- Replace Li-Ion cells in battery pack? - 11 Updates
- Consumer electronics "war stories" - 14 Updates
| Clifford Heath <no.spam@please.net>: Dec 11 12:22AM +1100 On 11/12/15 16:09, Percival P. Cassidy wrote: > I've taken it apart and found that it has five pairs of cells that are > labeled: > "LS IMR-18650BB 18650 is the physical geometry: 18mm diameter, 65mm long, 0=round. Any Li-ion 3.7V 18650 will do as a replacement (peak charge voltage 4.2V) - but get a matched set of 5. > I see on line numerous variants of the 18650 cells with various mAH > ratings but nothing with the "BB" suffix. It's meaningless as far as you're concerned. > Is it worth the effort of trying to replace the defective pair, or is > there a way that I could try to restore them to life? No. Replace the lot - you don't want a mis-matched string. > I don't have a spot-welder. If I use a Dremel cutting wheel to cut the > tabs on the defective pair, would it be OK to solder new ones in place > using copper flashing? Buy replacements with tabs on. Soldering can damage the cell internally unless you're very skillful and swift. Avoid Ultrafire and other *fire Chinese brands and their Chinese clones (often repackaged dead cells). They make fantastical claims of capacity, but you're lucky if you get 1000mAH, and never as much as 2000mAH (they often claim 4000 or 6000; no-one can build that). If you can afford it, buy Panasonic NCR cells - about $12-$15/ea - which if genuine will produce about 3400mAH at a much better sustained voltage. Chalk and cheese against the Chinese cells. Clifford Heath. |
| "Percival P. Cassidy" <Nobody@NotMyISP.net>: Dec 11 12:09AM -0500 have an 18V 2.4AH battery pack for Ryobi power tools that will no longer take a charge and that the charger indicates is defective. I've taken it apart and found that it has five pairs of cells that are labeled: "LS IMR-18650BB YT0288.<different numbers on the ones I can see> Made in China" I see on line numerous variants of the 18650 cells with various mAH ratings but nothing with the "BB" suffix. Four of the pairs of paralleled cells show a voltage of 4.1x; the other pair shows 2.1mV. Is it worth the effort of trying to replace the defective pair, or is there a way that I could try to restore them to life? If I want to replace the defective pair, I assume that any 18650 cells with at least 1200mAH capacity will work -- but in fact I don't see any that low. I don't have a spot-welder. If I use a Dremel cutting wheel to cut the tabs on the defective pair, would it be OK to solder new ones in place using copper flashing? Perce |
| mike <ham789@netzero.net>: Dec 10 10:11PM -0800 On 12/10/2015 9:09 PM, Percival P. Cassidy wrote: > YT0288.<different numbers on the ones I can see> Made in China" > I see on line numerous variants of the 18650 cells with various mAH > ratings but nothing with the "BB" suffix. There are many variants of cells. The ones designed for high current have lower capacity. If you try to use laptop high capacity cells in a drill, you'll have low performance and short service life. You're likely to find that the correct cells you need cost about the same as a new pack. > pair shows 2.1mV. > Is it worth the effort of trying to replace the defective pair, or is > there a way that I could try to restore them to life? You can try to charge the dead pair with a 4V power supply current limited to 100 ma or so. Always wear eye protection! Don't get in a hurry, or you may set the thing afire. Do it in the garage in a bucket that can't burn if the cells catch fire or explode. I've had limited success with that in laptop packs. But don't get your hopes up. If it works, charge each pair individually to the same voltage. Don't get in a hurry, it may take a long time for the current to drop. > If I want to replace the defective pair, I assume that any 18650 cells > with at least 1200mAH capacity will work -- but in fact I don't see any > that low. NO, get the right type of HIGH current cells and replace them all. > I don't have a spot-welder. If I use a Dremel cutting wheel to cut the > tabs on the defective pair, would it be OK to solder new ones in place > using copper flashing? DO NOT SOLDER DIRECTLY TO ANY CELL OF ANY KIND. You can solder tabs together, if you're quick about it. > Perce What's your objective? If you want to play with battery packs, you're on the right path. If you want to drill holes reliably, call up Ryobi and buy a new pack. Last year at this time they all seemed to have lifetime battery guarantee. |
