This was originally posted on APC forums on 8/8/2014
First time poster, please be gentle
As per subject line, our SURTD5000XLI died. Approx a week ago there was a power fail through out the night. When we cam into the office in the morning, found the 5000 along with all devices plugged into it completely dead. Suspecting old / worn batteries, we switched the devices over to the backup ups (Dell / EATON 2700), whilst waiting for the new RBC44 batteries to arrive.
New batteries arrived, plug them in. When trying to turn on the error and middle battery light show for about 1/2 sec then it goes dead. Same error with both utility power and no utility power present.
This started to make me think the issue is not necessarily old / worn batteries. Tests reveal the old batteries are worn and were in need of replacing. Measuring ~75VDC per cartridge. New batteries measure ~102VDC per cartridge.
Even though the batteries were in need of replacement, now have a new set of expensive batteries (~AU$1000) and a dead ups to put them into
Being bit of (dare I say) an 'old school tech', have removed and opened the unit to see if there is any obvious damage inside.
After some probing around located Q705 on the power board to be short circuit on pins 2-3. Markings on Q705 'K30N60', a little digging around this appears to be a 600v 30A IGBT, Pin1=Gate, Pin2=Collector, Pin3=Emitter. Collector-Emitter short circuit, not necessarily a good thing. Can see it is on the -400v rail, not quite sure wether it is part of the battery charge circuit or output for AC sine generator circuit(s).
Performed a fairly extensive probe of all other 'silicon devices' in the immediate physical area, nothing else is showing as being obviously faulty.
Apart from this one component being faulty, the board looks almost brand new, no excessive dust build up anywhere, no signs of hot spots.
Does anyone else have experience in this area?
Any suggestions on other areas of the board to check?
Board label: Power BD, LYNX II, DSP 3KVA, 5KVA, 6KVA