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Dead power supplies — Parallax Forums

Dead power supplies

GordonMcCombGordonMcComb Posts: 3,366
edited 2015-06-23 00:58 in General Discussion
Everyone who woke up to a dead power supply on their computer, raise your hand.

(hand raised)

Comments

  • Heater.Heater. Posts: 21,230
    edited 2015-06-20 09:53
    Amazingly I don't recall that I have. Hard drives, yes. Floppies certainly. Graphics cards, yes. Fans, yes. All kind of other stuff, yes. I've even tried killing PC power supplies by re-purposing them but they seem to protect themselves very well.
  • GadgetmanGadgetman Posts: 2,436
    edited 2015-06-20 12:45
    I've only lost one Computer PSU, and that was the external PSU for my old Mac Mini. I'm just assuming that the thunderstorm that night might have had something to do with it...
  • GordonMcCombGordonMcComb Posts: 3,366
    edited 2015-06-20 12:53
    Second one for me. Last one was about five years ago. Both times it was from an HP computer -- a brand I no longer purchase, thanks very much.

    No storm last night, so it was just one of those things. Fortunately I had an old frankenbox that I've been taking other parts from, so I already had the replacement.
  • Hal AlbachHal Albach Posts: 747
    edited 2015-06-20 13:08
    In my earlier life when I worked for Fujitsu We replaced a ton of Dell Tower power supplies which would work fine as long as the computer was never shut off. Turn them off and you had a 50-50 chance of restoring power. Turns out they failed because they had a small resistor fail in them that supplied the standby voltage to the motherboard which was used for the power on/off pushbutton circuit. I have since learned that grounding the only green wire in the 24-pin harness will turn on the power supply - provided none of its innards are fried or spilled all over the place and there is some type of load on the output.. The lone violet wire in that harness carries the aforementioned standby voltage.

    As far as actually digging deep into a dead SMPS to locate a faulty component, no, I've never done that. I figured that everything in there is in some way dependant on the other stuff in there, so when a particular part goes Tango Uniform, other parts join in on the fun.
  • GordonMcCombGordonMcComb Posts: 3,366
    edited 2015-06-20 14:16
    Oh, great. I also have a Dell tower! Hopefully, it's a later model than the ones you worked on. It's circa 2010. So far it's been reliable (knock on wood).
  • Hal AlbachHal Albach Posts: 747
    edited 2015-06-20 14:33
    Oh dear..... If I might, I would suggest looking into getting a spare power supply, a good one like Corsair, and keep it on hand. Maybe even bump the wattage up a little for those inevitable upgrades, like a video board that requires its own power sub-station. This way you will have the unit on hand should the one in the tower go kaput. Beats waiting several days for another one to arrive while the system is down.
  • GordonMcCombGordonMcComb Posts: 3,366
    edited 2015-06-20 14:55
    So are T5500 Xeon's in the timeframe of the ones you were working on? I know earlier Dell's from the early-mid 2000s had a number of PS problems.

    I got it second-hand, and it looked to be pretty-well used, so it's survived so far! (knocking on wood yet again). I might take your suggestion and get a spare PS now, though I'm also in the market for a new machine with more modern architecture (PCIe 3.x, for example). Currently I don't have anything extra running in it -- just a single Xeon, and the nVidia graphics card is original (and quite underwhelming).
  • kwinnkwinn Posts: 8,697
    edited 2015-06-20 15:05
    Hal Albach wrote: »
    ............................................


    As far as actually digging deep into a dead SMPS to locate a faulty component, no, I've never done that. I figured that everything in there is in some way dependant on the other stuff in there, so when a particular part goes Tango Uniform, other parts join in on the fun.

    Most common problem with switching supplies is the filter capacitors. The high current pulses will eventually cook even the best low esr capacitors eventually. Look for swelling or signs of overheating. When switchers were several hundreds of dollars I would replace all the front end electrolytics and that would get them working. With a $35.00 PC switcher the caps cost more than the supply so it's a new one.
  • Phil Pilgrim (PhiPi)Phil Pilgrim (PhiPi) Posts: 23,514
    edited 2015-06-20 15:27
    More than once. But I favor compact-format desktops. The power supplies are physically smaller, and the cases get a little warmer.

