UPS will not power computer during power failure

Collapse
X
 
  • Time
  • Show
Clear All
new posts

  • pentium
    replied
    Re: UPS will not power computer during power failure

    I have a SmartUPS 700 and I don't even bother hooking more than the system and router to it because it's already at 3/4 load. If the power goes out, just remotely login and gracefully shutdown in ten minutes or less or else the system powers itself down regardless.

    Leave a comment:


  • Longbow
    replied
    Re: UPS will not power computer during power failure

    Originally posted by KeriJane
    The metal APC SUA SmartUPS series produce a sine wave output which is what our PSUs are designed for.
    Off hand, I'm not aware of any supplies that specify that a square wave input is OK.
    They're big, very heavy and expensive but get the job done.
    Yes, just think about the size of the parts necessary to act as low pass filters at 60 Hz. As the current requirements go up, so does the wire size and the core size, etc. There is a good reason why they are so expensive. I don't know why anyone would risk feeding computer equipment with square waves because that is just asking for trouble.

    Leave a comment:


  • kc8adu
    replied
    Re: UPS will not power computer during power failure

    many good small ones do indeed test their batts.one of my old apc units kept alarming for a bad battery.being a big external i load tested it.was fine.measured at the ups with the inverter running no load.10.8v!at battery 12.9.
    i had a bad solder joint in a powerpole lug.reheated with a torch and problem solved.
    my old weller gun couldnt get things hot enough to do the job.and you cant see down into the lug!passed the pull test.but must have been only a few strands of that #4 wire making it.

    Leave a comment:


  • severach
    replied
    Re: UPS will not power computer during power failure

    Originally posted by lti
    This UPS isn't intelligent enough to determine that the battery is dead if it won't power the computer at all.
    I haven't found any small ones that are. Seems like an extra 2 penny chip would solve this problem. They just shut down once they try to power from a dead battery even though power continues to be available at the plug.

    I got rid of all my UPS for this reason. I found that original batteries last about 5 years. El-cheapo replacements last about 3. Because they can't detect, lock out, and alarm bad batteries and they switch to battery any time a small voltage drop comes across the line, a UPS with a battery at the end of its life causes constant computer outages. To prevent failure I decided that I would need to replace the batteries every half time interval or 1.5 years. 1.5 years times a few dollars is... too many dollars per year on top of what I already pay the Power Company for outages.

    How terrible must a designer be to design a UPS that causes the very problem it's trying to solve? How dumb must a customer be to buy a product that causes... and this time that customer is me!

    To me a UPS is useless without dual power supplies. One runs from the UPS and one runs from the wall, on a different circuit for a high reliability installation. That way the UPS can go off as many times as it wants so long as I catch it by the next real power outage.

    Leave a comment:


  • kc8adu
    replied
    Re: UPS will not power computer during power failure

    tested a apc xs1300 today.
    hooked up some wheelchair batts and loaded it up close to max.ran cool and no timer!
    its an all plastic design though.one of my business partners adopted it and 2 100ah high rate ups batts.

    Leave a comment:


  • KeriJane
    replied
    Re: UPS will not power computer during power failure

    I studied UPS's a few years ago for this beastie Mac Pro.

    Here's my findings, for what it's worth:

    The metal APC SUA SmartUPS series produce a sine wave output which is what our PSUs are designed for. They're big, very heavy and expensive but get the job done.

    Practically everything else out there produces either a square wave or a "simulated sine wave" (stepped square wave) which is not as friendly to our PSUs. Short term use like that for an orderly shutdown should be fine but extended operation could be hard on the PSUs of connected equipment.

    Here's where I ran into trouble....

    When most computers start, including the Mac Pro, there is a brief period while things are energized in sequence. This spreads the startup current over time and reduces the sudden demand all at once that would otherwise occur.

    The 1st-gen Mac Pro has a charming characteristic: A cold boot is sequenced but waking from Sleep is not! This absolutely causes anything less than a very hefty UPS to overload.

    Why is startup important for a UPS? Because if you connect the UPS to a USB port, it will wake the computer from sleep when power goes out and cause an overload.

    It seems that the minimum UPS for the MP's 1kw power supply is the SUA1500 which works out nicely.
    The same could hold true for any system with a 1kw PSU though.... the UPS has to handle a wake from sleep which can be as much or more than a boot up. Unless of course the system never sleeps.


    Oh well... an expensive Mac Pro needed an expensive UPS. No big deal, but it took a while to figure that out.

    I look at it like this: the UPS will be around a very long time. Might as well get a great one rather than waste time and money with a cheap one..

    Leave a comment:


  • lti
    replied
    Re: UPS will not power computer during power failure

    The software finally told me that the battery needs to be replaced because it is over three years old. This UPS isn't intelligent enough to determine that the battery is dead if it won't power the computer at all.

