Surt D5000xl error codes

[BillP]

Hi, I am in the process of repairing a mainboard for a SURTD5000XL UPS. The unit was initially dead. after replacing a faulty PWM and transistor and with new batteries I manage to get the beast to turn on. I now see some sort of error code on the LED display. Bypass LED + Fault LED + center LED (on batt charge bar). Is this a loading problem as I only have a monitor connected or a configuration problem or is my mainboard still faulty.I have tried some combinations on the buttons and manage to get the "online" led with "batt charge barr leds" on for about a secound before it changes back to the state metioned first.

a service manual or LED error code table would be very helpfull.

Thanks

[BillP]

is the UPS unloaded at this point? this generally requires a replacement but we don't do repair on them so i don't know what the cause is. the problem is indicated as PFC Failure and could be caused by many different things. it appears to relate to negative and positive DC busses having an issue with their voltage being out of range.

[BillP · Accepted solution]

Thanks, after your suggestion I went back to troubleshooting and found another transistor that breaks through as the unit start up, it was replaced today.

I am now able to turn the UPS on when not connected to mains and it runs purely off the batts. When I connect the mains the no-load condition led comes up "X" as well as the "bypass led". Bypass is not selected in front the slide switch is set to "online" By playing with the buttons I can get the unit to show online "~" with batt leds on but after 10 seconds it returns to the no load and bypass state with a short beebping sound.

I suspect now something on the primary side that is not connected, mains fuse or cable etc.

I am worried that I am loading it to lightly and that my input cannot provide enough current through the wires as I am using standard kettle cord to test, which is highly under rated for this model.

Have attached pics of online (running of batts no input supply) as well as when I have mains connected.