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oldschool@tubes.com: Feb 11 04:52AM -0600 I got an old AM-FM pocket transistor radio which looked good and clean till I opened the battery compartment. Very corroded carbon zinc batteries were in it. After removing them, I cleaned off as much of the corrosion as possible by scraping with a plastic stick, and scrubbing with q-tips and rubbing alcohol. That got rid of most of it, and I was surprised to find the battery clips are not badly damaged, but I had to use a fingernail file (sandpaper strip) on the ends of the springs.   Better yet, the radio works perfectly.   But there is still a little of that battery corrosion still in there. In all the years I've worked on electronics, I have never found a perfect way to clean up leaked batteries. Is there some sort of spray or a chemical that will dissolve or deactivate that crap?   Of course it has to be safe for the circuit board and components too. I use the 91% isopropyl alcohol, so it evaporates quickly and leaves little water residue behind. (Then leave it dry well before use).

"pfjw@aol.com" <pfjw@aol.com>: Feb 11 04:51AM -0800 > Of course it has to be safe for the circuit board and components too. I > use the 91% isopropyl alcohol, so it evaporates quickly and leaves > little water residue behind. (Then leave it dry well before use).   My sovereign cleaning method for this is to use a very strong concentration of baking soda mixed into distilled water. About a tablespoon of soda into a teaspoon of water to make a paste. This will neutralize any corrosives from the batteries - but the material is highly conductive in its own right. So, after application with a small toothbrush or spiral brush, rinse again as yo have with distilled water, then alcohol to displace the water.   If severe, and the alternative is landfill - I have been known to run an entire chassis through the dishwasher (one without an exposed Calrod), or use a bit of lye-based oven cleaner on a cotton swab - again rinse carefully when done. Needs must when the devil rides.   Peter Wieck Melrose Park, PA

Ralph Mowery <rmowery28146@earthlink.net>: Feb 11 10:23AM -0500 In article <0dfe8268-2fca-4597-9f0d-f2a98fd74c77@googlegroups.com>, pfjw@aol.com says... > > use the 91% isopropyl alcohol, so it evaporates quickly and leaves > > little water residue behind. (Then leave it dry well before use).   > My sovereign cleaning method for this is to use a very strong concentration of baking soda mixed into distilled water. About a tablespoon of soda into a teaspoon of water to make a paste. This will neutralize any corrosives from the batteries - but the material is highly conductive in its own right. So, after application with a small toothbrush or spiral brush, rinse again as yo have with distilled water, then alcohol to displace the water.   > If severe, and the alternative is landfill - I have been known to run an entire chassis through the dishwasher (one without an exposed Calrod), or use a bit of lye-based oven cleaner on a cotton swab - again rinse carefully when done. Needs must when the devil rides.   As most of the batteries used in portable devices are some type of alkaline the baking soda is the opposit of what should be used. White vinegar is what you should be using to neutralize it.   I am not sure what the very old carbon zinc batteries used, it may have been a from of acid. I know the car batteries use acid and the baking soda is good for that. Just not good for the newer smaller AA,C,D type batteries.

John-Del <ohger1s@gmail.com>: Feb 11 07:27AM -0800 > If severe, and the alternative is landfill - I have been known to run an entire chassis through the dishwasher (one without an exposed Calrod)   Back when projection TVs were plagued with coolant leaks, I used to soak the entire circuit board in an ammonia and soap solution. But *first*, everything that can trap water must be removed. Back then, that meant SMPS transformer, HOT and flyback XFRs, inductors,etc. A lot of work but it fixed stubborn symptoms and no call backs.   In a transistor radio, this means removing the IF transformers, audio transformer, and even removing the gang tuner is a good idea.

bruce2bowser@gmail.com: Feb 11 02:47AM -0800 On Friday, February 2, 2018 at 12:17:37 PM UTC-5, Jeff Liebermann wrote:   > >Can someone explain to me how you lose (and then find) a satellite? > >https://www.washingtonpost.com/news/inspired-life/wp/2018/02/01/this-amateur-astronomer-found-a-satellite-lost-in-space/   > Sure. When funding runs out, the satellite gets lots.   Lost, you mean?

