Won't retain date/time, won't boot after normal shutdownn

I looked through all of the prior questions and found hints that seemed helpful, but didn't fix this problem. This is a used G4 MDD, dual 867Mhz processors, when I connect it to AC power it will boot up, but the date and time are wrong. I can reset them fine, and while I have the unit running it appears to be fine. I can tell it to reboot and it does so, and retains the date/time settings. If I shut it down normally, it does that fine, but then it will not reboot until I remove AC power then reconnect it. The chime is always at full volume, too. I have checked all the connections and replaced the PRAM battery with no change.

On a note that I'm not sure is related, I have a drive that already has OS 9 on it that I would like to drop into this machine, but when I do the machine will not boot. The drive is a Seagate model that worked fine in my older 500Mhz G4. I'm beginning to think I've grabbed a mess here.