My UPS (CyberPower OLS1000EC) reports ‘output short’ and cuts off power when the PC restarts, particularly when the switching is fast, like from BIOS to M-Flash (MSI’s BIOS flashing utility). It happens erratically. The PC peak load is 450W (7800X3D, 9070XT) on a 750W PSU (Deepcool PN750M) on a 1000VA UPS.
I should say I replaced the 16A wire that came with the PSU with a 6A one as the total load is barely 2A as the mains voltage is 230V, 50Hz.
Claude says it’s an NTC thermistor issue in the PSU- when rapidly restarted, the thermistor is still warm and has lower resistance which draws too much inrush current in too short a time (di/dt). The UPS algorithm then flags this as ‘output short’ and cuts power.
I need to flash the BIOS and am a bit worried. The sequence is as follows-
BIOS -> click on mFlash -> restarts -> Goes into mFlash and installs on loading screen-> restarts
What happens if the UPS cuts off power at the restart after the bios writing is complete? I’m thinking this is better than doing it on pure-mains power because I get erratic power cuts, unlike the UPS which only cuts off on switching.
