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Hilda Winkler <hildawinkler77@gmail.com>: Nov 18 02:53PM -0800 > *BUT*(!), you said in your first post you were getting a random shutoff condition, and now you said it was getting stuck on the Vizio logo on the screen. That's a different issue altogether, although it's probably too late now because you might have torched the BGA.   > The M550SV not starting at all or getting stuck on the boot logo is generally a corrupted NAND chip on the back side of the board. It's a 48 pin surface mount TSOP1 flash (the only one on that board) and isn't easy to change if you don't have surface mount soldering experience. I used to change them when the TVs were pretty new until the BGAs started acting up as the TVs got older and built up miles.   > Check your connections. If you can get it back to the stuck logo, you can order one of these already programmed from a guy in Texas - I think it's Coppell TV or something close, and change it if you can solder tight pitch smd stuff. If not, keep trolling ebay for a cheap one.     after reheating the BGA chip, i checked the power supply board. and I'm getting zero volts going to the main board on all pins. looks like a short, checked all connections. maybe i could have melted the solder under the chip when reheating and created a short???

"ohg...@gmail.com" <ohger1s@gmail.com>: Nov 19 08:03AM -0800 > > The M550SV not starting at all or getting stuck on the boot logo is generally a corrupted NAND chip on the back side of the board. It's a 48 pin surface mount TSOP1 flash (the only one on that board) and isn't easy to change if you don't have surface mount soldering experience. I used to change them when the TVs were pretty new until the BGAs started acting up as the TVs got older and built up miles.   > > Check your connections. If you can get it back to the stuck logo, you can order one of these already programmed from a guy in Texas - I think it's Coppell TV or something close, and change it if you can solder tight pitch smd stuff. If not, keep trolling ebay for a cheap one.   > after reheating the BGA chip, i checked the power supply board. and I'm getting zero volts going to the main board on all pins. looks like a short, checked all connections. maybe i could have melted the solder under the chip when reheating and created a short???   The power supply when unplugged from the main will output at least one voltage al the time. With just AC applied, check for a standby 5 or 12V (or whatever this uses - could be either). If you see the standby voltage, plug in the main and recheck. If that voltage goes away, something is loading it down on the main. Since the BGA is not powered directly from the power supply, the BGA *shouldn't* be the problem (although who knows for sure?). The BGA is powered from one or more dc buck converters on the main, and those are generally current protected, so if the BGA were to short for instance, the buck converter feeding it would shut down but the rest of the board will have power on it - and I'm speaking generally here on this board. If the standby goes away when you plug in the main, then do a basic dc resistance to ground on the standby line and trace out the short.   If the standby voltage on the power supply stays on when you connect the main, check the ps on command from the main back to the power supply. This should be low when in standby and should go to 2.5 - 5V when the power button is pushed.. If the line goes high, then the rest of the supply should turn on. If the line goes high and only the standby voltage stays on but everything else stays low, check the run lines for dc resistance to ground and trace it out.   You can test the power board on the bench by applying AC and jumping the standby pin to the on command across a resistor. If the standby voltage is 5V, a 270 ohm resistor should be safe. If the standby is 12V, I'd use a resistor and zener to get the voltage down below 5V before applying it to the ps on command line. When you jump the standby to the ps on line, the rest of the voltages should appear if the power supply is good.   If the standby voltage is working but the on command voltage to the power supply stays down when you push the power button, then the BGA could be torched.

Chuck <chuck23@dejanews.net>: Nov 19 10:07AM -0600 On Wed, 18 Nov 2020 14:53:23 -0800 (PST), Hilda Winkler   >> The M550SV not starting at all or getting stuck on the boot logo is generally a corrupted NAND chip on the back side of the board. It's a 48 pin surface mount TSOP1 flash (the only one on that board) and isn't easy to change if you don't have surface mount soldering experience. I used to change them when the TVs were pretty new until the BGAs started acting up as the TVs got older and built up miles.   >> Check your connections. If you can get it back to the stuck logo, you can order one of these already programmed from a guy in Texas - I think it's Coppell TV or something close, and change it if you can solder tight pitch smd stuff. If not, keep trolling ebay for a cheap one.   >after reheating the BGA chip, i checked the power supply board. and I'm getting zero volts going to the main board on all pins. looks like a short, checked all connections. maybe i could have melted the solder under the chip when reheating and created a short???   Very possible. That is what happened when I reflowed a bga chip on my son's X-Box.