Mike Coon <gravity@mjcoon.plus.com>: Feb 11 02:40PM In article <b5723a31-9f46-42ea-b25a-4a9b739bb85b@googlegroups.com>, bruce2bowser@gmail.com says... > > >https://www.washingtonpost.com/news/inspired-life/wp/2018/02/01/this-amateur-astronomer-found-a-satellite-lost-in-space/   > > Sure. When funding runs out, the satellite gets lots.   > Lost, you mean?   Probably loses its slot, too...   Mike.

tabbypurr@gmail.com: Feb 10 05:44PM -0800 On Saturday, 10 February 2018 01:09:54 UTC, Jeff Liebermann wrote: > evaporation) and is not a spray. A Q-tip might be best for swabbing > in your ear. Let us know if it reduces the noise level and improves > the SNR (signal to noise ratio) in this newsgroup.   Well I'm not an earologist, but I presumed more would get on the eardrum if it were sprayed in, hence the suggestion of sorts. And if some does, it's bound to reduce noise, to some degree.   NT

"pfjw@aol.com" <pfjw@aol.com>: Feb 11 04:44AM -0800 Quick fix (Pat. Pend.):   a) Obtain one small container of low-grade, but pure Olive Oil. b) Obtain a small container of Zippo lighter fluid (made in Bradford, PA). c) Obtain a small package of cotton swabs.   In a small dish, mix nineteen (19) drops of lighter fluid with one (1) drop of olive oil.   Saturate the end of one cotton swab in the material.   Stick it in your ear!   Peter Wieck Melrose Park, PA

jurb6006@gmail.com: Feb 11 01:25AM -0800 Got all these old tapes we made. Not much on TV these days, new shows are all cops and robbers or murders, or surreal movies or really terrible sitcom reruns, very few of which were any good in the first place. Plus I got too much time on my hands.   Sometimes it works, then not. Displays a bunch of error codes and I am having trouble finding out what they mean. It has L 07 11, L15 60, L 18 11, L 00 11.   If it ejects it seems fine, until it doesn't. Then after while it ejects and then is OK, but if plugged in with a tape in it, it is really uncooperative.   The 11 code on the end has something to do with the eject not being complete. Couple of other codes have to do with not being able to tell what mode it is in or something.   So I am thinking mode switch which is the colloquial term used by VCR tech for the mechanical state switch. However I am having trouble figuring out how to get it out to clean it. I already resoldered the connector to it on the board, no good. It worked a few times and then threw up an error code, not sure which, it seems to like to throw about 4 different ones at random.   Right now there is a tape in it so it will probably not work until tomorrow, and that is where it does not sound like a mode switch. I've never heard of a switch going thermal.   This sounds like something that was in a service bulletin from Sony a long time ago, I got 2 with this problem. The other is a 740 but inside they are identical. The 740 is a sacrificial goat because it has other problems and some corrosion from being in a bad environment.   Anyone remember working on these things ? Actually I was out of it when they came out and working on bigscreens mostly, so when they were newer I never worked on one.   Any ideas appreciated. I want to watch my old tapes !

"Gareth Magennis" <soundserviceleeds@outlook.com>: Feb 10 09:58PM wrote in message news:2tso7d9m02shd9cmfoatev1j55rpilg12n@4ax.com...   I have a laptop that is acting really weird. It's an older ASUS, probably ten or twelve years old. It was plugged in, closed, sitting on a table. It worked fine a few days before the problems started. The display keeps shaking. The machine takes forever to boot up. And then acts weird. But if I push down hard on the lower left side of the machine it works fine. As long as the pressure is kept up and in just the right area. I spoke to my son about this problem because he knows more about this kind of thing than I do. He said it sounded like a video card problem that he and some of his computer whiz friends have run into. Apparently the video processor can get too hot and the BGA under it can start to debond. He has a hot air rework tool and he said I might be able to reflow the chip. Is this something that a rank amateur can likely do? Eric

