A nice member of the Vintage Macs mailing list offered to mail me a working LC power supply at cost of shipping. I figured I would take him up on the offer - if it doesn't get my problems sorted, I can always re-gift it later. So now I am waiting on that plus the PRAM battery, and probably won't touch the LC until I get both those parts.
Also, just reaching here: I had a theory on how a bad PSU could have these symptoms. If it needs to hold a certain charge in order to start and sustain the boot, but it can't build up enough power, then the LC could go into a loop of constantly attempting to boot / draining a capacitor / cutting off all power to the board. This would explain the clicking (power cycling) and also why the clicking doesn't start until a couple minutes later (got to slowly build up that initial charge first). Plausible?
Anyway I opened up the PSU to see if there were any obviously bad caps or scorch marks inside, but there was an electrolytic that looked big enough to knock out a horse, so I put it back together without poking around anywhere. The only way I want to be killed by a computer is if that computer is part of SkyNET.
Also, just reaching here: I had a theory on how a bad PSU could have these symptoms. If it needs to hold a certain charge in order to start and sustain the boot, but it can't build up enough power, then the LC could go into a loop of constantly attempting to boot / draining a capacitor / cutting off all power to the board. This would explain the clicking (power cycling) and also why the clicking doesn't start until a couple minutes later (got to slowly build up that initial charge first). Plausible?
Anyway I opened up the PSU to see if there were any obviously bad caps or scorch marks inside, but there was an electrolytic that looked big enough to knock out a horse, so I put it back together without poking around anywhere. The only way I want to be killed by a computer is if that computer is part of SkyNET.