Re: APC UPS units - troubleshooting


I resoldered it on the board....

Re: APC UPS units - troubleshooting

Hi, I was finally able to fix it!
I replaced almost all the capacitors with new ones, and it is working again. I still need to check if the battery is being recharged.

Re: APC UPS units - troubleshooting

Hi, thanks for your response.
I noticed that the buzzer gets very hot, so I desoldered it.
You're right, I found a bad 22uF cap near the buzzer.

I measured R155 and is about 10 ohm, is a value a bit high for a shunt.
I think the current is measured through the CT1 transformer, the model is "460-0102C-Z LEI-8 ID30" but I can't find the datasheet.
...

Re: APC UPS units - troubleshooting

Hi, I received the new battery and I did some tests.
The output of the UPS stays on only for one second (same as powered with the bench power suppy)
I noticed in the PowerChute software that the UPS is overloaded, and the input voltage is totally wrong (458V).


And here's the warning that says that the UPS is overloaded


Any ideas on what components I could test?
I checked the resistors that form the resistive divider that is supposed to measure the input voltage, and they seem okay....

Re: APC UPS units - troubleshooting

Thank your for your response.
I attach some pictures I've taken.
I hope the pictures are sufficiently clear....

Re: APC UPS units - troubleshooting

Hi guys, I'm new in this forum.
Yesterday I found an APC Back-UPS 700VA (BX700U-GR) in the landfill.
The UPS is without battery (I ordered one).
I brought it home and immediately did some tests:

I connected the UPS battery lead to my bench power supply (setted at 13V).
The UPS seems to be working but the output outlets stays on only for one second (probably because my bench power supply in not powerful enough).

I connected the UPS to mains and I measured the voltage of the battery leads...