Gene Langlinais wrote:
Had the same start up problem. MAC diagnosis $65.00 deturmined it's the power supply. Don't know if it was a lightning strike of just died. Anyway I'm looking for a new(er) power supply. All I've seen have been expensive. Gene Langlinais
Thanks to everyone for the responses so far.
Today, I took the iMac apart, blew the dust out, and checked the 3.6V PRAM battery. It seemed fine (reading 3.7V), so I tried resetting the mother board by pushing it's reset button a few times. Reassembed everything...no dice. Still behaves the same.
A power supply failure seems reasonable, but I'm surprised it would only
fail part way. It still has enough power to trigger the startup chime and spin up the fan. I'm no expert on power supplies...anyone know if they normally fail half way? I would expect it to be all or nothing.
If so, that would make sense. It may be shutting itself off when it tries to power up the monitor...not enough juice. Assuming that's the case, I will probably try to sell it as-is on ebay. I don't think I'll recover the time and money required to get this thing fixed. I wish I had a better option, but fortunately broken iMacs seem to sell fairly well on ebay.
Thanks again for all the help.Paul Rybarczyk paul at rybarczyk dot net
<< A power supply failure seems reasonable, but I'm surprised it would only
fail part way. It still has enough power to trigger the startup chime and spin up the fan. I'm no expert on power supplies...anyone know if they normally fail half way? I would expect it to be all or nothing. >>
I'm no expert on Mac power supplies either, but I would strongly suspect that the supply generates several different supply voltages. If one is out, and the others are ok, strange things could happen.