    -Phil
  • Hal AlbachHal Albach Posts: 747
    edited 2015-06-20 15:42
    I can't readily recall the actual model numbers but that T5500 does tickle the few memory cells I have left. When I retired from Fujitsu 6 years ago we were still having occasional Dell PS failures. The failures would include a wide range of tower models including one that was supposed to be "very reliable" and included hot swap raid and redundant hot swap power supplies which slid into the server like a tray and had heavy blade contacts in the rear.

    I'm with you there, Kwinn, like a lot of things, PC power supplies are not so economically repaired anymore. But hey! They are a good source of high power mosfets and various configurations of high current Schottky (sp?) diodes, inductors, heat sinks, not to mention a good supply of heavy duty wire.
  • Cluso99Cluso99 Posts: 18,069
    edited 2015-06-20 15:48
    Touch wood!

    Almost all my PC failures have been caused by Microcrap's Windoze and associated development software :(
    This required re-installing Windoze regularly - used to be every 3 months. Thankfully this was greatly reduced with Windoze 97SE. It became rare with Windoze XP.

    Next on the list of failures were viruses even though I was extremely careful not to open any email not from a trusted source and contained some explicit wording - I mean not a generic message. I didn't take floppies from any unknown source. Every virus I got could not be found by the virus software of the day. Usually the virus software took another 3 months to detect the virus I had. So the result was a complete software install on each occasion. Had about 5 of these, which wasn't bad I suppose considering I used PC's commercially on a daily basis.

    Never had a failed power supply although recently I replaced a friend's failed power supply (using an old retired PC's power supply I had on hand). No data was lost. My mother had a fried motherboard once and I was able to rescue the HDD. Had a few fried color monitors fail in the 90's - I was using large monitors and the cheaper models tended to not last as long but I usually was ready for an upgrade in resolution/size when they failed.

    Laptops originally were no reliable most likely due to not being able to dissipate the heat properly. But that changed more than 10 years ago.
    I have and use regularly 4 Acer laptops, 2 from 1996 and 2 from 1997. I have replace one power brick, and one power connector on the motherboard (actually a little pcb) - cost for the connector was an expensive $6 on eBay.
    My brother bought a Lenovo and it died after about 3 years - dead motherboard - recovered data from HDD.
    I bought a Compaq in 2010 and died in 2014. HDD removed and put into external HDD USB box and data recovered.
    Bought an Acer in 2015 and going strong.
    BTW laptop batteries are a different matter. All 4 original Acer batteries have almost no life (5-10 mins max) but since I almost always have external power available, it's not a problem.
    Needless to say, I like Acer Laptops.
  • idbruceidbruce Posts: 6,197
    edited 2015-06-20 17:44
    Over the years, I have had numerous power supplies fail on me, and as Phil indicates ....
    More than once. But I favor compact-format desktops.

    Not that I personally favor compacts, but the Dell GX280 was perfect for fitting under the TV for Netflix, however the power supplies in these SFF computers go quickly. I brought my latest one back to life by simply recapping all the capacitors.
  • Martin_HMartin_H Posts: 4,051
    edited 2015-06-20 18:00
    We have at least one computer for each person in our house hold. I think everything that can go wrong with computers has gone wrong at least once. The desktops are all Microcenter house brand with interchangeable parts, so that helps. But the laptops are not as easy to service. I feel like the IT department.
  • LoopyBytelooseLoopyByteloose Posts: 12,537
    edited 2015-06-21 02:53
    So far (over all the years of computer use), I have only had one 2 amp 5VDC wallwart fail. That was to my Wifi router which I dearly love, and seemed to be a lightnigh strike. And one wall-wart for my Asus EEEpc.

    I switched the router over from the wall wart to a 3amp 5VDC switcher that was intended for industrial use. It seems to have more protection from power line problems.

    Desktops, laptops, and such are all fine so far.

    +++++++++
    I have had one S.M.A.R.T hard disk warning and swapped out the hard disk that seem to work fine before actual failure. And I have had DRAM fail.
  • xanaduxanadu Posts: 3,347
    edited 2015-06-21 09:34
  • ratronicratronic Posts: 1,451
    edited 2015-06-21 09:55
    A few years back I had a 250W P.S. that didn't wake up when I did.
  • CuriousOneCuriousOne Posts: 931
    edited 2015-06-21 10:40
    I can't remember any PC PSU falling on me since 1994. However, during these times, I've replaced at least 5 PSU's in family and friends computers. My wife's DELL laptops genuine DELL power supply failed twice. So after 2nd failure, I've bought 95W adapter, instead of 65W one (the reccomended one), goes strong for latest 2 years.
  • Heater.Heater. Posts: 21,230
    edited 2015-06-21 10:59
    Wow, an ED-209 barbecue. Brilliant!
  • abecedarianabecedarian Posts: 312
    edited 2015-06-21 12:09
    xanadu wrote: »
    I'd buy that for a dollar!
  • potatoheadpotatohead Posts: 10,261
    edited 2015-06-21 20:38
    Only on dead supply ever. It was due to heat which accumulated as the machine tried to vacuum the floor.

