose cords, but not destroy them. When I do repairs, it's mostly replacing the receptacle on the phone, which is beyond the abilities of most of my customers. For my own equipment, I usually have 3 chargers per device (office, home, car). Of those that use micro-USB charging (2 phones, 4 BT headsets, 2 tablets, Kindle), I have never needed a replacement cable. On some of the junk I buy at garage sales, flea markets, and from customers, some of them required replacement, but mostly because they were in some way abused. Teeth marks from kids and animals are common.   >> I occasionally see some problems caused by rubberized phone "protectors".   >Not using a case or protector. >Thanks.   Some Samsung phones have removable backs that let you inspect the micro-USB receptacle. If your unspecified model Samsung is like that, you might check if the two halves of the metal frame have seperated, thus reducing the retention force and changing the pin alignment.   Also, you might try disclosing the Samsung phone model number. Different phones tend to have specific problems. Also, are you doing anything unusual while charging, such as charging the phone while it's sitting on a car seat while bouncing down the road or anything that might cause movement of the connector while charging? An excessively loose connector will make that worse. You might compare your retention force with a different phone and micro-USB connector pair.   -- 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

DaveC <not@home.cow>: Jul 05 08:17AM -0700 On 5 Jul 2016, Jeff Liebermann wrote:   > Also, you might try disclosing the Samsung phone model number.   Sam Galaxy S3.   > might cause movement of the connector while charging? An excessively > loose connector will make that worse. You might compare your > retention force with a different phone and micro-USB connector pair.   I use it while charging, sitting on the couch or lying in bed. The cable/phone does get moved around. But for 6 weeks this isn't a problem. So I rule out the phone's connector as cause. A new cable fixes the issue.   Thanks.

frank <frank@invalid.net>: Jul 05 02:50PM Hello all, really trying my luck here: does anybody have a DATA I/O 21A (E)EPROM programmer and can help me with some tests to understand if mine is working well? It appear to program most common EPROMs just fine but failed on the uncommon MCM68764 which I believe is good instead (but I have only one...). Sure, the MCM is a 1980 vintage, but it was NOS. Anyone? Thanks Frank IZ8DWF

coffee.java.beans@gmail.com: Jul 05 01:22AM -0700 I have had a scope sitting idle for about 8 years and am about to power it up.   Should I use a variac and build up the voltage slowly. or just power it up?   Any suggestions will be welcome.

jurb6006@gmail.com: Jul 05 02:03AM -0700 The dim bulb tester is a better option. You just put a 1000 watt incandescent in series with the power line. It limits current so if something is shorted it will not cause further damage. In fact on a scope you might want to use a 60 instead. The 100 watt is more suited for like audio amps in the 200 WPC range, the scope does not pull nearly as much.   Tektronix scopes are not known for having deadly shorts. Their power supply design is like "interdependent" sometimes only using one Zener for one source, like the -50 volts that has a very light load and using that as a reference for all the other sources. Also, since in a scope the current drain on each source can be calculated quite accurately, it is designed only to put out the current necessary, making smoke alot less likely.   Problem with variacs is they do not limit current. At what voltage do you expect to see a trace ? Nobody knows really. With the DBT it should reach full voltage fairly quickly.   Though unlikely with a Tek, it may be possible with a variac to cause a condition where the CRT bias is not right and cause a screen burn. If there are no shorts, the DBT should allow it to get full voltage and you won't have that problem.   All it takes is a standard light fixture, incandescent lamp, standard outlet and an AC power cord. Or, you could just pull the main fuse and clip lead the DBT there. On many units you can just leave the power switch off and jump it with that but don't, don't because there are so many weird designs out there and Teks are full of them. They had some REAL engineers. So just use the plug and cord method.   Only eight years ? I give it a 90 % chance of just firing up and working fine. Might need some filters but they probably won't be shorted, and that is really the only issue. Other things don't just short out from sitting unused. But there could be some that need to be replaced. We had to replace like ten of them in one to get the hash out of the trace, but none of them were shorted. What was that ? I think a 2225. A good scope but not one of my favorites. I prefer a 465.   I am downloading the manual now from bama.   __________________________________________   OK, I see it is a digital scope. In that case I would say not to use a variac on it. It might damage the data/program. I got that problem in an HP spectrum analyzer and you just can't get a flash for it, and your scope being from 1988 if you ask Tek for anything about it the will tell you to pound salt.   If the bulb does not dim in a few seconds, turn it off, take the cover off and then locate the power supply, plug it in directly and look for signs of heat. I mean take your finger and see what is getting hot. Don't let the thing dangle at half voltage or whatever. The most valuable thing in there is the data, as they cannot be replaced. Maybe in 1989, but not today.   Good luck.

jurb6006@gmail.com: Jul 05 02:05AM -0700 Oops, of course I mean 100 watts.   The debounce on this laptop is terrible. And I can't see worth a shit, and it was scrolled off by the time I hit the button.

