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alonerasool@gmail.com: Jun 09 03:42AM -0700 Hi there I'm repairing a variable smps based on SG3525 IC. the IC gets too hot and finally it burns away. what's the problem?

jurb6006@gmail.com: Jun 09 04:33AM -0700 > Hi there > I'm repairing a variable smps based on SG3525 IC. the IC gets too hot and finally it burns away. what's the problem?   That is like way too much not enough information.   Is it used to drive a transformer directly or transistors ? If directly, what about the load on the transformer, have you checked the rectifiers on the secondary ?   You have to give some fucking information to get help on shit like this. Does the thing, whatever it is, work but then it pops ? Or just fry out and not work ?   Get more info out here, and actually the duty cycle of the waveform it is putting out. Get a Dropbox account and use the \public directory for pics like this. When you try to use their picture thing it gets all fucked up.   And what is the make and model of this thing ? Unless it is some homebrew custom thing...   If you are unable to supply this information you have no business trying to fix the thing. If you have changed that IC fifty times you have no business trying to fix that thing.   When I ask for help here I got voltage readings, waveforms and all kinds of tricks I did to find out this and that. Sometimes it works ad sometimes nobody knows. You come in here with a post like that most people think you are a total noob and don't know shit.   Now it is up to you to prove otherwise. We can't read your mind or your scope, and you better have one. Of each.

N_Cook <diverse@tcp.co.uk>: Jun 09 12:53PM +0100 > Hi there > I'm repairing a variable smps based on SG3525 IC. the IC gets too hot and finally it burns away. what's the problem?   What frequency? what should it be?

Micky <NONONObobbyburns1111@gmail.com>: Jun 08 03:58PM -0400 [Default] On Wed, 8 Jun 2016 09:43:45 -0400, in microsoft.public.windowsxp.general Wolf K <wolfmac@sympatico.ca> wrote:   >> on. I ended up unplugging it from the adapter at least 10 times >> before it finally started working. And now it's been fine for hours.   >Avoid the problem: buy an uninterrupted power supply.   I have one, but I didn't think to connect the router to it. Thanks

Micky <NONONObobbyburns1111@gmail.com>: Jun 08 04:03PM -0400 [Default] On Wed, 8 Jun 2016 11:43:34 -0500, in microsoft.public.windowsxp.general Mark Lloyd <not@mail.invalid> wrote:     >BTW, I have seldom (if ever) benefited from reporting a power outage. >The system is usually busy from others reporting outages. However, I >still liked checking the map that shows outages.   I don't report them because I know there are others more impatient than I. I just sit in the dark. Plus these days, I wonder if they self-report?   I think night before last was just for a moment. I have a UPS on my DVDR, but it doesn't work as well as I'd hoped for, and iirc even with the UPS, the DVDR forgets what shows to record if the outage is more than a few moments. (testing would be very inconvenient.) Or I could compare with my analog clocks.

"Ian Field" <gangprobing.alien@ntlworld.com>: Jun 08 10:13PM +0100 "Micky" <NONONObobbyburns1111@gmail.com> wrote in message news:ojoelb93k3cdju7bep4hbepf7l9um5movb@4ax.com... > for my router failing after a power outage. Apparently it's not a > power surge but just normal unplugging and replugging that is bad for > many things (especially maybe if they can cool off in between).   Its fairly common for items with an SMPSU to have an inrush limiting NTC thermistor, these reduce in resistance when current flow heats them up - they take a few minutes to cool back to room temperature and return to the higher resistance.   They're mainly to limit the charging surge for the reservoir capacitor - some items don't have the NTC device, but don't seem to be conspicuously any less reliable.   After a certain manufacture date; anything over 50W had to have a PFC front end - basically a switch mode regulator that preceeds the reservoir capacitor - soft start is easier and cheaper to do electronically than include the NTC device.

Micky <NONONObobbyburns1111@gmail.com>: Jun 08 07:05PM -0400 [Default] On Wed, 8 Jun 2016 22:13:39 +0100, in microsoft.public.windowsxp.general "Ian Field" >end - basically a switch mode regulator that preceeds the reservoir >capacitor - soft start is easier and cheaper to do electronically than >include the NTC device.   Well this thing is pretty old. 8 years at least but I can't remember where I bought it. Maybe it was used. D-link DI-524

John McGaw <Nobody@Nowh.ere>: Jun 08 08:10PM -0400 On 6/7/2016 8:17 PM, Micky wrote: > plugged it in 3 times, ALL the lights on the router went on and stayed > on. I ended up unplugging it from the adapter at least 10 times > before it finally started working. And now it's been fine for hours.   It would seem that the logical thing would be to simply buy a new router from a good maker. If the router uses a 12V supply and your area has bad power problems something like a Belkin BU3DC001-12V instead of a 'normal' wall-wart supply might be advisable too if the plug is fully compatible. I use the Belkin on my AT&T modem (it came with one) and another on my main switch in the equipment room (I had a spare one just sitting there) while each of the computers has their own 1200VA AC UPS supplying it and any important ancillary network equipment, etc, in their vicinity. I have five of these AC UPS units. The power in my area really sucks big time and I eventually learned my lesson...   But I never did see any symptoms such as you describe -- everything reset fine after being powered off for a few seconds or when the reset button was pressed (in the old days where there were actual reset buttons on small network equipment).

