Hi,
I have been doing a lot of reading here trying to come up to speed, since I'm new when it comes to these things.
I have an APC BACK-UPS 1250 which was recently given to me. There were two dead batteries in it, I had the correct batteries for this UPS. When I went to connect them I was very surprised when there was a rather large spark at the battery terminal when the negative cable was connected! I don't remember any of my other UPS units doing this. I plugged it in and pressed the on/test switch. The fan came on and the unit passed the self test. So far, so good. I plugged in my halogen lamp then pulled the APC's power cord and the halogen lamp remained on. Better yet! I let the lamp run for about 10 minutes and watched the battery reserve drop. I plugged the main power cord back in and expected the battery to recharge but the display didn't move. OK, the inverter part works but the battery won't recharge. Noticing five cheap Teapo capacitors on the board gave me the idea to recap the circuit board, all 10 of them. Other caps were marked Surge, a few were IC branded. Replacing them was relatively easy then afterward I did a continuity check between the new capacitor's pin and where the trace led to on the board. I powered on the UPS. Luckily, no smoke was let out and popping noises were not heard. But now, it won't pass the self test. After pressing the on/test switch you can hear the relays click then the load display goes to the red. The alarm comes on and stays on until you press the main switch on the back.
I ordered Panasonic ECG series general purpose capacitors from Digi-Key. I selected the exact microfarad and voltage as the ones I pulled out, 20% tolerance 85C. I didn't pay attention to the series designation or any ESR information, I just ordered plain aluminum capacitors that were close to the physical size I needed and I didn't have to order 20,000 of them. Did I order the wrong ones? Do I need 10% tolerance or something else?
I double checked the polarity orientation of the capacitors before soldering them, it is correct.
I need to get back to at least where I was before "fixing" it, where to start?
Any help would be much appreciated.
I have been doing a lot of reading here trying to come up to speed, since I'm new when it comes to these things.
I have an APC BACK-UPS 1250 which was recently given to me. There were two dead batteries in it, I had the correct batteries for this UPS. When I went to connect them I was very surprised when there was a rather large spark at the battery terminal when the negative cable was connected! I don't remember any of my other UPS units doing this. I plugged it in and pressed the on/test switch. The fan came on and the unit passed the self test. So far, so good. I plugged in my halogen lamp then pulled the APC's power cord and the halogen lamp remained on. Better yet! I let the lamp run for about 10 minutes and watched the battery reserve drop. I plugged the main power cord back in and expected the battery to recharge but the display didn't move. OK, the inverter part works but the battery won't recharge. Noticing five cheap Teapo capacitors on the board gave me the idea to recap the circuit board, all 10 of them. Other caps were marked Surge, a few were IC branded. Replacing them was relatively easy then afterward I did a continuity check between the new capacitor's pin and where the trace led to on the board. I powered on the UPS. Luckily, no smoke was let out and popping noises were not heard. But now, it won't pass the self test. After pressing the on/test switch you can hear the relays click then the load display goes to the red. The alarm comes on and stays on until you press the main switch on the back.
I ordered Panasonic ECG series general purpose capacitors from Digi-Key. I selected the exact microfarad and voltage as the ones I pulled out, 20% tolerance 85C. I didn't pay attention to the series designation or any ESR information, I just ordered plain aluminum capacitors that were close to the physical size I needed and I didn't have to order 20,000 of them. Did I order the wrong ones? Do I need 10% tolerance or something else?
I double checked the polarity orientation of the capacitors before soldering them, it is correct.
I need to get back to at least where I was before "fixing" it, where to start?
Any help would be much appreciated.