    Originally posted by Longbow
    The purpose of a UPS is to give the system enough time to shut down properly.
    That is what this UPS is used for. The original battery works for this purpose.

    Leave a comment:


  • RJARRRPCGP
    replied
    Re: UPS will not power computer during power failure

    Originally posted by kc8adu
    +1
    if its the cs (cheap shit) plastic thing its junk.even a recall due to fire.
    Yep, the plastic ones are cheap! On one day on May, 26, 2002, IIRC, my Phillips 107S wasn't even getting power so I unplugged it then plugged it back in and when I plugged it back in, got a blue spark with a pop! Then all the battery outlets were dead permanently!

    The plug blades are a hazard, one of them dislocate and causes an arc that kills the backup outlet circuit.

    Leave a comment:


  • dood
    replied
    Re: UPS will not power computer during power failure

    Originally posted by Longbow
    You are misinformed. The purpose of a UPS is to give the system enough time to shut down properly. It is not designed to operate the equipment during a power failure. As such, a large system may require a large number of batteries to supply adequate power for a short time while it shuts down.
    Or, in datacenters, to run the equipment until the generator starts up and has stabilized enough to take load.

    Leave a comment:


  • Longbow
    replied
    Re: UPS will not power computer during power failure

    You are misinformed. The purpose of a UPS is to give the system enough time to shut down properly. It is not designed to operate the equipment during a power failure. As such, a large system may require a large number of batteries to supply adequate power for a short time while it shuts down.

    Leave a comment:


  • ThePCDoctor
    replied
    Re: UPS will not power computer during power failure

    It would seem like some brands of UPS are sensitive to the battery being used with them.
    I tried the lead acid battery trick on a 'Cyber Power' ups and it was a NO-GO.

    A friend got a very large APC UPS that required 24vdc, lead-acid batteries to power it.
    Originally it had four large 6v batteries, but they had died.
    He connected two 8D truck batteries to that USP and it ran just fine.

    The APC Brand UPS's seem to be less sensitive to what battery is connected to them, than other brands. That gives the user a lot more flexibility as to what battery to use.

    Cheers Mates!

    Leave a comment:


  • kc8adu
    replied
    Re: UPS will not power computer during power failure

    the es will not take the external trick.heatsinks too small and timer in firmware.
    the best batts i have used were the enersys/yuasa.
    check for recall and if not on the list buy a quality battery.
    or look for a free/cheap older apc.like a back-ups or smart-ups 650.still 12v.a lighter socket and a 15a breaker so you can charge phones,ect in a pinch.runtime limited by how much lead you want to hook up.

    Leave a comment:


  • joshnz
    replied
    Re: UPS will not power computer during power failure

    A month or 2 ago there was a switch over/or shot in the towns supply (around 2 secs of bad power) my ups failed to keep my system up, a new battery fixed it.

    Leave a comment:


  • ThePCDoctor
    replied
    Re: UPS will not power computer during power failure

    Several years ago, I was given an old 600VA, APC UPS because the original batteries were leaking out on the customer's carpet. I took out the old batteries and cleaned up the mess in the case and connected an extra car battery to it just to see if it would actually work. It did.
    Here is my current battery for that USP:


    These are the cheapest batteries I could buy at Wal-Mart and they come with a great warranty. The UPS keeps them fully charged with NO problem. I connected the batteries to the UPS with 12ga wire, with a 30A fuse, in line.

    On the last test I performed on this UPS it ran for seven hours, before it even started a slow BEEP to tell me the batteries were getting low. I figured that was good enough and restored line power, to end the test.
    This old UPS backs up my 27" TV, Cable box, DVD Recorder, one table lamp and a small personal fan, for a little comfort during extended power outages.
    If the cable goes out, I also have the outside antenna amplifier and digital decoder box connected to the UPS, so I can still get Weather Reports.

    So, connect a 12v battery to that old UPS and see if it still works.

    Good Luck,
    The Doctor

    Leave a comment:


  • larrymoencurly
    replied
    Re: UPS will not power computer during power failure

    Several months ago, I found that a couple of 4-5-year-old batteries that always passed their backup's built-in test couldn't power their computers for more than 30-60 seconds.

    BTW, the Friday Fry's ad features a 550VA (330W?) APC backup for $35, after rebate.

    Leave a comment:


  • lti
    replied
    Re: UPS will not power computer during power failure

    This is a Back-UPS ES500. It is a cheap home model. I don't need anything better for an old Dell Dimension 4550.

    I think the battery is a Werker brand. It was a very cheap battery. The genuine APC batteries are also cheap Chinese batteries with an APC label applied over the original markings. I don't think the $30 generic batteries are much worse than a genuine APC battery that costs twice as much. Obviously, the $25 Werker batteries suck.