Jeff Liebermann <jeffl@cruzio.com>: Nov 18 09:52AM -0800 On Tue, 17 Nov 2020 19:04:35 -0500, OJ Oxford <bestnet@none.com> wrote:   Sorry for the late reply. I've been busy.   >connectors. I was smart before I started in that I opened the door with >a fan aiming output outside. Good thing I did because some of the nylon >got to smelling.   The cable insulation is not nylon. The XT60 connector is nylon. From your description, methinks the wire is a silicone outer jacket.   >ordered some more 60/40.   60/40 will work, but 63/37 is about the same price and is easier to work with. Please make sure it has rosin flux suitable for soldering electronic components. I'm partial to no-clean flux, but the rosin mildly activated (RMA) flux will work if you clean off the residue after soldering. Don't use acid core or RA flux on electronics: <https://blog.gotopac.com/2020/03/24/rosin-flux-soldering-flux-rosin-types-classification/>   >All I have are some 25 watt pencil irons, maybe a 40 watt, and then we >jump to a Weller 100/140 gun and 150/240 Radio Shack gun.   25 watts is too small, 40 watts might work depending on how long you want to wait for the tip to heat and how big a tip you're using. For a 3/16" chisel tip, that could be a long time. However, don't throw these pencil irons away. They're the right size for soldering tiny SMD (surface mount devices) on PCB (printed circuit boards).   >I don't think >either had the right tip. I might be able to use the Weller if I can >find the correct tip (or order one).   I'm not going to day anything nice about soldering guns. I have one that I last used maybe 30 years ago. The basic problems are: 1. No temperature control or regulation. 2. Not enough mass in the tip to maintain temperature. 3. Awkward and clumsy. 4. Copper expansion and contraction causes the nuts to loosen. 5. Tends to burn adjacent components with a big soldering gun tip. 6. Fairly short tip life depending on how it's used.   There are plenty of cheap soldering stations, with temperature control, and an assortment of tips on eBay or Amazon. I can recommend something if you want, but I don't like recommending something I haven't used. I'm still using 60 year old Weller soldering stations. I keep telling myself that I'll buy something better when I run out of parts, but it never seems to happen. Maybe something like this: <https://www.ebay.com/itm/254768162085> 75 watts. Note that it comes with 10 tips. However, I can't tell if any of them are large enough to solder the #12 wire.   >I'll apply flame to the wires and see if anything burns off once I strip >away the outer silicone shell.   You could just try using an ohmmmeter to see if you get conductivity through the surface of any coating.   >This #12 is very fine silvery looking strands and very flexible. It is >of the kind used in RC (radio controlled cars and aircraft) often for >battery connections, etc.   Looks like it's silicon insulation: <https://hobbyking.com/en_us/catalogsearch/result/?q=12%20awg%20wire> <https://www.amazon.com/BNTECHGO-Silicone-Flexible-Strands-Stranded/dp/B01AQU3ST8> 680 strands of 0.08mm tinned copper wire. I use the stuff for 12V power cord on portable 2way radios because it doesn't get stiff. It's NOT waterproof or wicking resistant, so that's not a problem. There's also no coating on the individual strands of wire.   The wire solders very easily. In fact so easily that I have problems with the solder creeping up the cable and making the first cm or so rather stiff. That also begs the question why are you having problems soldering the wire and XT60 connector? As you can see from the HobbyKing.com URL, they supply pre-made cables with XT60 connectors. It should be really easy. My guess is: 1. Bad tip on the soldering gun. 2. Bad soldering gun (not hot enough). 3. Bad solder, wrong solder, no flux, wrong flux, etc. 4. Grease or oil on the connection.   >Because I wasn't able to finish all of the >soldering today, I did put some under some screw terminals and tightened >down onto the wire. The circuit powered on and no problems.   Ok, that works. However, I think you'll find that the screws will chew up the fine wires in the cable. Same problem with crimping. There's an amazing amount of "air" between the wires. If you screw down or crimp something to the wire, it will initially feel tight. However, as you move the cable around, the empty space will fill up with wire strands and loosen the connection. It's worse with a screw, which will cut strands that eventually fall out. Screws and crimps work best with a few strands and heavier gauge wire. For your application, soldering is the only way.   >heating. Replaced with the chassis mount XT60 and now no heating there >BUT I can't figure out how to keep the plug in the chassis when >disconnecting. The whole thing wants to come out.   XT60 panel mounting kit: <https://hobbyking.com/en_us/xt60-panel-mounting-kit.html> There are others. I'm lazy and just glue an L-bracket to both sides of the XT60 connector.   >for my Weller 100/140 gun would be welcome or even a recommended >soldering iron but I want to avoid the temp controlled ones to keep cost >down.   See my comments about flux, solder, and soldering irons.   >electronics hobbyiest for years, but never soldered anything this large. >During my radio days, sometimes a RG8 cable would have to have an end >soldered on, but that was about all with the large stuff.   Coaxial cables are difficult to solder. I use crimp type coax connectors whenever possible: <http://www.learnbydestroying.com/jeffl/antennas/Misc/slides/crimpers.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

