Dell OptiPlex 9020 SFF
system won't show screen, power led is white, cpu fan revs, but not loudly.
Dell Support were friendly & helpful but didn't get me anywhere, so it's DIY :-).
Power supply test (button on PSU) runs OK when turned off and PSU led is green, so not a power supply problem.
Shutdown and remove power for 1min - no change.
Disconnect HDD, AMD graphics card & DVD & one (of 2) memory module- no change.
Remove both DIMM, pwr on - system beeps - good motherboard is alive :-)
Disconnect power, remove last Memory DIMM & swap for the other one & system boots into BIOS Menu (as there's no disks to boot from)
Pwr down, connect HDD - Pwr up -no screen, no boot. (After this you're back to a dead PC agian)
Long story short - ONLY if you change the DIMM & leave ONE DIMM by itself THEN will system start, but not if any disks are connected. (if you only have one DIMM use Slot2 which works)
Download Dell BIOS Updater & Create Boot Disk - here (you can copy the URL, just delete the spaces)
http:// www. dell.com/support/article/us/en/19/SLN143196/EN
http:// www. dell.com/support/article/us/en/19/SLN284433/en#How_to_update_USB_flash_drive
BIOS file Here
http:// www. dell.com/support/home/us/en/19/Drivers/DriversDetails?driverId=N08H6&fileId=3542449770&osCode=W764&productCode=optiplex-9020-desktop&languageCode=en&categoryId=BI
In BIOS Menu, Disable SecureBoot, Change BIOS BOOT to Legacy
Run BIOS update from USB
Boot from usb & type BIOS package name o9020a16.exe, enter & you'll be updated to latest version
DON'T POWER OFF - the updater will restart by itself!
In BIOS Menu, Change Boot to UEFI, enable SecureBoot (if you don't you can have startup problems)
Connect HDD & other components & you should be good to go!
I know it's been a while since this was posted, but I had the exact problem you were having. This post has saved me.
Thank you so much for taking the time to post a solution, not just a problem! Hopefully others with this issue will find this great guide and get their computer running again.
Thank you for the reply & glad that my (rather long) post helped. I hope others find it helpful as well.
I had same issue.
I swapped out DIMMs and problem solved. Thanks for this post as it really sped up my troubleshooting!
Did your errant unit also emit a single beep while attempting to boot? When you mentioned the fan quietly revving it sounded similar to my issue; the unit continuously cycling on momentarily which gets the cpu fan going for a sec, followed by a beep then the unit shuts off. If I leave it connected to a power source it will repeat this cycle endlessly. Did your 9020 mimick these same symptoms?
I can't remember my unit beeping whilst trying to boot (I think I'd have mentioned it in my post :-) )
I've just rebooted my Opti9020 and it doesn't beep at all, so sorry to be of little help.
I see that Dell have eliminated all Power on beep code except "No memory failure" which is 1-3-2 beeps - see here
"Note: Starting from the D4 generation of OptiPlex models onwards (i.e. 7010/9010/9010 AIO), the beep codes will be eliminated, replaced by a single memory error pattern. Now only no memory failure conditions generate the beep code, the beep pattern is 1-3-2 (1 beep, then 3 beeps, then 2 beeps). This beep code tells you that the computer encountered a memory problem. The new beep codes emit only memory failure symptoms. Occasionally, reseating the memory modules may fix the beep code errors."
Good luck & IHTH