It’s funny how many people hear something from a source they consider authoritative, assume it’s the gospel and repeat what they heard as fact.
LC 475 won’t start without a PRAM battery? Nonsense. I’ve just restored an LC 475 logic board and it booted first throw of the switch, and not a PRAM battery in sight. It didn’t know which century it was in, let alone the time of day, and it won’t remember those settings without a PRAM but that’s the only side-effect. Otherwise it’s a very happy little Mac.
In over thirty years of using and repairing Macs I’ve never come across a single unit, 68K or PPC, that failed to boot as a result of a missing or dead PRAM battery. I wouldn’t deny the possibility of dead or missing batteries causing issues but to categorically state a specific model won’t work without one is misleading at best, especially when it’s repeating something someone else has said without any validation.
Anyone hearing repeating clicks or chirps at startup from their old Mac needs to replace ALL the filter/smoothing capacitors on the secondary side of the switching transformer. Simple as that. If they haven’t leaked yet they will do, causing varying degrees of corrosion and potentially damaging the PCB beyond repair. PRAM batteries are worse. ALWAYS remove the PRAM battery before putting an old Mac into storage because they WILL destroy your logic board when they finally take a leak.