OJ Oxford <bestnet@none.com>: Nov 18 05:41PM -0500 On 11/18/20 12:52 PM, Jeff Liebermann wrote:   > Sorry for the late reply. I've been busy.   No problem. I ran out of supplies anyway, so no matter.     > The cable insulation is not nylon. The XT60 connector is nylon. From > your description, methinks the wire is a silicone outer jacket.   No, the type of tip the Weller had was a wide, flat cutting tip. It was really easy to touch the nylon part of the XT60's while trying to solder the wires on. The wire itself does have the silicone jacket, yes.   k, but 63/37 is about the same price and is easier to > mildly activated (RMA) flux will work if you clean off the residue > after soldering. Don't use acid core or RA flux on electronics: > <https://blog.gotopac.com/2020/03/24/rosin-flux-soldering-flux-rosin-types-classification/>   Actually, 63/37 is what I am getting not the other. It does have rosin, but I also ordered some pure rosin flux.     > 4. Copper expansion and contraction causes the nuts to loosen. > 5. Tends to burn adjacent components with a big soldering gun tip. > 6. Fairly short tip life depending on how it's used.   #5 definitely with the nylon part of the XT60's!   > <https://www.ebay.com/itm/254768162085> > 75 watts. Note that it comes with 10 tips. However, I can't tell if > any of them are large enough to solder the #12 wire.   Thanks, I'll take a look.     > You could just try using an ohmmmeter to see if you get conductivity > through the surface of any coating.   Good idea! I will do that if necessary.   > 2. Bad soldering gun (not hot enough). > 3. Bad solder, wrong solder, no flux, wrong flux, etc. > 4. Grease or oil on the connection.   How about makeshift ways of keeping the connectors and wires steady? This was no picnic. I used to have some "helping hands" but of course couldn't find them when I needed them, so ordered some of those too. I really think the solder I was using had little or no flux too. And of course wrong soldering iron tip.     > which will cut strands that eventually fall out. Screws and crimps > work best with a few strands and heavier gauge wire. For your > application, soldering is the only way.   I don't like the wires under the screws. I may have to look for a solderable connector similar to the crimped type:   https://www.remybattery.com/pub/media/catalog/product/cache/57ed5d5337a374626b6116b782f54f51/s/p/spade-connector-yellow.jpg   I'm lazy and just glue an L-bracket to both sides > of the XT60 connector.   Excellent idea! What type of glue will allow metal to nylon bond? I have some leftover JB Weld.     > Coaxial cables are difficult to solder. I use crimp type coax > connectors whenever possible: > <http://www.learnbydestroying.com/jeffl/antennas/Misc/slides/crimpers.html>   I hated soldering on connectors onto RG8! Eventually, I started purchasing cables with connectors already soldered on, plus there was a radio shop not too far away that would do it free if RG8 was purchased from them. Haven't had to solder it in nearly 3 decades though so not concerned.

Ralph Mowery <rmowery28146@earthlink.net>: Nov 18 06:17PM -0500 In article <rp47vg$2o9$1@dont-email.me>, bestnet@none.com says... > radio shop not too far away that would do it free if RG8 was purchased > from them. Haven't had to solder it in nearly 3 decades though so not > concerned.   Soldering the pl259 to coax was not too bad for me once I either filed the chrome plating off the part I wanted to solder, or even better was going to the silver plated type. At that time I was using a Weller 100/140 watt gun. I never did like the BNC or N connectors for putting the coax on. Too much mechanical work   Then the crimp connectors came out and I have been using them for a long period of time. Really handy when putting connectors on where you are a long way from the AC power.   I have gone to crimping all most all wiring that I can for all types of plugs.   YOu mentioned a wide flat blade. That is probably the one ment for cutting plastic and not soldering. I have a few but never used them. Not sure what the tips I use are made of, but they are silver colored instead of the more common copper tips. However they look like the copper ones.   I have not used the connectors like you mentioned. They appear to be similar to other connectors where you solder the wires to. For those I fill up the cup on the connector and tin the wire. I usually cut the insulation of the wire off about twice what I want, tin the wire and then cut to length. Then heat the connector and push the wire in the cup after the solder melts.   I saw a you tube that does something similar,but he has way too much solder on the wire. YOu want just enough to hold the strands together.

