Did I Fry My UPS?

[BillP]

Fighting a cold and lack of sleep so should have known better.  Putting a new battery in a BN600G UPS and in the process of trying to orient the battery in the unit I accidently switched the positive and negative connectors.  Embarrassing but it happened.  Hooked up what I thought was the negative wire, a quick spark and I fear my UPS is, as we used to say, fubarred.  Reversed the connections to their proper polarity, plugged unit into electrical outlet and got chirps, blinking lights and clicks.  Also a tiny spark when inserting the power cord into the outlet.

Am I correct in assuming the UPS is now only useful as a doorstop?  I'm guessing the battery is still good.

[Anonymous user]

well.....answer is simple...

connect the battery, correct way this time....and simpy turn on the UPS.....if nothing blasts, you are on good way 🙂

now, plug some light bulb, if it lits, you are almost there 🙂

next step is to plug the UPS into the wall mains and try the same....

now, take some multiumeter and check the voltage on battery terminals.....when UPS is turned off and unplugged from the wall plug...DCV on battery terminals should be 12.6 - 13V usually...when you plug into mains ACV, charger should raise the voltage so you will start reading increasing of voltage on battery terminals...up to 13.6V usually....

if thats not the case then in worse case it got blown the charger level....

not sure what type of charger is in it....older versions have had LM317, if it is SMPS with IRF fet usually or with universal chip TNY255G...in any case  cost is around 2-3$ for parts and  plus service charge of electornics technician if you dont know how to do it on your own....

[BillP]

Checked the battery and multimeter is showing 12+ volts.  Hook up the battery and get nothing when I try to turn the UPS on.  Plugged a small fish tank pump into a battery connection and got nothing.  Plugged the UPS into an electrical outlet and turning it on produces a red blinking light and loud beeps.  The fish tank pump runs if I plug it in while the UPS is connected to the electrical outlet.  I'm guessing now I have a new doorstop.

[Anonymous user]

well...it seems output mosfets are in short circuit....or just charger fet so the logic doesnt let the UPS to initialize...

from this point it is hard to say without visual inspection and of course; measurement/testing point of particular components inside....so, on a first sight, if you are not skilled how to test the semiconductors and electronic components inside, then yes, you got the new "doorstop"

well...you can always use it as "extension cable with few plugs"....since surge outlets are actually directly connected with wires of surge cable...

service at official service is simple not worth, doesnt pay off.....unless you got some friend more skillful to help you and repair it for few bucks...

it is better to try to buy another one like that from 2nd hand, without battery (you can get it for 10-20$ with dead battery), then use your battery and this fried leave for "spare parts" 🙂

[BillP]

Thank you Vlad.  Fortunately the UPS is not very expensive so I think I'll just replace it. 

[BillP · Accepted solution]

Seems like you may be a prime candidate for the Trade-Ups program, so at least you will get a small discount from your doorstop