IMac startup problem

[rterps]

I purchased a faulty IMac that only on first starttup chimed, the power light was red then went to anber, green and then switched off.
I removed the logic board, the steel plate that covers the RAM, removed, re-inatalled theSO-DIMM RAM.
On start up it chimed, I heard clicking, it was searching for something and then stayed on and the screen was blank. So I had the SO-DIMM video card checked by VIS and there was nothing wrong with it.
On reinstall, fir the second time it chimed, clicked once, red amber green then off. I have been informed the problem is normally the analogue card.
Is it possible that the memory is causing the problem and is the second course of action?
From Richard.

[Big Jim]

Hi Richard,
I'm sorry that you are not pulling in the kind of people that can really help you. I couldn't tell you how to get through this, but I can point you to a (possibly) better place to ask your question, it's here:

http://forums.macosxhints.com/forumdisplay.php?f=21

I wish you the best of luck.

Jim.

[Buzz]

The start up procedure lend itself to a bad power supply or dead batter. The chime indicated that the boards are functioning and the RAM is good. The fact that it doesn't stay powered up is obviously a power issue.

[rterps]

Sorry about the delay Buzz. The first thing I did was take the logic board out, remove the metal shiekd covering the CPU and system SODIMM memory, reinstalled the RAM then it started chimed went through quite a few clicks and stayed on. That wotked every time but the screen was blank.
I then removed the VRAM, sent it off to VIS, who checked it, found it was working. After reinserting it it went back to button red, chime, one click, amber, green then off and then ressing the on button did nothing so I had to remove the mains lead and put it back to activate it again. I then changed the battery for a new one, to no avail, the only diference is 3 clicks.
Please advise.