Dear All
please do not flame and cast aspersions on each other. Life is too short and I value all the suggestions no matter how strange they might appear to others.
It is clearly difficult to diagnose a fault from a distance and the fault with my G5 appears to be not that straight forward.
I am happy to spend time trying to discover a solution as this is my first mac to appear to have fallen over. I started with a 128 Mac in 84 – possibly one of the first in the UK and I still have all the macs I have had over the years although not used actively if at all.
Let me for clarity describe again the sequence of events and the symptoms.
It began when the G5 refused to boot. There appeared to be nothing happening. Of course this naturally occurred at the worst time when I had to finish something. So I took it in to my local dealer and hired an iMac and left it for repair. (Helpfully they told ne that since Apple has declared the Power Mac G5 as obsolete that if it required parts they could do nothing.)
A few days later they said that it was fine – just a failed memory module. So I collected it (two memory modules had been removed) and yea it booted and ran. But after a few hours it froze.
It was only then when I tried to reboot it that I noticed the flashing LED. So I began the process of removing ram. (yes in pairs). Each time if I swapped ram around I could get the G5 to reboot.
So after posting here for help I have done a number of things.
I have looked at the possibility of renewing the thermal paste on the cpu and dismissed it as beyond my capabilities. I have also, when the G5 is running, monitored the cpu temp and it appears to be perfectly normal.
I have run an onyx/Smart check on the hard disk and it reports that it doesn’t appear to have any faults. I do not plan to put another hard disk in as firstly I do not have one, which will fit, and secondly I might as well buy another G5 instead. I would prefer to get this one working if one for sentimental reasons. (In answer to Ronda’s question about the disk capacity – it is the original 149 gb with 115.92 gb used and 33.12 available. I doubt that it would be a virtual memory problem as it hasn’t been required to do any heavyweight processing recently.)
I have now looked at the pram battery and surprisingly for a battery in use for 8 years it is in very good condition. Still measuring almost full voltage.
So yes we are probably back with the memory modules. There are eight – original two pairs of 512 and two pairs of more recent I GB.
At the moment I am going through the memory modules to try and isolate if one of them is bad. The problem is that when I ran memtest the first time I got the results which are above in the discussion which indicate bad memory – but subsequently all the tests I have run has given the result “all tests passed” but in spite of this when the modules has ‘passed’ the G5 will not reboot after shutdown or wakeup after sleep.
When attempting then to reboot there is the 3-flashing LED.
The problem though is that in trying out the different memory modules – the results are inconsistent. A pair of 256 might work in the morning with an ok memtest but not later in the afternoon.
There is a new recent problem – I can get it to boot but then when it is supposedly finished booting it freezes almost immediately.