| mroberds@att.net: Dec 11 08:01AM > I have an 18V 2.4AH battery pack for Ryobi power tools that will no > longer take a charge and that the charger indicates is defective. If you're in the US, you might check with your local Batteries Plus store. I had some DeWalt 12 V NiCd packs rebuilt by them for pretty reasonable money, a couple of years ago. They have cells with tabs, and the spot-welder to correctly join the tabs together. Home Depot sells a brand new Ryobi P105 battery - probably the same one you have - for $59+tax. That listing also claims that the battery has a 3-year warranty; is it possible that your battery is younger than that? Standard disclaimers apply: I don't get money or other consideration from any companies mentioned. Matt Roberds |
| "Percival P. Cassidy" <Nobody@NotMyISP.net>: Dec 11 11:05AM -0500 On 12/10/2015 08:22 AM, Clifford Heath wrote: > 18650 is the physical geometry: 18mm diameter, 65mm long, 0=round. > Any Li-ion 3.7V 18650 will do as a replacement (peak charge voltage > 4.2V) - but get a matched set of 5. If I have to get a matched set -- of ten (five *pairs*) -- rather than of two, I might as well get two 4AH ones for $99. >> Is it worth the effort of trying to replace the defective pair, or is >> there a way that I could try to restore them to life? > No. Replace the lot - you don't want a mis-matched string. See above. |
| "Percival P. Cassidy" <Nobody@NotMyISP.net>: Dec 11 11:13AM -0500 On 12/11/2015 12:51 AM, Jeff Liebermann wrote: > <https://www.google.com/search?q=balance+charger> > The technique is SLOOOOOWLY creeping into the power tool biz. > <https://en.wikipedia.org/wiki/Battery_balancing> This battery pack does have connections from every between-cells connection to the PC board, so I am assuming that this was supposed to be part of the balancing circuitry. I can buy two of the 4AH packs for $99, so replacing all ten cells (five *pairs*) in the present one would probably cost about the same for less capacity as one new one. Perce |
| "Percival P. Cassidy" <Nobody@NotMyISP.net>: Dec 11 12:34PM -0500 > store. I had some DeWalt 12 V NiCd packs rebuilt by them for pretty > reasonable money, a couple of years ago. They have cells with tabs, > and the spot-welder to correctly join the tabs together. I did ask at my local Batteries Plus, who told me that they don't rebuild Li-Ion battery packs. Their after-market battery packs are outrageously expensive. > you have - for $59+tax. That listing also claims that the battery has > a 3-year warranty; is it possible that your battery is younger than > that? The defective one is a P104, and I have no idea when I bought it. Even if it were, theoretically, in warranty, I've voided the warranty by taking it apart and peeling off the adhesive foam covering the ends of the cells; it never occurred to me that it *might* still be in warranty. It appears that Ryobi warranty service is obtained by returning items to a service center -- no indication that one can simply exchange a defective item at Home Depot. A two-pack of the 4AH P108 packs is only $99. I don't know whether that's a year-round deal, but I did take advantage of the same deal around this time last year. I suspect that's a year-end deal, as a single P108 is the same price. Perce |
| "Percival P. Cassidy" <Nobody@NotMyISP.net>: Dec 11 03:52PM -0500 On 12/11/2015 12:59 PM, Jeff Liebermann wrote: > This might be of interest if you want to repair your battery pack: > "Cell Re-balance of Ryobi One+ 18V Li-ion Battery (130501002)" > <https://www.ifixit.com/Guide/Cell+Re-balance+of+Ryobi+One%2B+18V+Li-ion+Battery+%28130501002%29/13286> I might try that. > <http://toolboyworld.com/eBay/Ryobi_Batt_Rebuild.htm> > Looks like the balancing circuitry is in the battery pack, not the > charger. He deals with minor voltage differences between cells, not the huge differences I have (mV only, from the one paralleled pair). > I would not trust the battery capacity (ma-hrs) as stated on the > label. However the goood price and less risk of buying these is > probably better than trying to rebuild a pack. Any less trustworthy than the alleged 2.4Ah capacity of the present one? Perce |
| "Ian Field" <gangprobing.alien@ntlworld.com>: Dec 11 09:26PM "Jeff Liebermann" <jeffl@cruzio.com> wrote in message news:71ok6b5hggqf5ujg249gcaca91dk5uupji@4ax.com... >>using copper flashing? > The cases on most 18650 cells are stainless steel. You won't be able > to solder to those. The flux I bought in a plumbers supply yard works perfectly OK on stainless, but sometimes needs the stainless to be lightly abraded. Often I see a warning on lithium cells not to expose to more than 212F - or boiling water in other words. Whenever I need to solder lithium cells; I just trim back the stainless strip so it still has a bit spot welded to the cell - its just that little bit more thermal resistance between the iron and the cell. A fully charged cell can provide a fair bit of entertainment if the heat of soldering melts the seal and causes a short - solder first, charge later. |
