My Dead UPS (Uninterruptible power supply) (1200VA-720W)

Discussion in 'Power Electronics' started by q12x, Oct 15, 2018.

  1. q12x

    Thread Starter Member

    Sep 25, 2015
    58
    3
    I practically blow up my UPS (1200VA-720W) 1 week ago.
    I wanted to attach a led to the main board and probably (i am not sure) my thick copper soldering tip melted 2 very close nodes together, OR the flux made a capillary connection between 2 very close nodes; and short circuit some SMD and normal components on the main board, with sparks and smoke. My morale was -10 at that point. I asked the repair company if they can send me a new electronic board and they just play dumb. Ok... so I have 2 good accumulators, 1 good transformer, some wires, the LCD display, and the case.
    I was thinking today if is possible to build myself the board !
    My electronics skill is medium, I know some stuff, but i am not an engineer. I am a electronic hobby guy - tinkering in 30 years of my electronic life. I also lack some fundamentals too, I admit it. But I am not a rookie!
    So, please tell me there is a chance to undo my mistake. Tell me there is a second chance.
    While the board was working, and I was hunting for nodes of lower voltage to attach my led, I realized how this thing is working. Basically, when charging, (alternative) ~220V enters in transformer primary, ~24 is output in secondary, some components (i've seen a bridge there with large transistors and large aluminum radiators) transform it into || (continuum) 24 and split it by 2 >> 12 for each accumulator. When the Power is down, 24 || continuum is transformed into (alternative) ~24, goes back into transformer and out to power my computer. The thing is that it also powering my computer while charging also. This is what i observed by myself, i didnt read anything about it.
    - I would like to make myself the schematic (very straight forward) if is possible.
    OR,
    - to buy a ready made alternative board for a general UPS?
    What are your suggestions?
    Thank you.
     
  2. Reloadron

    Distinguished Member

    Jan 15, 2015
    4,450
    2,181
    Without knowing the actual damage done it's hard to say. My thinking is just replace the UPS. While a $150 USD lesson is expensive unless you can get back in there and find the damage like a shorted bridge of circuit board runs and hope nothing else was damaged trying to find and replace damaged components is like an exercise in futility. A picture may help or a few good sharp and clear pictures may help.

    Ron
     
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  3. q12x

    Thread Starter Member

    Sep 25, 2015
    58
    3
    Thank you Reloadron. The damage is extensive. A couple of SMD puffed with a white smoke around them, and in the same time smoke under the board was becoming thicker until a large condenser fall out physically. It poped out. It fall. I imagine the tin melted. Also, a sizzle noise i hear. But i dont know from where. This noise wasnt there before. The damage is in a lot of places. I dont think i can repair the board. Also, i dont have the right components to play with them until i can repair it. I have to order them online, so it's very time expensive this way and very unsure from my part i can resolve it.
    I can make some pictures of course. Just to show you the general structure of the UPS. The damages on the board are not visible, so it looks like its new.
    It is a very hard subject, i suppose. I still believe it can be repaired - with the right people.
    I will make the pictures and post them soon.
    Do you have a basic/simple scheme in mind? Can you post it?
     
  4. q12x

    Thread Starter Member

    Sep 25, 2015
    58
    3
    images:
     
  5. DickCappels

    Moderator

    Aug 21, 2008
    5,745
    1,800
    Were traces damaged?

    This might be a good time to try and identify the broken parts. What can you say about them other than the are damaged surface mount parts?
     
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  6. q12x

    Thread Starter Member

    Sep 25, 2015
    58
    3
    Good sugestion DickCappels . I dont see the (copper) traces are affected... I dont see any evident blow up trace anywhere. I didnt look for them to be honest. Usually they are very evident. I decoupled (black) battery wire as seen in the image, because something was boiling (sizzle noise) and i could smell hot metal somewhere on the board. I also used a cheap digital Thermometer on various locations on the board and on that 'bridge' with Aluminum radiators, the temperature was 105 gr Celsius. Very hot! On the green side of the board, there are the SMD components. In the middle of it is a black V thing - that is 2 resistors with black band isolation to reduce the speaker volume. The V is directly on the 2 speaker pins. Also from here I collected the led power too.
    All the tests i did worked !!!!!!!!! Speaker was not so loud, the led worked, and the fan. I put a fan too but i collected the voltage from other part of the board, and it was not in power when the board blow up.

    In the end, when i had to make all the "elegant"/"clean" connections, then I blow it up. I know the flux flowed a bit too much 5 seconds before the short, but i didnt think it will be a problem so i Power On, then Puff, a chain reaction of broken components as I described.
     
  7. q12x

    Thread Starter Member

    Sep 25, 2015
    58
    3
    OHO Mister DickCappels ! I continued to look very closely and I really found a blow copper trace and a SMD missing from it's spot. Check the image attached. I think is a condenser - i have some SMD condensers around , but i will have to guess the value of it.
    I also think that my resistor metal leg touched the smd component behind it. It was very low bent toward the board. I looked now more closely and it looks like that leg is the main cause. Very interesting. I did isolate the 2 resistors but their legs were free to bend and to touch the next nodes.
     
  8. ArakelTheDragon

    Well-Known Member

    Nov 18, 2016
    1,262
    101
    The traces can be on the middle layers (inside of the board) in which case you can do nothing.

    Using a cable to bypass the broken traces is one of your options, but it will be hard and this is a hazard as you are working with middle voltage equipment with no protection and no training.

    It is possible to replace the board if you know the input voltage, current, frequency and the output voltage, current, frequency. But someone will have to design a board for you with these parameters, also it might be expensive to make this board with high voltage electronic components.

    Buying a new UPC from "eBay" might be better.
     