Jeff Liebermann <jeffl@cruzio.com>: Jun 08 07:32PM -0700 On Wed, 08 Jun 2016 19:05:53 -0400, Micky   >Well this thing is pretty old. 8 years at least but I can't remember >where I bought it. Maybe it was used. D-link DI-524   Garbage. I had nothing but problems with that vintage D-Link hardware due to line glitches. The stock 5V 2.5A JTA0302B power supply is a known headache. They tend to last about 3-5 years before the capacitors bulge. If you put a scope on the PS line, you'll find it full of switching trash. If you're good at brain surgery and working in tight spaces, you can possibly fix it.   This is unusual, but cute: <https://www.youtube.com/watch?v=oMVyFy_pb7E> (1:41)   Look through the Linksys refurbished collection for a cheap replacement: <http://stores.ebay.com/Linksys-Official-Store?_dmd=2&_nkw=refurbished>   -- 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

Micky <NONONObobbyburns1111@gmail.com>: Jun 09 12:16AM -0400 On Wed, 08 Jun 2016 19:32:39 -0700, Jeff Liebermann <jeffl@cruzio.com> wrote:   >due to line glitches. The stock 5V 2.5A JTA0302B power supply is a >known headache. They tend to last about 3-5 years before the >capacitors bulge.   Yeah, now I r emember that we talked about capacitors (on electonics repair) the last time, and I cracked it open and looked, but I didnt' seen any that looked swollen. Maybe I just don't know how to look.   And my experience is consistent with yours, 2 bad ones in 8 years. Last time, after the new power supply came via Ebay, it dawned on me that I'd bought a spare at a hamfest, but I went to look at it, and it had no wifi, only routing, and the power supply wasn't with it. But then a few months later, I found a brand new, still wrapped in cellophane, same thing as I'm using. I'd forgotten I had both. So I know where to get a 3rd powersupply and if it blows, I'll go back to the Ambico Universal Digital Camera AC Adaptor, 2100mA, with 4 different tips** and voltages from 3 to 7 volts. I paid $9 for it 20 years ago for just this sort of situation.   **tubular tips, none of which would fit any digital camera made these days, because they are all USB, aren't they? Even many of the brands of camera they list don't make cameras anymore, afaik: Hewlitt Packard, Vivitar, Kodak, Minolta, Epson. Epson?   > If you put a scope on the PS line, you'll find it >full of switching trash. If you're good at brain surgery and working >in tight spaces, you can possibly fix it.   I'm working on it, but when I get good at brain surgery, I plan to be a brain surgeon.

"Ron D." <Ron.Dozier@gmail.com>: Jun 08 10:25PM -0700 Quote from someone   But I never did see any symptoms such as you describe -- everything reset fine after being powered off for a few seconds or when the reset button was pressed (in the old days where there were actual reset buttons on small network equipment).   Seen those sort of symptoms all of the time. Power glitching is a good reason for them. If there's no backup batteries within the device, pull the adapter and short the input to the router for at least 39 seconds. I've resurrected a number of things this way. The last device was a wireless mouse. Did the "short trick" overnight and it worked. Usually 30s to 1 minute usually works.   The method has a good reason why it works. I also resurrected a automobile clock that died shortly after a jump start. A bit harder and it was never removed from the dash.

whit3rd <whit3rd@gmail.com>: Jun 08 11:25AM -0700 On Tuesday, June 7, 2016 at 5:10:12 PM UTC-7, Micky wrote:   > [about a suspect capacitor] I'll replace it. Easy enough.   > 16volts 1000uF, I suppose the bag of caps in the basement for the last > 30 years are too old to use???? If so I'll buy a new one.   If you have a suitable (15VDC, but 10V or 24V would work, too) power source, clip it onto a few old capacitors overnight. The next morning, unclip 'em, wait a few seconds, and any that make your voltmeter jump, are good to use.   Even if an old electrolytic doesn't meet its original specs after storage, it DOES heal if you give it a voltage bias. I've done it in minutes with overvoltage and a heat gun, but overnight at room temperature is good enough. The capacitor needs applied voltage and time to re-form its oxide layer.

Micky <NONONObobbyburns1111@gmail.com>: Jun 08 07:00PM -0400 On Wed, 8 Jun 2016 11:25:48 -0700 (PDT), whit3rd <whit3rd@gmail.com> wrote:     >> 16volts 1000uF, I suppose the bag of caps in the basement for the last >> 30 years are too old to use???? If so I'll buy a new one.   >If you have a suitable (15VDC, but 10V or 24V would work, too) power source,   The adapter for my laptop is 17v or thereabouts. I presume the negative side goes to the negative on the capacitor?   >heal if you give it a voltage bias. I've done it in minutes with overvoltage >and a heat gun, but overnight at room temperature is good enough. The capacitor needs applied >voltage and time to re-form its oxide layer.   All very good, thank you. a) one cap is expensive by mail, plus the postage. (Time is not much of a factor anymore. Mail order is a lot faster than 50 years ago.) b) There was no point to saving these capacitors if I can't use them anymore. c) There is only one store in Baltimore that woudl have this and they fairly far away and expensive. Hmm. Radio Shack is still in business, sort of. (They used to have the best webpage, that said everything a specific store had and how many of them. When I bought one, the number on the web went down.) Well they sell the part but I've waited 10 minutes and "Find in Store" never loads.   But I'll start with what I already have.

"Ian Field" <gangprobing.alien@ntlworld.com>: Jun 08 08:02PM +0100 "Johann Klammer" <klammerj@NOSPAM.a1.net> wrote in message news:nj8ua1$a95$1@gioia.aioe.org...   >> Thanks for any help. > <http://formfactors.org/developer/specs/Power_Supply_Design_Guide_Desktop_Platform_Rev_1_2.pdf>(page23) > <https://en.wikipedia.org/wiki/ATX>   Thanks - the first link gave a 404, the Wiki page had the info.

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