Some some advice from folks how about #APC #USP. I got a old #BX700U. When connecting power nothing happens, no LED no beeps. When pushing the front button regardlessly if long or short also nothing happens. I've opened it and I'm measurung 0.52 V at the battery pins. Before ordering a replacement battery what else can I check to validate the device itself is still ok and it's just a degraded battery pack inside? Any hints welcome. #fedihelp #followerpower