PLZ Help Tech in distress Intermittent Booting issues...

[futurefear]

Ok so First time posting here, seems like a good forum as I've solved many problems from browsing forums other members have posted but cant find one that matches my scenario.

iMac EMC: 2111
24 in white model

Works great until recently one morning coming in would not boot from sleep, no power nothing.

Unplug power, hold down power button, wait few minutes, plug back in and try to start,
Fan spins up white light starts to come on, then it shuts off (withing a few secconds), basically same behavior no matter how long i leave it unplugged, or hold power button except sometimes the screen flashes white for a moment too before shutting down. Once this cycle completes I will get no power or response until unplugged/plugged in again.

Here's the weird part, if I reseat the ram during this power cycle process nothing changes, BUT, if I pull the ram and try to boot, get flasshing power lght, then put the ram back in boots fine.
After doing this will work fine for 2-3 days again sleeping and during use no issues then on the 2nd or 3rd morning back to the start.

I am retesting it now with different ram but if anyone has seen this type of behavior before or has any ideas, I'd much appreciate the input.

 

[futurefear]

Bump

More info , new ram did not help, ran the software update to no avail, seems to only have issues when has been sleeping for 6+ hours or so, I dont have an exact time i just know if it sleeps during the day no issues, if it sleep over night then it has problem.

More info
when coming in in the morning, light is pulsing, upon waking screen does flash on for a moment before going dead. If that helps at all.

other info
Yesterday morning when this happend I had had a video up playing when it when to sleep. upon going through the above mention ram resets and power cycles when it did come back on it brought back the browser and video right where it left of.

Other info
I have tried letting it go to sleep from multiple user accounts same problem.



FYI guys ANY help appreciated, my specialty is PC's so this is driving me nuts, I have a feeling its the power supply, but I don't have extra Imac power supply's laying around to test and don't really want to order one just to "test" Anyone know of any other way or can confirm this would be great.