    Leave a comment:


  • kc8adu
    replied
    Re: UPS will not power computer during power failure

    +1
    i pull out plenty of year old werker and xtreme+ from ups units.
    junk.the only good agm/gel they stock are the us made ones with the bolt head looking caps.those are east penn/deka.and of course the oddesy and optima.
    is yours the old metal cased apc?
    if so the external battery trick is good.if its the cs (cheap shit) plastic thing its junk.even a recall due to fire.
    Originally posted by shovenose
    Batteries Plus has sold me many crappy products. I don't go there anymore. So that's probably your issue. I would go for a legit APC battery if I were you.

    Leave a comment:


  • Evil Lurker
    replied
    Re: UPS will not power computer during power failure

    I say screw both of them and get a big honking deep cycle marine battery and mount it outside the chassis with some extension cables.

    Leave a comment:


  • shovenose
    replied
    Re: UPS will not power computer during power failure

    Batteries Plus has sold me many crappy products. I don't go there anymore. So that's probably your issue. I would go for a legit APC battery if I were you.

    Leave a comment:


  • lti
    replied
    Re: UPS will not power computer during power failure

    The battery is due for replacement. The battery was replaced three years ago. There are no alerts saying that the battery is bad. The UPS is about six years old and has worked fine with this computer until now. I wanted to see if there is something wrong with the UPS itself instead of just having a bad battery.

    I am using a cheap generic battery from Batteries Plus. The original APC battery still had some life left in it after three years, but it is also more expensive. I was hoping that it would only need a new battery.

    Leave a comment:

Related Topics

Collapse

  • Tynan Dill
    Vizio e601i-A3 - Has Sound and Display, But No Backlight - Bad Power Supply Board or Bad LED Bulbs ?
    by Tynan Dill
    I was given this TV from my great uncle. He said it just wouldn't turn on one day out of nowhere, replaced the TV, and gave it to me to possibly fix and use for myself.

    Upon bringing it home and plugging it up, it showed a standby light.

    I powered it on and without a flashlight, the display showed the "V" but the lighting is very dim, but visible.

    The screen seems to blackout and stay black, but with a flashlight I can see the display.

    With my Playstation 4 connected via HDMI, and running a game I can hear sound.

    Assuming...
    11-22-2024, 01:46 PM
  • PantherDave
    Microsoft Surface Pro (5th gen) model 1796 - no power
    by PantherDave
    Hi all!

    I'm trying to troubleshoot a Microsoft Surface Pro (5th gen) model 1796 that won't power on. Motherboard model is M1007506-015. My priority is retrieving data, but the SSD is integrated so it looks like if I can't repair it it'll need to go to a data recovery company. I've done a little basic board repair before, but nothing this advanced until now. So please forgive my ignorance in advance. 😅

    I found the boardview for this laptop in the forums here, and am able to open it on my PC with FlexBV.
    https://www.badcaps.net/forum/troubl...-hardware-devi...
    05-29-2024, 02:01 PM
  • GLISIT
    Asus Probook P5440UF-XB74 power issue
    by GLISIT
    Hi all,

    TL;DR - this laptop is driving me nuts with the oddball power-related behaviors. Appreciate any insight you can provide!


    I'm experiencing a power issue on an Asus Probook P5440UF-XB74. Although I've worked with electronics and computers for decades, this is my first attempt at getting into motherboard-level component troubleshooting. Any help the community can provide is greatly appreciated!

    A few weeks ago I was using the laptop (on battery power) for a Zoom meeting. The battery was running very low (long meeting) but I wasn't worried about...
    01-16-2025, 02:29 PM
  • sam_sam_sam
    Mitsubishi CNC switching power supply board dead / relay board bad diode failure
    by sam_sam_sam
    I was working on this CNC machine today found no keyboard functioning no control relay powering on
    The screen powered on and was giving an operation error but the manual was not very clear about what the error exactly was but with a little bit of troubleshooting and finding out that the control relays not powering on and no keyboard functions we narrowed down to this one switching power supply which of course does not have any indicator LED light they are on the keyboard interface/relay controller board

    Found shorted diodes on main controller relays there are 3 of them that...
    01-07-2023, 05:43 PM
  • shovenose
    Ubiquiti Unifi PoE Switch US-8-150W Power Supply Failure
    by shovenose
    Got this one for free because, well, it no worky.

    A little research and there are tons of complaints all over forums/the internet about premature failure of these switches. The observation everyone makes about these is "they run hot" and failure occurring as soon as 13 months, right out of warranty, of course.

    Upon removal of the cover I found a G0398-15011480A power supply that, when plugged in, was making a constant ticking noise. Multimeter confirmed the PSU was the issue. Output was cycling between 0 and about 20V. With output disconnected it sat around...
    08-11-2021, 01:26 PM
  • Loading...
  • No more items.
Working...