| "Percival P. Cassidy" <Nobody@NotMyISP.net>: Dec 11 07:17PM -0500 On 12/11/2015 12:59 PM, Jeff Liebermann wrote: > <http://toolboyworld.com/eBay/Ryobi_Batt_Rebuild.htm> > Looks like the balancing circuitry is in the battery pack, not the > charger. I tried boosting the voltage of the low-voltage pair but without much success so far. I don't really have a suitable power source. When I plug that pack into a P117 charger, the red light flashes "for ever" ("Testing"), but after a looong time changes to the slow flash indicating "Defective." When I plug it into a P125 charger, I get the "Charging" indication for just a minute or two, then it switches to "Charged," but of course it isn't: that one pair of cells still shows only in the mV range. Perce |
| mike <ham789@netzero.net>: Dec 11 06:22PM -0800 On 12/11/2015 1:22 PM, Jeff Liebermann wrote: > I made my own CD (capacitor discharge) system, but it sucks and is in > need of replacement. > Good luck. It's not clear how those welders work. Looks like timed pulse?? I spent a LOT of time messing with battery tab welding. You need a LOT of heat QUICKLY. I put a SSR on the primary of a modified microwave oven transformer and counted the number of cycles of 60 Hz. to set the power delivered. Problem with low voltage is that it is extremely sensitive to resistance in the path. I could get very good welds about 80% of the time. On average, I got all good welds on about 0% of the packs. You really want a fixed amount of energy delivered independently of contact resistance. Capacitive discharge is the way to go. But, to get repeatability, you need to be switching the energy at high voltage. It's not easy to switch 1000 amps or more. I gave up on DIY when I found a 125 Watt-Second CD system on ebay for cheap. That puppy can put 7000A single pulse into .001 ohms. Repeatability improved dramatically. Battery doesn't even get warm. |
| Trevor Wilson <trevor@SPAMBLOCKrageaudio.com.au>: Dec 04 06:49AM +1100 On 3/12/2015 11:34 PM, Mark Zacharias wrote: > Any more recent successs stories to brag about? > C'mon, don't we all enjoy patting ourselves on the back, really? > Mark Z. **I recall the first time (1980-ish) I discovered those fusible resistors that go high after a few years. With no obvious signs of distress. Now I just head straight for the buggers. Then there's those low value (</=47 Ohms), 1/4W cracked carbon resistors that go O/C when subjected to ca. 60+ Volts with no signs of burning (Marantz 1200b, 240, 250M, 500 models). Over the years, I learned to suspect any resistor over the value of 100k, if the circuit is displaying some kind of mysterious fault that cannot be explained by a semiconductor failure or cap leakage. -- Trevor Wilson www.rageaudio.com.au --- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus |
| etpm@whidbey.com: Dec 03 03:53PM -0800 On Fri, 4 Dec 2015 06:49:10 +1100, Trevor Wilson >suspect any resistor over the value of 100k, if the circuit is >displaying some kind of mysterious fault that cannot be explained by a >semiconductor failure or cap leakage. That resistor story is interesting. About two years ago I had a linear power supply fail in one of my CNC machines. I did the troubleshooting bit and discovered a bad -15 volt regulator. So I replaced it and then a few weeks later something else went bad and I couldn't find it. I took it to a friend who is an electronics engineer and he discovered an open resistor. I asked why he checked it because there was no visual reason for it to be bad. It wasn't cracked or discolored. He said that's what he usually did first, check for open resistors. He said it was a common fault. Since then the power supply has been operating fine. Eric |
| amdx <nojunk@knology.net>: Dec 03 07:34PM -0600 On 12/3/2015 6:34 AM, Mark Zacharias wrote: > C'mon, don't we all enjoy patting ourselves on the back, really? > Mark Z. I posted this an hour ago, but it hasn't shown up, so I'll do it again. Back 30 years ago I stopped at a consumer electronics/TV repair shop and presented my resume. I had been to many manufacturer service training seminars and had a hand full of certificates of completion. The owner looked it over and said, "I just hired a guy, I wish you came in earlier." So I went home and about 45 minutes later he called and said, "I see you have a lot of Sony training, I have this projection TV in here that nobody can fix, I'd be happy to pay you for looking at it." So I drove down and got the manual, noted the problem was, no output from the 3 tubes. I started poking around in the HV section, and within minutes the owner said, hey you got it working! I didn't know it was working ;-} I put my head out front and it had an output. Hmm, I unhooked my scope probe and the picture went with it. From there, we, more he, figured out one of the other techs replaced a cap with 1/10 the proper value, the scope probe hanging on the test point had enough capacitance to make the set work. He hired me that day, it was good, within two blocks of my house. So, I got a job by accident. Mikek |
