I have had the same problem for over a year, usually can get the computer to come up within 30 minutes of playing with it. I bought a new computer as I did not feel the need to replace components, when there was no definitive solution. I replaced this computer with my new one in my spare bedroom/office. I put the XPS 730 in our dining room and hooked it up as there was a few items I still needed to get off of the hard drive. It immediately powered up, in fact it has been powering up without fail for over two almost three weeks. That's with me checking it morning, midday and night, it has been powering up without fail...
So what if I put it back where it was, would it still work? Nope, fails constantly, then will after much playing with it, I can get it to post. Back to the dining room, works every time.
Back to the old place, it still fails, removed power strip and plugged directly into the wall, still fails. Get out the meter, and checked the voltage. In the Dining room where it has always worked voltage is always 122v or higher.
Back to the old location, voltage is 121v, and it fails to post. Turn off radio, lights, printer and anything else that might be on, the voltage is 122v. The XPS has posted everytime. This leads me to suspect aging of components in power supply or maybe I should replace the circuit breaker to the bedroom.
Just to add to the confusion. I hooked up a meter to the circuit in the bedroom. The voltage normally fluctuates between 118v and 124v. I understand that voltage fluctuations are normal for power provided by utilities. When the lights, radio and etc are on, I wait for the meter to show a higher voltage in the bedroom, it will power up. Conversely, when it is 121 or lower it will not post. This might explain the randomness of it working and failing.
I still do not know what the exact problem is, but maybe somebody can see if this applies to their situation.