    I no longer put machines on floors.
  • Heater.Heater. Posts: 21,230
    edited 2015-06-22 02:13
    potatohead,
    I no longer put machines on floors.
    I once had to work in a basement office. All the PC's were on the floor. For some reason I started to worry that if there was a flood they would all be drowned. When I mentioned this concern some little tables soon arrived and all the machines were jacked up off the floor. Also a flood alarm was installed.

    Oddly enough a few months later there was a torrential down pour of summer rain on a Friday night and that basement flooded two feet deep in horrid dirty water which left a inch of mud on the floor when it drained away. Nobody knew about any of this until they arrived back at work on the following Monday. Murphy had his say in all this, the cleaning lady had previously picked the water detector up from the floor and neatly coiled up it's cable so it hung halfway down the wall and she could clean the floor. There was no flood alarm.

    Anyway the PCs were still humming away on their little tables.

    And the moral of this fascinating tale? Never work in a basement, never put PC's on the floor, never allow a cleaning lady into your office, or something like that.
  • LoopyBytelooseLoopyByteloose Posts: 12,537
    edited 2015-06-22 08:15
    I strongly suspect the reason I haven't have power supply failures on my big PCs is that I cleaned the inside regularly with a clean paint brush and a vacumn.

    That layer of dust one allows to build up is thermal insulation.

    +++++++++
    I don't dread basements so much as basements that require sump pumps. But considering how much torrential rain flooding I have seen here in Taiwan, maybe I should revise my thinking.... multi-story under ground parking lots pretty much fill to the brim from runoff on the wrong street.

    And then everyone sells their car for a pitance, and buys a new one. I shocked a friend by explaining how little it actually costs to revive a sunken car. Mostly you just have to replace the interior --- carpet, headliner, and seat covers; and change the oil and battery.
  • GordonMcCombGordonMcComb Posts: 3,366
    edited 2015-06-22 08:58
    This most recent failure -- like the previous one -- was pretty unstunning. Computer just wouldn't restart from sleep. The PS appeared to have passed to the other side overnight.

    My most remarkable experience with a failed power supply was in 1987 or so, with an original 128K Macintosh. I was a contributing editor to Macworld at the time, doing various product reviews, and one was for a 512K addon pack that literally hanged off the back of the machine. The added RAM pack was the size of a thick textbook.

    Well, the thing is, Apple designed the PS for these Macs for its hardware; no more, no less. There was no expanding a Mac back then (yeah, like that's changed), and so it shouldn't have been a surprise that the additional RAM was a strain on the power supply. I was using the machine one day when yellow and white smoke *billowed* out the back. The little black and white screen slowly shrank from one side, until the picture was completely gone. Talk about letting the smoke out!

    I toyed with the idea of fixing the PS, as the component(s) that went looked to be the big caps. But it was an excuse to get a new Mac. Twenty-five hundred freakin' dollars later I had a shining new (still monochrome) Macintosh. Woowee! I was living the high life back then.
  • Chris SavageChris Savage Parallax Engineering Posts: 14,406
    edited 2015-06-22 10:56
    At my computer shop I had a customer who brought in a PC that smelled very bad. Like fried PCB. Turns out there was a storm and we had a few brownouts and this power supply failed in such a way that it sent line voltage to the outputs and blew everything! The only salvageable thing was the case itself. During the failure the CD tray had managed to open which gave a certain visually irony to what happened.
  • LoopyBytelooseLoopyByteloose Posts: 12,537
    edited 2015-06-23 00:58
    My first PC that I bought in Taiwan was second hand. The first thing to go was actually the case.

    It rusted out due to air pollution, tropical temperatures, and high humidity. Having a local steel industry provided high acidity in the air, and lots of graphite dust. Just looking inside the chassis was nightmarish, and I quickly was inspired to replace it with something better before it went up in smoke.

    After that, I got into the annual cleaning mode and was able to afford air conditiion that brings down the ambient temperature and the humidity. Industrialized tropical climates are not computer friendly.
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