Question about APC Back-UPS XS900 (BX900) UPS System

Open Question

Fan noise like sound from APC XS 900 Back-up. Is there an internal fan? Appears to be functional, other then the noise that continues even when its turned off at the switch, or even unplugged.

Posted by on


4 Suggested Answers

  • 2 Answers

SOURCE: I have freestanding Series 8 dishwasher. Lately during the filling cycle water hammer is occurring. How can this be resolved

Hi there,
Save hours of searching online or wasting money on unnecessary repairs by talking to a 6YA Expert who can help you resolve this issue over the phone in a minute or two.

Best thing about this new service is that you are never placed on hold and get to talk to real repairmen in the US.

Here's a link to this great service

Good luck!

Posted on Jan 02, 2017

  • 5 Answers

SOURCE: apc xs 1500 overloads even with nothing plugged


Plz check MOSFET which working in inverter section.

Posted on May 12, 2009

  • 5603 Answers

SOURCE: APC will not stop making noise even after I

Plug it back in and then turn the switch off before unplugging... It thinks you have a power failure when you unoplugged it.

Posted on Mar 12, 2010

  • 169 Answers

SOURCE: I have an APC XS

You need to reset the unit to recognize the new battery, I had same problem with one apc smart ups on the bench the other day.

On ours we had to turn off the unit unplug the battery wait 5mins

press the on key and hold for 20secs

reconnect battery

plug in to mains

and start as normal. We did this but still had very low battery time and the flashing lights, so we disconnected the comms interface, that sovled the problem.

It may work for your unit, suggest you check the manual before you try if you are unsure

Hope this helps
Thanks for using FixYa

Posted on Aug 13, 2010

Add Your Answer

Uploading: 0%


Complete. Click "Add" to insert your video. Add



Related Questions:

1 Answer

How do I Remove battery on apc battery back ups bx900R?

If the batteries are swollen (overhead damaged), I would use a screw driver to gradually lever it out.

May 21, 2014 | APC Back-UPS® XS 900 (BX900R) UPS System

2 Answers

How to open an APC BX900R so I can replace the fan ?

slide the front bezel there is still 2 screws holding in there

Dec 16, 2012 | APC Back-UPS® XS 900 (BX900R) UPS System

1 Answer

Have a APC xs-900 that indicates overload and there is nothing plugged into it. New battery did not help.

change the internal fan its a 18-24V type change it with a ball bearing type and yes a 12 volt will also work, with 120v input fine and under medium load the fan is only supplied with about 15 volts and only reaches 24 volts if the load shoots up or there is a power fail situation

Sep 09, 2010 | APC Back-UPS® XS 900 (BX900R) UPS System

1 Answer

How to use apc rs 900 without battery

No no way to use the ups without battery it will not show mains supply without battery and you cannot use it as a stabilizer you must connect battery

Mar 09, 2010 | APC Back-UPS® XS 900 (BX900R) UPS System

1 Answer

How do i disconnect the RBC40 battery from the APC unit???

Typically, APC's have a removable from of back cover that may or may not be held in with a few screws (sometimes they just snap into place). Almost all of them also have a simply plug in connector for easy battery swapping.

You can even try the APC website seraching for the make and model they may have some tips there for you.

Oct 29, 2009 | APC Back-UPS® XS 900 (BX900R) UPS System

2 Answers

Have brand new APC 900 UPS and when plugged in, both green & yellow indicator lights flash. Non-stop. Left unit plugged in for 18 hours (off) to charge battery as info sheet suggested, but lights still...

Nope! The internal battery is not plugged-in correctly. Unplug the APC unit and open the access door to the battery (it is not dangerous to do).
Re-seat the two wire clips (red & black) to the battery. The positive post has a red mark on it.
Close it up and charge for a few hours before using.

If the symptoms continue, return unit to store.

Sep 19, 2009 | APC Back-UPS® XS 900 (BX900R) UPS System

1 Answer

Ran for about 15 minutes. Hooked up to one

Ether the unit is overloaded or the internal battery is given out, or the overload circuit has failed there are only 3 problems that it could be. Not to go to much in depth on this unit APC does have a garentee and I trust you will call them and tell them this exact same issue if they find the unit is faulty they will replace it even though it may be out of warrenty if you get them on the phone and explain to them they will help I know a Greg over there.

Btw, I’m available to help over the phone in case u need at

Aug 12, 2009 | APC Back-UPS® XS 900 (BX900R) UPS System

Not finding what you are looking for?
APC Back-UPS XS900 (BX900) UPS System Logo

Related Topics:

298 people viewed this question

Ask a Question

Usually answered in minutes!

Top APC Computers & Internet Experts

Cindy Wells

Level 3 Expert

5521 Answers

Jax Planet
Jax Planet

Level 2 Expert

922 Answers

Donald DCruz
Donald DCruz

Level 3 Expert

17130 Answers

Are you an APC Computer and Internet Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides