I have a 2003 iMac G4 1,25Ghz 17".
It runs fine and I have not had any problems except this annoying issue - it takes several attempts to get it to start-up.
For example, first thing in the morning, I press the
power button and it locks at the white screen with the
grey apple logo with faint grey or white vertical lines.
I repeat restarting the iMac with the power button and it happens three or so times and usually boots up fine to the Desktop on the third or fourth attempt. After that it runs fine.
I have changed the internal HDD as it was failing with
a new unit, upgraded the RAM, changed the PRAM
Battery, zapped the PRAM and PMU, repaired disk
permissions and even tried a clean install of the OS.
In addition, I had a look at the logic board and all the capacitors looked fine and all connectors were in. It has lead me to think it may be the PSU that is on its way out? System diagnosis is fine, RAM is OK and there are no common symptoms of bad capacitors on the logic board like freezing, crashing and graphic artifacts on screen.
I do not have the Install discs that came with the computer and I believe the Apple Hardware Test (AHT) is on disk one, only the five Software Restore discs. The iMac has Leopard 10.5.7 on and is all up to date. The Apple Support site does not have this specific model AHT for download unfortunately.
The previous owner (first owner) said he never had any problems but admitted the iMac was rarely turned off - it would go to sleep when it was not being used.
I would be most grateful if anyone could throw some light on this or share similar experiences before I start spending money on replacement parts in the hope it may fix the issue.
For the last 72 hours the iMac has been left on (it sleeps while I do) and I have had absolutely no problems with it. It powers back on from sleep without fail.
Thanks in advance.