| Chuck <ch@dejanews.net>: Dec 04 12:21PM -0600 On Thu, 3 Dec 2015 06:34:55 -0600, "Mark Zacharias" >Any more recent successs stories to brag about? >C'mon, don't we all enjoy patting ourselves on the back, really? >Mark Z. The receiver tech was flummoxed by one of those large 1970s Pioneer receivers. It had a problem none of us had seen before and we were a high volume audio chain. There was slight audio distortion on both channels, only on FM. We all worked commission only so I was the only one to volunteer to help him out. To cut to the chase, the receiver had an over designed mute circuit that was 3 or 4 stages deep, At the deepest stage there was one of the Sanyo electrolytics that became a common failure item many years later which was slightly leaky. I've got another one. In the early 80s there were these 19" Hitachi tvs that ghosted. It looked exactly like a bad delay line. By that time I ran the TV service department for the same company. We had just switched over to the big box store concept and I was inundated with broken tvs. Out of desperation, I switched out the CRT and the ghosting disappeared. We sold 1000s of these sets and I saw the problem 3 more times. And another. Kenwood sold these Funai made cd changers that never worked properly. All of them would come back with skipping or not playing discs problems. Kenwood came out with 3 or 4 mods, none which worked. Sometimes they would work for months before they came back. Somehow I found out if the mechanism retaining springs were stretched so the mechanism didn't sag at all, the problem disappeared. Called up Kenwood and they put out a mod kit that included strong springs which also didn't allow any downward movement of the mechanism. Last one. There were these very expensive ADS cd players which would play any disc except a ,very popular at the time, Jimi Hendrix Ryko disc. Couldn't find any electronic or mechanical problems. I slightly moved the CD turntable slightly down on the spindle and this disc and all other discs would play. --- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus |
| amdx <nojunk@knology.net>: Dec 04 02:28PM -0600 On 12/3/2015 6:34 AM, Mark Zacharias wrote: > Any more recent successs stories to brag about? > C'mon, don't we all enjoy patting ourselves on the back, really? > Mark Z. In the late 80s early 90's I worked on VCR's. The Fisher FVH 906, had a tuner that went defective, no schematic, a replacement part only. That's ok under warranty, but after that, the part cost was to high to get a repair ok. So one day, I decided to see if I could find out what the cause of the failure was. I started spraying parts with freeze mist and found when I hit a 1uf 35V cap the picture came back. I made a lot of repairs, replacing that same cap on a whole bunch of tuners. I'd do the same thing every time, dribble 2 or 3 drops of freeze mist on the cap and the picture came in. I had a customer bring in a remote for repair, it checked out fine. He took it home and called saying it didn't work. I talked to him a bit and found he had just install new CFL lights. I suggested he shield that light and try it. It worked, I had just read about that in a trade magazine two days previous. Mikek I got in early on the VCR curve, they were expensive, commanding high service rates, then when prices dropped we had a high volume of repairs, rode it down until the price was close to $200, then I moved to Florida. A year later the tech that took my place said he came in a couple days a week to repair the few that came in. I repaired a little over 11,000 vcr's in ten years, it was a good time. |
| mroberds@att.net: Dec 11 07:41AM > Maybe we could share some "war stories" of cool repairs we have done > in the past. It's definitely not consumer electronics, but here goes. I used to work at a company that made flight simulators. My official job was writing code to make the navigation instruments display correctly, according to the simulated position of the aircraft, which frequencies the radios were tuned to, the position of circuit breakers, etc. Some of the laws of nature at that particular job included: 1) Techs string wire. 2) Programmers write programs. 3) Techs never make mistakes when stringing wires. 4) No programmer could ever possibly understand the intricacies of stringing wires. Therefore, any complaints by programmers about the wiring can usually be disregarded. 