GX Optiplex 760 Green Blinking lights no power info!

Hi again;
This is going to be for the more advanced people and any one that might have a GX 760 Small Form Factor.
I am writing this because after THREE bleeping 760 have just died in the last month. Thats a lot for our campus and I am afraid more will follow. I am writing this to let tech and people know what I found out.
The symptoms:
You come in in the morning  (always seems to happen at night) and the 760 is off. You hit the power button but nothing. You kneel down to look at it and see 2 leds blinking on the bottom bar. Network and HD I think.
Possible Temporary cure.
If this happens with all 3 it has been the power supply. I am not saying this is the only thing but with ours it was PSU. A temp trick that worked on two of them(didn't think to try it on the first one) is the 760 SFF has a PSU test button on the back next to the power plug with a LED light above it. Little black button, Pressing this will test the power supply if green it "should be ok"
Press it and if you are lucky after holding it down for about 20 seconds the computer will stay running and boot up like it should. After doing some research I found it can be other things like the DVD-R driver or hard drive that set this off and just by changing the hd or unplugging the Disk Drive will allow the computer to come on and work normally.
Ours didn't do that so there is that.
If yours does come on back up what you can. The first one that we did this on lasted 3 days and then died again for the last time. The first 2 we have replaced the power supply in and they are working just fine now. This last one we are hoping to get a power supply in before it keels over.
I really hope this helps some one and I hope you have more luck then us but ours died or are more than likely going to to die. If you have some of these watch them. I don't know what causes it because they have been from 3 completely different places. One was a librarian's computer that did internet and scanned books, another a secretary, and the last one was from a classroom where the kids rarely get on the computers. They just go and dell doesn't seem to have a answer for it right now.

I really hope this helps some one out and good luck to you.