Studio XPS 9100 Not Powering on after power failure

Try clear cmos settings via motherboard jumper.

@redxps630​ Done that each time I pull the cmos battery before popping it back in

A power supply unit from 2011 may be a "little long in the tooth". Might be worth your while to test it after clearing CMOS settings as recommended by redxps630.

Best of luck.

It gives an impression that in your area power possibly goes out more often than normally expected.  When this happens, was the pc in a shut down and powered off state, or actively on?  If the latter, it is unhealthy to the pc, and you should consider investing in a battery UPS.

if the former,

Try simulate a power down situation by shutting down the pc completely then unplugging power cord, or turning off power on a power strip.  Press the power button to drain all flea power.  Then plug in power cord again and press the power button.  If the pc is able to power up normally, then it is behaving well during a normal power on/off event.  Then the unexpected power down event might have a surge, try a surge protector.

@smokeygraypoupon​ Brand New PSU 850W and pulled  the video card out and still will not power up till the battery is reset. I am stumped.

@redxps630​ Went through the testing from the OSU testing on Dell's site .  Usually not that many power interruption or outages unless it is storming but the PC was never in an on state when the power went out. I even tried to simulate a sudden power outage after I had reset the battery and got the pc to power on and boot up by plugging the plug and then going through the steps to drain the residual power but still, until the cmos battery is popped out and back in this thing just won't power on.

Hate to buy a new board, hard to find new and just don't trust buying a used one. But may have to unless a Dell Tech can figure this out. I even pulled the board to check the soldier on the back of the battery socket to the board and looks good but then I an no expert on soldiering

It is not worth buying a new replacement board for this x58 chipset intel 1st gen pc.  People who still buy/sell x58 board are enthusiasts not common users.

if the power outage is infrequent then I would just turn off power strip completely after you are done using it every day and shut it down, so it is completely off power.  If the next day you can reliably power it on despite interval power outage episodes then it is a solution.

if problem persist, replace it with an updated intel gen Dell or third party standard mATX board, if you like the case and want to continue using it.  I put an ASUS i7-3770 board in XPS 9100 works fine.  The only downside is losing the proprietary Dell front led board light.

Just want to add a suggestion here.  It's not feasible to replace the motherboard.  Instead, set Power Options to Power Saver mode (in Control Panel) and leave the PC always powered on.  It will go into sleep mode while not in use and will providing an instant power on as needed.  An occasionally shutdown may still be required but that should reduce the number of times for battery reset significantly.

@Chino de Oro​ That will do nothing for a power outage as the problem only happens when the power is disconnected either by a power outage or unplugging the pc to move it. When power is restored it will not power on at all until the cmos battery is popped out and put back in then it will power on.

That still beats the frequent of times you must reseat the battery each time you want to use the computer.  Unless you can think of a better NO COST solution.