5) Any persistent complaints about the wiring can be remedied by telling the programmers to work around it in the code. Never being one to obey the laws of nature, I brought in my own meter and checked things out when the sim didn't seem to work right. My boss knew that I had something of a clue; I had been giving "how to read a schematic" lessons to a few of my cow-orkers (in software) who were also new hires or just wanted to know how. He basically told me that he didn't mind me doing my own checks as long as I was careful with the sim hardware, and that I should expect the techs to get mad at me if they ever saw me doing it. I couldn't get the right DME indicator to light up in one sim. (It was a box in the instrument panel with three 7-segment displays and a couple of buttons. It was supposed to display how far the airplane was from a particular radio station.) After a few rudimentary checks of my code, I wrote up a "right DME inop" trouble ticket. The technician wrote back, "Wiring checks to print, DME sent for repair". Sure enough, there was a hole in the panel. When it was again filled, I tried again...no joy. I swapped the left and right indicators - hmm, the problem stayed with the socket instead of following the indicator. I broke out the wiring diagram and my own personal multimeter and started chasing around behind the panel - no wires or pins for power on the right DME socket. (It was something like a DB25 or DB37, with individual "crimp and poke" contacts.) I dutifully re-opened the ticket, and the tech dutifully wrote "wiring checks to print" and closed it again. About this time, the sim was shipped to the site, even though it was broken. The standard process was to completely build the sim at the factory, test it out, ship it to the site, certify it, and put it in revenue service. For sites that were far away from the factory, this practice was generally followed, because it was expensive to ship people to site to finish working on the sim. However, the site that was closest to the factory (~3 hr drive) was notorious for the following: Factory: We will have the sim done on $DATE. Site: No no no! We've already sold time on that sim to customers on $DATE-30days and we can't reschedule! We *must* have it here sooner! Factory: Why did you do that? The sim will not be done on $DATE-30days. It will be broken and unusable for training. Site: We don't care. Factory: If we ship it at that time, it will suck. Site: We don't care!!! Ship it shipit SHIPIT!!1! Factory: <sigh> OK. (time passes) Site: Well you got the sim to us on time but it sucks! Everything's broken and we can't put the customers on it! Fix it fixit FIXIT!!1! Factory: <sighs deeply, starts phoning rental car agencies and hotels> So I get to the site and the site manager is bugging me about the right DME indicator. I walk in to the site maintenance shop and tell the techs there I need some connector pins, the crimper tool, some wire, and a bench power supply. They are extremely wary of this as they have experienced "programmers with screwdrivers" before, but they give me the requested items and follow me into the sim, probably in hopes that my body will shake and jerk in interesting ways as I electrocute myself. I put the pins on the wires and put them in the (still vacant) slots on the right DME connector. Wires run out under the panel to the power supply, which temporarily gets the co-pilot's seat. Fire up the sim, hit the power supply, and whaddayaknow - DME love for all. I disappointed the techs, but the site manager was very happy. I pointed out the relevant page in the wiring diagram book, so the site techs could get it wired in correctly. I figured they had a lot more experience than I did in fixing factory screwups. They were satisfied with this, and I got to go home. Matt Roberds |
| Mike Tomlinson <mike@jasper.org.uk>: Dec 11 08:43AM > Site: Well you got the sim to us on time but it sucks! Everything's > broken and we can't put the customers on it! Fix it fixit > FIXIT!!1! Why does that sound so horribly, horribly familiar? Brrr. Memories I'd rather forget. -- (\_/) Tyson Fury: #homophobe #bigot #throwback #missinglink (='.'=) #neanderthal #misogynist #redneck #dickhead (")_(") |
| "Mark Zacharias" <mark_zacharias@sbcglobal.net>: Dec 11 05:27AM -0600 <mroberds@att.net> wrote in message news:n4dume$d8b$1@dont-email.me... > experience than I did in fixing factory screwups. They were satisfied > with this, and I got to go home. > Matt Roberds Wow. Lots of times I'm too lazy to read to the end - but this was great! Loved it! mz |
| c4urs11 <c4urs11@domain.hidden>: Dec 05 10:17AM On Thu, 03 Dec 2015 06:34:55 -0600, Mark Zacharias wrote: > Maybe we could share some "war stories" of cool repairs we have done > in the past. Somewhere in the eighties we installed a custom-built control system in a 24/7 assembly line for SIL ceramic hybrid circuits. Subcontractor of subcontractor job. One night I was called in for an unexpected stop. Inside the plant I was 'greeted' by the crowd of tech support people and blaming managers gathered around our equipment. On my way to the control system I came across one of the typical mushroom emergency stops along the production line. By habit I twisted the knob and felt the release spring. I worked my way to the control panel and engaged the start. Within seconds the crowd silenced and fled the scene: the line was up. We were never again called in. |