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  9. q12x

    Thread Starter Member

    Sep 25, 2015
    58
    3
    To Mister DickCappels ! I managed to repair the copper trace. I also think that "missing" component is not really missing, since i see a lot of similar components nodes with only the red glue in there, all around the board. So it can be like that from design. Anyway, i put the battery connector on, it sparked on contact, but a very beautiful Blue spark was inside that bridge again. No smoke this time, only relatively big spark. Probably that condenser again? I know i discharge it before, probably now it charged with a spark? Who knows.Is still not working.

    To mister ArakelTheDragon. You have a very good idea actually. Can someone build this board for me? Just instruct me what to give you : like you said: "input voltage, current, frequency and the output voltage, current, frequency." I think i can give you this data. From the transformer and from the accumulators. I will pay for it. Hopefully not very expensive - I would like an estimative price first before starting anything. I am curious how much it can cost. Don't you? From the top of your head how much can it cost very roughly.
    - Yes in the end i will buy another UPS but i want to try to get cheaper first. I think is possible with a little help from you!
    And thank you all - you are very helpful !
     
    Last edited: Oct 16, 2018
  10. q12x

    Thread Starter Member

    Sep 25, 2015
    58
    3
    ME-10545-E2L transformer name
    M1707 15S accumulators name
    I searched on google for these and nothing found.
    -
    input voltage, current, frequency (input to the board from the transformer secondary)
    output voltage, current, frequency (output from the battery)
    -
    Input Frequency is Main wall outlet frequency 50Hz. Transformer don't affect it in secondary (i hope).

    -
    output voltage (from Battery) is 25V (because they are in series wired). I also noted that value on the board when I hunted for voltages spots.
     
    Last edited: Oct 16, 2018
  11. ArakelTheDragon

    Well-Known Member

    Nov 18, 2016
    1,262
    101
    We already know how much it costs, I agree with Dick, the traces are most likely the problem, and I guess its possible that you have damaged the middle traces.

    A 400 dollar price would be something normal.

    Its better if you search for replacement board in google and try to buy one cheap(but you will need the serial number or at least the board model and to usk us will it work).
     
  12. q12x

    Thread Starter Member

    Sep 25, 2015
    58
    3
    My UPS cost ~70$. And others more new brands are around 100$ with lower VA and lower power. I speak about the cheapest ones. I know there are very High VA UPS's and very expensive like the one you describe - probably you are referring to those. Mine is low (but not the lowest) 1200VA 720W. I want to make the electronic board in the 10-20$ range or something very cheap. I know is possible. The problem is that 70$ for me is a real budget black hole.I cant permit these sums too often. To buy another one is too much money for me to spend, that's why i reach to you guys here. You should be happy that you have a very nice project to work on, helping me repair my Ups.
    I dont know how to search this board on google - maybe you know better than me what to find and where?
     
  13. ArakelTheDragon

    Well-Known Member

    Nov 18, 2016
    1,262
    101
    This was unneeded "You should be happy that you have a very nice project to work on, helping me repair my Ups." But I understand your pain.
    If we can not help you to repair it, I suggest this:
    https://www.ebay.com/itm/CyberPower...2be477:g:KjwAAOSw6-Nbw9-6:rk:33:pf:0&LH_BIN=1

    So far try to use a cable to bypass the broken traces, and do not use the same solderer!
     
  14. q12x

    Thread Starter Member

    Sep 25, 2015
    58
    3
    I managed to repair the copper trace. I also think that "missing" component is not really missing, since i see a lot of similar components nodes with only the red glue in there, all around the board. So it can be like that from design. Anyway, i put the battery connector on, it sparked on contact, but a very beautiful Blue spark was inside that bridge again. No smoke this time, only relatively big spark. Probably that condenser that fall off before, now again? I know i discharge it before, probably now it charged with a spark? Who knows. Is still not working.
     
  15. q12x

    Thread Starter Member

    Sep 25, 2015
    58
    3
    I looked on your link - 38$ is a good price indeed - thank you very much !
    It says Outlets: 10 (5 surge, 5 surge + battery backup) - i only need 1, but fine with 10 also. I wish something with 1 outlet and cheaper? But this is a very good find !!! I am not complaining, i am just digging for cheaper versions.
    Shipping: FREE Economy Shipping (Excelent !) - they throw here a lot of $ sometimes.
    1100VA - mine is better 1200VA - but is close to mine, so is wonderful.
    I searched for [UPS PC] on ebay too, and this one is the cheapest possible indeed.

    And is for americans... Output: 120 VAC - I am european with 220V in my wall socket.
    (can it be converted to 220V?)

    I wonder if you can find a UPS Board there too. I didn't search but I trust you more - you have a keen eye on these things, i can tell. I will search for one also.
     
    Last edited: Oct 16, 2018
  16. ArakelTheDragon

    Well-Known Member

    Nov 18, 2016
    1,262
    101
    Dont dig too much as you might reach the center of the Earth (I have made this mistake before).

    Please do not repair traces unless its with a cable and after that check them with a multicet(multimeter).
     
  17. q12x

    Thread Starter Member

    Sep 25, 2015
    58
    3
    i repaire it already - i put a component leg there and i checked it for continuity and is ok.
    I also test it but something else blue sparked, probably a large condenser on accumulators output (on the board). It is still dead.
     
  18. ArakelTheDragon

    Well-Known Member

    Nov 18, 2016
    1,262
    101
    it is possible that during the first smoke outburst, something burned, maybe a defence, maybe a capacitor. My best guess is a capacitor. If you can check the capacitors with a multicet it would be good.
     
  19. q12x

    Thread Starter Member

    Sep 25, 2015
    58
    3
    update
     
  20. ArakelTheDragon

    Well-Known Member

    Nov 18, 2016
    1,262
    101
    Please avoid connecting the power until we can diagnoze the problem, as you might burn something else.
     
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