Eli the Bearded <*@eli.users.panix.com>: Nov 18 11:35PM Prompted by a response here, some questions I have.   > electronic components. I'm partial to no-clean flux, but the rosin > mildly activated (RMA) flux will work if you clean off the residue > after soldering.   I still have, purchased around 1990, some Archer 64-005 solder. It's 60/40, 0.032" (about 0.8 mm, finer than typical) "rosin core". I'm running out of it, but that's been my go-to electronics solder since I bought it. I have a 23W / 33W swappable pencil soldering iron from the same period (and also Radio Shack). It has served me well, but I have been thinking maybe time for an upgrade. For one thing, I've never really been able to work with silver solder easily.   The advantage of 63/37 is what? Just lower melting point? Anything else? I know it is the "eutectic" point (ratio with lowest possible melting point), but I don't know if that conveys other desirable traits.   > 75 watts. Note that it comes with 10 tips. However, I can't tell if > any of them are large enough to solder the #12 wire.   Maybe it herectical to suggest this, but, I'd consider using a big tip and preheating it with a torch. That is heat the soldering iron tip with a propane torch and then just rely on the heating element in the iron to keep it from cooling too fast.   I remember my grandfather's soldering irons, one of which was completely unpowered and relied on stored heat. (Most of the images for "soldering iron vintage" at ebay are similar designs.)   Are the typical soldering stations one sees (like the link I dropped for the 75 watt one above) suitable for basic SMT work? I know for some SMT you need an oven in order to heat parts unreachable with an iron, but consider the case of clean removing an SMT LED from a board because not everthing needs a power on light. I don't have really fine tips for my current iron, and SMT is not something I've tried.   Elijah ------ has other solder for non-electronics use, such as ballast

Ralph Mowery <rmowery28146@earthlink.net>: Nov 18 08:04PM -0500 In article <eli$2011181834@qaz.wtf>, *@eli.users.panix.com says... > consider the case of clean removing an SMT LED from a board because not > everthing needs a power on light. I don't have really fine tips for my > current iron, and SMT is not something I've tried.   The main advantage of the 63/37 solder is that as it cools it turns from a liquid to a solid. Any other mix will go through what is called a plastic state. If the wires are moved during that time you get what is called a cold solder joint. It will have to be reheated and maybe some more flux added.   For about $ 75 or less you can get a hot air rework station from ebay. This will not hold up for commercial work, but good enough for the hobbiest that may use it once a month. It is a box with a fairly high wattage iron with changable small tips. Reason for high wattage is the tip is so small for smd that it will not hold much heat. There is also a wand that blows hot air out of a small hole about 1/4 inch in diameter. Both are temperature controlled. You can get a life time supply of some .015 solder for about $ 25.   Get an Amscope se400z microscope so you can see the small parts for about $ 200. The smd is really easy to work with if you spend a few dollars and get the tools to woek with. Lots of videos on Youtube to show how.

dplatt@coop.radagast.org (Dave Platt): Nov 18 05:05PM -0800 In article <eli$2011181834@qaz.wtf>, >same period (and also Radio Shack). It has served me well, but I have >been thinking maybe time for an upgrade. For one thing, I've never >really been able to work with silver solder easily.   Years ago I moved up from a cheap non-regulated soldering pencil, to a Weller WTCP-series (with the ferromagnetic-tip switch) and found it quite an improvement. More recently I bought a used Metcal, and find it very worthwhile... fast to heat, doesn't overheat, and the tip temperature recovers quickly.   I still use a propane-fired pen, or one of a couple of Weller soldering irons for some jobs, but the Metcal is my go-to for PCB work.   >The advantage of 63/37 is what? Just lower melting point? Anything else? >I know it is the "eutectic" point (ratio with lowest possible melting >point), but I don't know if that conveys other desirable traits.   The whole eutectic alloy freezes (and melts) at a single temperature, so the molten mass cools to a solid as a whole, rather than going through a "slushy" temperature range (the slush being a mix of solidified crystals and liquid) as 60/40 does. This can (I understand) reduce the risk of a "cold" solder joint where the joint was moved while the solder was solidifying.

Eli the Bearded <*@eli.users.panix.com>: Nov 18 10:22PM >> the connector-doesn't-fit problem. > I thought it was a solved-problem decades ago? > <https://www.amazon.com/dp/B0722J415P>   That, like my decades old universal power supply with two-prong plug-in tips, does not appear to be a good match for (random female) to (random male) matches. That's a good fit IF you already have a power adapter that has the size those are built for or if you are buying an adapter at the same time as the plug set.   My searches didn't find a universal cord set with male and female ends. Maybe I didn't use the right term?   Elijah ------ has far more two prong plugs than cords to use them with

George Gonzalez <grggonzalez3@gmail.com>: Nov 18 12:01PM -0800 Hi all, I just got two LECroy 6050A oscilloscopes. Both work fine but are missing a few knobs. I cannot find a service manual to look up the part numbers and even the LeCroy web site is kinda mum about parts and service.   Any ideas?   Thanks,   AG0I

John Robertson <spam@flippers.com>: Nov 18 12:20PM -0800 On 2020/11/18 12:01 p.m., George Gonzalez wrote:   > Any ideas?   > Thanks,   > AG0I   https://www.sphere.bc.ca/ has lots of parts for test gear...   Sometime I need to visit that shop!   John :-#)#

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