| "Mark Zacharias" <mark_zacharias@sbcglobal.net>: Dec 11 06:02AM -0600 How about another slant on "War Stories" ? The least competent, most alcoholic, etc tech person you ever had to work with or follow after they got fired? When I was first starting in consumer electronics repair, (my first job in the business, actually) I was hired to replace "Karl". He had a resume - in the '70s a well respected shop paid for him to come over from Germany. By my time however - apparently a broken down alcoholic. He would "repair" tons of stuff, bill out huge amounts (paid on commision) then abscond when the re-do's became too much. I was charged with fixing his re-do's and generally cleaning up the chaos he had left behind. Next job - another shop. They had just fired the SAME GUY. Same situation. Re-do's coming in one after another. Angry customers. Piles of screws and small hardware in a pile on one corner of the bench. Dis-assembled units all over the place, and I mean ALL OVER. A Teac A-4010 in about four different parts of the shop. No pressure... I'd never even seen one before. Next job - SAME DEAL. By now I was getting pretty good at reverse-engineering other peoples screw-ups, but - really? A couple examples: Auto-reverse car cassette deck. He didn't have the correct drive belt, so he had SUPER-GLUED the ends of the old belt together. Played about 2 mnutes, if that. A Marantz 1060 integrated amp (re-do) with a blown channel. He had substuted a driver transistors with a similar package item. Unfortunately, the part he used was a VOLTAGE REGULATOR IC and not even a transistor. He had his "groupies" though. Some customers followed him from one job to the next. About 1987 Bang & Olufsen in Chicago contacted our shop for a reference on this guy. We were rolling on the floor! Gave him an absolutely GLOWING reference. We could think of nothing funnier than the prospect of this guy working for B&O. (no he didn't get hired) Good times. |
| "Mark Zacharias" <mark_zacharias@sbcglobal.net>: Dec 05 06:52AM -0600 Things that are second nature to us now were "learning experiences" back then, yes? At my first job as a tech, about the second piece I ever worked on was a Pioneer SX-828. Yup - the infamous "blue Sanyo cap" scenario. Except I had never heard of that and had no tech support or even a more experienced tech along side me. I was totally on my own, as I usually was during the first 15 or 20 years of my career. Symptom: one channel gone, just a low hiss. Preamp issue. Tracing signal - got it, don't got it, and so on. In the tone amp, DC voltage low at collector of one transistor. 1.5uF Sanyo coupling cap to base was leaky, driving that stage into saturation. Felt really good about that one. Mark Z. |
| "Mark Zacharias" <mark_zacharias@sbcglobal.net>: Dec 05 06:26AM -0600 "c4urs11" <c4urs11@domain.hidden> wrote in message news:1449310629.173856@news.evonet.be... > I worked my way to the control panel and engaged the start. > Within seconds the crowd silenced and fled the scene: the line was up. > We were never again called in. About 1981 I was still in tech school and not even really a technician yet. (I was SO green). Third semester, servicing phase. There was an old GE tube chassis color set with intermittent color sync. It was a "re-do" which the prior class had failed to fix correctly. I got to the burst gate amp and saw there was a much smaller signal at the grid than called for. Also, there was a neon lamp in the grid circuit which was supposed to drop 75 or so volts and the drop was much higher than expected, plus the lamp glowed somewhat faintly at it's base instead of lighting fully. I couldn't get the instructor to order a miserable 75 cent neon lamp. He kept me running around checking this cap or this resistor, etc. Finally I went around him to another instructor, explained my logic and got the lamp ordered. Fixed the tv. My instructor never really forgave me for that. Mark Z. |
| amdx <nojunk@knology.net>: Dec 05 01:07PM -0600 On 12/5/2015 6:52 AM, Mark Zacharias wrote: > saturation. > Felt really good about that one. > Mark Z. I had an SX-828, bought it sometime in the early 70s. Been so many years, I don't recall the problem, but I tossed it about two years ago, just too much stuff. Mikek |
| Chuck <ch@dejanews.net>: Dec 05 03:30PM -0600 For a very short time in the 1980s, Kenwood manufactured amplifiers with wrong value resistors at various locations. The first one was a bear because I had never seen a Japanese company make that kind of mistake. --- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus |
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