Imac G5 Shuts Down or Message to Reboot

Question

My Imac G5 1.8 sometimes just shuts down while it is sleeping. It doesn't always do it. Also I get this box on the screen telling me to reboot. The screen goes all fuzzy. The second issue happened when the logic board went a few years ago. It was replaced under a recall. I think the logic board is going again but I think the first issue is something totally unrelated. After doing some reading it might be the battery. Any thoughts?
I have been trying to get a Genius appointment to figure out what is wrong but that has been impossible. It is very frustrating that their appointment scheduler only goes out a couple of days and you cannot schedule a week in advance.
I am starting to doubt Apple's quality. Two logic boards in 5 years is horrible. My 1st Ipod went after about 4 years. Now my second generation Shuffle doesn't work with I-tunes 9.0.

Answer 1

Simply by processor speed, your machine does appear to be one subject to the issue involving defective electrolytic capacitors on the logic board. When Apple first performed board exchanges under the now defunct repair extension authorization, a contract manufacturer responsible for refurbishing the boards typically replaced only the units which exhibited physical defects before returning these boards to the service parts stream.
We take an entirely different approach, replacing all of the capacitors which may eventually fail, not simply those that exhibit the issue.
Write to the electronic mail address in my Public Profile and I will reply with a short illustrated guide to determining if you are affected by the issue, and outlining the option to have your board refurbished for $ 189.00 if your are affected, and wish to do so.