Problems with Imac G5

I bought this new Imac G5 which was working fine. I moved to a new house recently and when I switched on my Imac G5 I noticed that the performance of the computer has been degraded. When Imac starts, it gives a blank blue screen for a longtime and then the system boots. Also while putting the Imac to sleep, fan makes lot of noise with screen going black with the white light on the bottom of the monitor slowly going on and off. When this happens I am not able to wake my computer up and I need to shut it down using a Power switch. The operating system I am using is Mac OS X Snow leopard. Is this because of some operating system problem? Please help me on this

Imac G5 series users have been facing the problems like this for a long time. It is because of the batch of faulty logic boards which was installed in the Imac G5 series. Getting the logic board changed will solve your problem. Contact your nearest apple service center and get your Imac checked. If your Imac is under warranty then the logic board will be replaced for free but if the computer is out of warranty, then you will have to pay for the part changed and the service charge.

I think you will have to pull out the RAM and then install it again. As you have moved the computer from your old place to new place, it is possible that the RAM may have dislocated from the slots. Open the cabinet and check if the RAM is properly inserted in the slots. To be sure remove the RAM chips and replace them again. If you have multiple ram chips then try booting the system with one ram at a time. If for any RAM chip, the system does not boot then discard the RAM chip and replace all the other RAM chip and check if the system is working fine or not.

Many of the such problems which are faced by MAC users are solved by doing a PRAM reset. PRAM reset clears all the values in PRAM which may be creating the problem. To perform the PRAM reset follow these steps.
1) Locate the following keys Apple, Option, R and P.
2) Now Press and Hold this keys while Pressing the Power button
3) Keep the buttons pressed till you hear three start-up chime.
4) When the 3rd startup chime is heard, Leave this keys.
5) Now let the system boot on its own. Hopefully the problem will be solved after PRAM reset.

By looking at the problem it is obvious that it is a Power supply unit issue. Resetting the Power supply unit will solve the problem. This problem occurs due to stored capacitive charge in the PSU. This capacitive charge is responsible for the screen blinking while the computer is in sleep mode. Follow the steps to Perform the PSU reset.
1. Remove the Power cord and disconnect it from Main.
2. Now Locate the PSU reset button on the Computer.
3. Now press the button and let the computer sit for 30 seconds.
4. Now plug in the power cord in Mains.
5. Now press the power button and while pressing it down, plug in the power cord.
6. Now Press the power button again to start the computer.
Now let the system boot properly and see if the problem persist.

Fan rotating while making loud noise and scree fluctuating while in sleep mode is a problem called as Kernel Panic. Kernel Panic is a software issue which happens due to operating system corruption. My suggestion to you would be to re-install the operating system. Re-installing the operating system will definitely solve the problem. Insert the operating system installation disk in the drive and boot the system from the disk. The Installation screen will come up. Now locate the Options button and click on it. Now select "Archive and install" option which will allow you to reinstall the operating system without touching the installed applications. Hence even if the operating system is replaced, you will not have to reinstall all the applications again.