XPS 8300 won't boot, no post, no beeps, no display

What color is power button and is it steady or blinking when PC won't boot?

What happens if you put the original Asus Nvidia GeForce GT 720  back in?

Did you change video port type being used on new video card or with onboard graphics vs the port type you used with old video card? Do you have to re-configure the monitor on its own menu, if you changed port type?

EDIT: Did you check the PSU LED on back of PC right below the power cord socket?

(1) Power button has been white when powered on, but i just did a long press on it and now it only indicates yellow.

(2) removing card, reinstalling/reseating graphics card made no difference.

(3)  had to replace my original Dell PSU some time ago, currently Corsair RM650x, so no LED on it, but fan on PSU runs at power up then stops

clarification:  by 'display', i mean my external display which was originally attached to the 8300, not laptop display...

(4) no, i did not change video port type

NOTE:  Display working fine on my laptop

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@PB Weston wrote:

1. Have removed current graphics card (Asus Nvidia GeForce GT 720) which was working fine,

2. Just replaced motherboard, same symptoms:  no boot / no display.

Can someone please help?

 

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1. That was your first mistake (just kidding).

2. "It's dead Jim" . Man, I'm really funny tonight ...

But seriously, try the Nvidia card with most basic hardware config. You can check Power-Supply with Digital Power Supply Tester. If you swapped MB, recheck all steps and parts you moved-over.

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@PB Weston wrote:

(1) Power button has been white when powered on, but i just did a long press on it and now it only indicates yellow.

(2) removing card, reinstalling/reseating graphics card made no difference.

(3)  had to replace my original Dell PSU some time ago, currently Corsair RM650x, so no LED on it, but fan on PSU runs at power up then stops

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When was last time you replaced motherboard battery? I'd do that now. After removing old battery, press/hold power button on PC for ~30 sec before installing a new one.

Is power button steady amber or blinking?

"Reinstalling/reseating"  - Is that the original video card which was working?

If this is happening with 2 motherboards, assuming at least one of them works, that suggests the problem is with some other component, eg: PSU, front panel cable connections, front power button, cable connection(s) to motherboard, RAM etc...

@PB Weston 

Basics.  Bad power supply.

Remove everything including  cards.

Disconnect hard drive data cable

Remove all ram

Turn on it should beep beep beep beep low and slow.

put 1 ram stick in beep pattern should change

put 1 video card in it should say no boot device on screen

re attach hard drive if it then crashes to black screen of death HDD is dead.  Attach new blank hdd and install windows clean.

thanks did as you suggested but NO beeps!

just tried a new PSU, didn't help either

ROTFLMAO (not!)

The problem occurred BEFORE replacing MB.  Have replaced PSU now as well, and all cards removed, inserted back one by one, ditto DIMM's etc.  Yes, all steps/items rigorously double checked, (30 yr I.T. vet, not a neophyte). Without sound nor video unable to see/hear any beeps, warnings, prompts, etc have replaced/ugraded almost everything except processor.

installed fresh new battery when i replaced motherboard.

onboard graphics not producing signal, nor is either of my two graphics cards (all of which WERE working before)

without video/sound cannot see/hear anything to help diagnose

system had been working fine for 10yrs

i think i have eliminated almost everything other than power button & processor, but power button DOES turn the fans on, it's basically on or not on, right?  

Frustrating! 

PB

just replaced PSU - didn't make any difference either

also tried original memory dimm's, even empy DIMM slots, still no video, no beeps, nothing just cpu fan & chassis fan running and m/b aux pwr rp4 LED on

Sounds like you've ruled out just about everything except the front I/O panel and the CPU...

Only you can decide how much more time and $ to invest in trying to fix it vs sending it to the PC boneyard.

Thanks Ron, really appreciate your time.

I've been hoping to avoid the processor replacement but have one question left before i consider that:  what precisely do you mean by front I/O panel?  on the XPS 8300 does that mean the TOP I/O Panel?  It has 2x USB ports, a MIC jack & a EARPHONE jack?   If that has somehow failed, there are equivalent ports on the rear, would that really cause a boot failure?

Or, do you mean the Front Memory Card slots (4x)?   

Thx. 

PB

XPS 8300 Top I/O Panel

Under normal circumstances i would have sent this beast to the PC boneyard & upgraded as i have done many times in the past, but as a retired dude on fixed income just ain't gonna happen any time soon. a processor replacement is within my budget, a new comparable PC simply isn't unfortunately. i've upgraded the 8300 to 32Gb, switched to SSD, upgraded graphics, etc and has been humming along nicely until this catastrophy.  i've been using a backup laptop in the meantime which grunts & groans & painfully plods along.  So either i give up on the 8300 or i give it one more (albeit expensive & risky) kick at the can.  something to think about, i'm aware of the folly trying to extend an old machine.  

once again my profoundest thanks for your time and advice!

PB

There are multiple connectors between the motherboard and the front and top panels, including power button, USB , audio, card reader, etc. And there may be a small circuit board inside the front panel too. So a failure in any one of them...

BTW: There are two power connectors shown on the motherboard diagram, PWR1 and PWR2. Are you sure both of them, plus the two fan connectors, CPU_FAN and SYS-FAN 1, are all properly connected?

Are you sure the 'new' motherboard actually works?

Is it worth the money to try a new CPU, especially if there's no guarantee it solves the problem,  given the age of this system?

You're welcome. Sorry we couldn't you help fix the problem.

Post back and let us know if you get this one working again...