DC bus overvoltage fault on SURT10000XLI

[BillP]

Hello

There i have a SURT10000XLI made on 2008 .my UPS first fault was 'BATTERY CAPACITOR SOFT START ' after fixing the PFC (ic904 and ic903) and resistor that was near the ic and replacing the D921 and 922 my ups fault changed to """"""" DC BUS OVERVOTAGE FAULT"""""" !!!

Would you please please please guide me which board should be repair ?inverter board or PFC board ?? the surt manual refer to inverter relay , does it mean the inverter relay weld ?

i'm waiting for your QUICK response

thanks.

[MarkC_apc · Accepted solution]

I realise this is an old post, but I've had the same fault error code (08) thrown on a SURT6000 (second battery LED on with fault LED on).  The repair manual states this is an "auto-recovery" error, but obviously something is wrong that is not recovering.  I've checked the high voltage relays and all appear to be proper continuity and impedance across the coil.  The unit seems to run on batteries OK - just happens when mains are connected.  

Any suggestions?