BE550 no power on battery backup outlet

[Anonymous user]

The BE550 just passed the 3 year warranty period, and suddenly, no power on the outlet of battery backup + surge protection.

LED is green and no other alarm sound, all behave normal.

During the power on, there was a period of having power on the outlet, but just for a few seconds.

The strange thing is, at this condition, if the AC input is disconnected, there is power on these outlets and connected device works fine, with periodic alarm to indicate the AC line is off.

I tried only putting a switcher, a few watts load, on the outlet and the symptom is the same.

The surge protection only outlets are working fine.

Any idea on this problem?

Thanks!

[mitsmith_apc]

Hi Congshi,

I would try what we call a brain dead. Turn off the unit, unplug it from the wall, and disconnect the battery. Wait about 30 seconds. Re-connect the battery. At this point I would turn the unit on via battery power by holding the power button. If it turns on (which it sounds like it should based on your description) verify there is power from the outlets and then connect it to the wall plug. At this point it should transfer off battery power. If it stays on battery power that tells me that it does not see good input power. If it transfers off battery power (the beeps stop) and the power from the battery outlets goes out I would think that there is some sort of short internal of the unit. 

[Anonymous user]

Hi Michael,

Thanks for the advice.

Following your steps, the unit turns on by battery normally, the outlets have power. Once the AC cord plugged in, with one click sound, the power is disconnected from the outlets. So it must be what you said “there is some sort of short internal of the unit”.

Would you elaborate a little for “there is some sort of short internal of the unit”? Some parts dead?

Thanks again for the help!

[Anonymous user]

Before you give up on the unit, check its built in circuit breaker to see if it might have tripped. (Of course, if it did, it's also possible that the circuit breaker did not survive the experience. Sometimes they don't.)

[Anonymous user]

Hi Michael,

The problem has been fixed, thanks for the advice.

I opened the box. Since I just saw one relay, I measured the relay working voltage, which was just above 10 volt when AC in. Then I saw some brownish stuff on the PCB board along the relay driver. I wiped them off with swab and rubbing alcohol. When turning it back on, the relay working voltage is about 13 volt and the outlets have the power!

So the problem is the leakage in the relay driver, which makes the drive has no enough power to drive the relay properly. Although the click sound is heard, it just turns off the battery power but not contact well to the AC line.

Thanks!

[Anonymous user]

Hi William,

Thanks for the reply.

Since the surge protection only outlets are working fine, it shouldn’t be the circuit breaker. The circuit breaker control all AC input.

[Anonymous user]

Sorry about that, I misread what you wrote. My next thought was that of a relay or relay driver fault. It might not be a bad idea to touch up the solder joints on that, if you're equipped to do so. My guess is that while cleaning the pins couldn't have hurt, the solder joints could probably stand to be reflowed as well.

[Anonymous user · Accepted solution]

Hi William,

thanks for your advice. I'll keep an eye on the solder joints.