"Gareth Magennis" <soundserviceleeds@outlook.com>: Feb 10 10:03PM It's worth a go if the laptop is scrap otherwise.   Chances of success are extremely slim though.     The success stories you see on Youtube are either fake, or the tiny percentage of these repairs that lasted long enough to make the video.       Gareth.               wrote in message news:2tso7d9m02shd9cmfoatev1j55rpilg12n@4ax.com...   I have a laptop that is acting really weird. It's an older ASUS, probably ten or twelve years old. It was plugged in, closed, sitting on a table. It worked fine a few days before the problems started. The display keeps shaking. The machine takes forever to boot up. And then acts weird. But if I push down hard on the lower left side of the machine it works fine. As long as the pressure is kept up and in just the right area. I spoke to my son about this problem because he knows more about this kind of thing than I do. He said it sounded like a video card problem that he and some of his computer whiz friends have run into. Apparently the video processor can get too hot and the BGA under it can start to debond. He has a hot air rework tool and he said I might be able to reflow the chip. Is this something that a rank amateur can likely do? Eric

Ralph Mowery <rmowery28146@earthlink.net>: Feb 10 05:27PM -0500 In article <gWJfC.491707$q8.254294@fx07.am4>, soundserviceleeds@outlook.com says... > He has a hot air rework tool and he said I might be able to reflow > the chip. Is this something that a rank amateur can likely do? > Eric     You can give it a try.   Here is one opinion on the reflowing.   https://www.youtube.com/watch?v=E9aZZxNptp0   Probably nothing to gain, but you won't loose much either.   One that old is probablly due for a change unless you need it like I need some old dos computes to program up some old equipment.

mike <ham789@netzero.net>: Feb 10 03:29PM -0800 On 2/10/2018 2:03 PM, Gareth Magennis wrote: > He has a hot air rework tool and he said I might be able to reflow > the chip. Is this something that a rank amateur can likely do? > Eric   I experimented with it on a laptop video chip.   I built a box with a square hole in the top. Put in air baffles to point airflow at the hole. Stuck a variable paint stripper in the side of the box.   Cleaned the area under the chip with repeated applications of simple green, alcohol, water and lots of air. Dried it overnight in a hot box at about 120F. Used liquid flux designed for reflow repair under the chip.   Put thermocouples on the board and spaced it above the hole.   Adjusted the paint stripper to ramp the temperature of the bottom of the board to just below the melting point of solder. Aimed a temperature controlled air flow designed to desolder chips at the unmasked area around the chip on the topside. Heated the top of the chip to above the melting temperature of solder. Used topside thermocouples, but today would probably try a thermal imager. Fixed the intermittent video problem.   Elated with my success, I tried another. I had been using paper towels for insulation under the aluminum foil topside mask. Got careless and set the paper towels on fire. Putting out the fire jostled the board and some chips fell off the backside. EPIC fail!   over the next year... Third try fixed another laptop.   Fourth try didn't help that laptop. Fifth try didn't help that laptop.   Laptops got so cheap at garage sales that reflowing one wasn't worth trying.   YMMV

"Gareth Magennis" <soundserviceleeds@outlook.com>: Feb 11 12:11AM "mike" wrote in message news:p5nv95$70t$1@dont-email.me...   On 2/10/2018 2:03 PM, Gareth Magennis wrote: > He has a hot air rework tool and he said I might be able to reflow > the chip. Is this something that a rank amateur can likely do? > Eric   I experimented with it on a laptop video chip.   I built a box with a square hole in the top. Put in air baffles to point airflow at the hole. Stuck a variable paint stripper in the side of the box.   Cleaned the area under the chip with repeated applications of simple green, alcohol, water and lots of air. Dried it overnight in a hot box at about 120F. Used liquid flux designed for reflow repair under the chip.   Put thermocouples on the board and spaced it above the hole.   Adjusted the paint stripper to ramp the temperature of the bottom of the board to just below the melting point of solder. Aimed a temperature controlled air flow designed to desolder chips at the unmasked area around the chip on the topside. Heated the top of the chip to above the melting temperature of solder. Used topside thermocouples, but today would probably try a thermal imager. Fixed the intermittent video problem.   Elated with my success, I tried another. I had been using paper towels for insulation under the aluminum foil topside mask. Got careless and set the paper towels on fire. Putting out the fire jostled the board and some chips fell off the backside. EPIC fail!   over the next year... Third try fixed another laptop.   Fourth try didn't help that laptop. Fifth try didn't help that laptop.   Laptops got so cheap at garage sales that reflowing one wasn't worth trying.         ****************************       Took me a few attempts on old Mac laptops to realise you can't do this job with a paint stripper.       Gareth.

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