Basically a DC to AC inverter with voltage and current protection circuits. However there are also wave shaping circuits in the AC production section of the device. In-depth troubleshooting and diagnostics may result in determining what device is causing the fault however getting appropriate replacement components may be the challenge. BE advised, the circuitry produces voltages that may be considered lethal when in operation. Follow all the safety rules endemic to this kind of service. IMHO: APC makes some rather nice products, almost all are not consumer serviceable.<
Most certainly. if the Battery is totally dead, the UPS will not do a sausage. Test with car batteries matching the voltage reqd. If it springs into life, buy new batteries. I have about a dozen UPS devices around the house all bought as Dead. New batteries fixed EVERY One.
Range from APC BackUPS300 to SmartUPS1400VA, must be a few quids worth if bought new. Gel batteries are pretty cheap nowadays too
Some of these have automotive-type blade fuses in the battery line on the circuit board. Also, as has been mentioned, try a new battery. I have had good luck with Power Sonic and Panasonic brand gel cells.
Note that most of these will go into a test mode for a few seconds on startup, and when this happens, quite a large current is drawn from the battery for a moment. If you are lashing up some random battery you have lying around, use wires at least as large as the ones already in the UPS. I tried to start up a APC Smart-UPS 600 with not quite the right batteries and a cheap ~20 gauge clip lead and melted the clip lead.
If you get it running, but it complains about a low battery even when you know the battery is fully charged, go to
and read the answer to "Q: I replaced the battery in my APC Smart-UPS and now it thinks the battery is low all the time. How do you fix this?"
We are using a fair number of UPS's around here. We found the APC to be one of the best. You will find that ALL of the UPS manufactures will NOT supply ANY service manuals or schematics, or parts.
If your APC unit is dead, there is a 99.9% chance that it is the battery. Most of their models go in to a protect mode, and completely shut down when the batteries are warn down.
Replace the batteries with the same amp hour and voltage rating, in the same combination. This is a safety thing for having the proper charge and load current. If you buy a set of generic batteries, make sure that the terminals match, and that you transfer the thermo fuse (if there is one), that is one stuck on to the battery assembly. This fuse is very important to have in there.