Hi EHT, thanks for your reply. Are you sure you're not confusing the old model (SUA750I) with the new SMT750I?
Mine is the older model without LCD, doesn't have upgradeable firmware. It has an Intel OTP micro, and a 93C56 EEPROM that stores UPS model, calibration data, serial number, etc. Seems like APC only made one firmware for the entire line of Smart UPSes. The UPS type is stated in the EEPROM, so if that value is changed, it will not only affects the model number and their behavior but all voltages, frequency, battery capacity, etc will be in wrong value.
The EEPROM contents in this UPS is screwed. Most data is read as FFh, so I will have to start experimenting with the hex values. (Hopefully it won't blow up
)
PS Windows ME !?
yep.
That's the only laptop I got that has a serial port.
Oh, and the caps... It mostly depends on temperature, the quality of the capacitor itself, and luck
. If your UPS is old enough, you may want to change the electrolytics with better brands, just in case... And there are only a few of them anyways. My unit was manufactured in 2001 and all the caps are still fine, but as a precaution I'll change them when I managed to sort out this EEPROM problem.