Inspiron 5680 Powers On for Only A Few Seconds - Unable to Diagnose Issue

Sounds -to me- like it may be overheating....

Do you clean the thermal paste off top of the CPU and bottom of heat sink each time, and then apply a thin, fresh coat of thermal paste before reattaching the heat sink? 

And are you sure the CPU fan is properly plugged into the correct fan header on the motherboard?

And how old is the motherboard battery?  With all your work inside the case, the battery may have died and BIOS settings could have gotten scrambled.  So remove (old) battery and press/hold power button on PC for ~30 sec. Then install the fresh one, as last step before closing the case...

@RoHe​ ,

Thank you for your reply.   

Yes, cleaned the thermal paste...  It was a hassle...  Also replaced the battery.  Light bar and logo illuminated and all three fans worked; CPU, case and GPU.  All are in proper sockets.  

Read somewhere the EVGA 700 BR did not work in a 5680.  I'm new to PSU change outs so don't know why a PSU is not just a PSU.  Does Dell have proprietary PSUs and using a non-Dell will cause a motherboard failure.

Do you know of any aftermarket PSUs that are proven to work in a 5680?

I'll try again tomorrow.

Al

@SaadAliSyed​ ,

Thanks for the step-by-step!  I'll see what comes of it and let you know.

As I mentioned to @RoHe , I don't understand how a PSU can be incompatible.  I checked the output voltages of the EVGA against the Dell and they are identical. 

Thanks again,

Al

Regards,

Al

"If it powers on and works, your new PSU might be defective or incompatible."  This is what happens when blindly pasting from AI bot.

Try replacing the battery as RoHe suggested.  Then give BIOS a hard reset via jumper on MB.  Battery replacement is just a soft reset.  How to Perform a BIOS or CMOS Reset and Clear the NVRAM on Dell Computers

Did you put the RAM back to it's original configuration also?

When upgrading, it's best not to do a whole bunch of things at once, but do one at time and see if PC boots after each one.

@Acesar_82​  I think you already know PSU's aren't a single spec of watts or volts as suggested by another.  Double-check the 3.3v/5v rails.  Does the new EVGA PSU have as much power, if not more, than the OEM PSU?

Aftermarket PSU's can boast more total power, but then skimp on the 3.3v/5v rails, and then it doesn't work in a Dell.

Hi @RoHe  How good is your memory?  Wasn't it a 5680 (or very similar) that wouldn't work with an aftermarket PSU in another thread, and then, after my lead and per your suggestion, went with a Dell OEM 850w PSU that comes with another model, and then it worked?

@JOcean​ ,

Thanks to you and all for your comments.  I have no idea how, but it's looking like the motherboard was damaged during the upgrade.  The unit should have worked after all original components were reinstalled.   

I'll double check the pins but I think my best bet if that doesn't work is to replace the motherboard.  

Anyone have a part number for the Dell 850 PSU?

Al

@bradthetechnut​ ,

The EVGA PSU is rated at 700W - more power than the OEM. 

Since the unit doesn't work when all OEM components were reinstalled, I think as many have suggested, the motherboard is damaged.

Thank you.

@bradthetechnut​ ,

Yea, I thought of doing one upgrade at a time after the fact.  DOH!!

@Acesar_82​  It wasn't the 700w total power I was concerned about, but power on the 3.3v/5v rails.  Normally with other Dell PC models, the EVGA you got would be more than enough, but the Inspiron 5680 may be a different breed.  The EVGA BR 700w PSU has 150w on those rails.  But what if the 5680 requires more?  I take it that it's the BR model PSU you got?  Some other EVGA 700w PSU's have less power on those rails.

You were right that you probably read somewhere that the EVGA PSU does not work with the 5680.

With all original components reinstalled, including RAM and CPU, I'm in agreement with the other Rockstars that the MB may have been damaged, as you were thinking also.

I think @RoHe had the part number for the 850w Dell PSU.  @redxps630 may be able to find it as well.  He's been a PSU master.

@Acesar_82​  Also, per JOcean's suggestion, double-check CPU socket pins with a magnifying glass.

@JOcean​ ,

Double-checked and the issue is......... bent pins.

Uuuuuuuuuuuuugh.

Time to buy a new MB...

Thanks for all the help...