"Tom Del Rosso" <fizzbintuesday@that-google-mail-domain.com>: Jul 04 12:49PM -0400 DaveC wrote:   > Pins 12 and 13 have a little triangle next to the pin; pins 1, 2, 15, > 16 have what looks like an "n"; 3 and 14 have an "x".   > What's the meaning of these marks?   That's the IEEE standard schematic notation touted by TI in the 80's. The downward sloping triangle means logical inversion, or active-low. I don't remember the others.

N_Cook <diverse@tcp.co.uk>: Jul 04 06:49PM +0100 On 04/07/2016 17:49, Tom Del Rosso wrote:   > That's the IEEE standard schematic notation touted by TI in the 80's. > The downward sloping triangle means logical inversion, or active-low. I > don't remember the others.   In that case "x" means don't care

Tauno Voipio <tauno.voipio@notused.fi.invalid>: Jul 04 09:11PM +0300 On 4.7.16 18:26, DaveC wrote: > what looks like an "n"; 3 and 14 have an "x".   > What's the meaning of these marks?   > Thanks.     The 'n' pins are non-logic signals. The 'x' pins are power supply pins, see the chip data sheet.   --   -TV

Don Y <blockedofcourse@foo.invalid>: Jul 04 11:22AM -0700 On 7/4/2016 8:26 AM, DaveC wrote:   > Pins 12 and 13 have a little triangle next to the pin; pins 1, 2, 15, 16 have > what looks like an "n"; 3 and 14 have an "x".   > What's the meaning of these marks?   The little triangle (sort of like half an arrowhead?) denotes active low (what used to be indicated by a "bubble"). The tip of the arrow indicates the direction of signal flow. Can appear on a gazinta or a cumzouta.   A (real!) triangle inside the device outline denotes a dynamic/clock input (edge)   The "n" (actually, more like an upside down U) denotes an analog signal (look at the device and you can see why this is so!) when encountered on a digital signal; a '#' indicates a digital signal when encountered on an analog signal.   The 'x' indicates a "non-logic" signal (in yor case, the reference gnd)   There are other markings that indicate postponed outputs, tristate outputs, open-collector, open-emitter, hysteresis, etc.

DaveC <not@home.cow>: Jul 04 12:44PM -0700 > It looks like they are saying these pins go to the AC ground bus.   As denoted by the huge triangle (left of the junction) and "ACGND"...   Why would the designers put those small triangles there if the connection and label already make this obvious?

DaveC <not@home.cow>: Jul 04 12:45PM -0700 On 4 Jul 2016, Don Y wrote:   > (look at the device and you can see why this is so!) when encountered on > a digital signal; a '#' indicates a digital signal when encountered on > an analog signal.   ??   "when encountered on"? So both of these pins are mixed-signal? "n" is mostly-digital and # is mostly-analog? (c;

DaveC <not@home.cow>: Jul 04 01:04PM -0700 Datasheet: http://www.analog.com/media/en/technical-documentation/data-sheets/AD7524.pdf   Pins 12, 13 are latch enables that aren't used so tied to ground. The tiny "triangles" are probably enable-low indicators.   Still not sure about "n", "#", "x"...   -=-=-=-   On 4 Jul 2016, I wrote:

krw@attt.bizz: Jul 04 04:40PM -0400 >As denoted by the huge triangle (left of the junction) and "ACGND"...   >Why would the designers put those small triangles there if the connection and >label already make this obvious?   Which triangles are you talking about? The triangles on the power pins simply denote a global (power) connection. That's all.   The wedges where the pins connect to the body denote an inverted pin, or a "logic low active" signal. The fact that these are grounded simply means that these signals are tied "active".

DaveC <not@home.cow>: Jul 04 02:11PM -0700 > The wedges where the pins connect to the body denote an inverted pin, > or a "logic low active" signal. The fact that these are grounded > simply means that these signals are tied "active".   Yeah, those.   Thanks.

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