Unable to communicate with battery backup

[Anonymous user]

I have had a BE750BB UPS for over 5 years now and it has worked fine. I just built a new system w/OCZ ZT750 Power Supply. I installed all my software including Power Chute and the battery backup was 'seen' fine for the first 3 days. On the 4th day I started receiving the message - Computer unable to communicate with your battery backup. I have tried everything I have seen suggested on other posts concerning the same problem but with no success to having it work again. The USB cable is plugged into a USB 2.0 port (tried different ones) not a 3.0 port, done a System Restore back to a time when it was initially working to no avail. I have been reading about the new power supplies being PFC and the pure sine wave questions/discussions but I'm not sure that is relevant to this since it did initially work although even APC states only backups manufactured since mid 2008 shouldn't have an issue w/PFC power supplies.

[Anonymous user]

I didn't find anything externally wrong with the cable when I unhooked it from the unit. And that reminds me of something else I forgot to include in any of my posts; I had to unplug the USB end from my PC otherwise it wouldn't go to sleep. Serial #3B0639X43954.

[Anonymous user]

Yes, and it won't reinstall because it 'can't find' the battery backup. Also, when the USB cable is plugged in it only shows as an Unknown Device in Device Manager under the USB section and the PC won't go to sleep.

I haven't tried switching to the backup with the PC on but everything stays lit that is hooked to the battery side plugs when I cut power to the unit. From what I've been reading the majority of people say there shouldn't be an issue with the PFC power supply but not sure I want to find out with such new parts. Reminded of that saying about a little knowledge ....

[BillP]

Have your tried to reinstall the Powerchute software?

Otherwise the ups is stiff functioning properly right?

[BillP]

Try this; unplug your computer, plug the usb cable into a different computer and install powerchute then see what happens

[Anonymous user]

I must have done something wrong since that part of my post didn't show up with the original post. I had hooked the unit up to my laptop, battery removed, and proceeded to (try) and install Power Chute and it went so far and then said it couldn't complete since there was no battery backup installed. I noticed it showed up as an Unknown Device there also when the USB cable was plugged into that PC.

[BillP · Accepted solution]

If the unit is showing up as unknown device on all computers there may be a problem with the ups or cable, check the cable thoroughly for tears, what is the serial number of the unit?