On 12/30/18 4:22 AM, Kumonie Williams wrote:
Upon further inspection, I cannot find any reference to the SERVICE_MODE jumper on Dell's website, only the two you mentioned, RTCRST and PSWD. It appears it may only be present on the mid tower form factor model of the Dell OptiPlex 7010, on which, it is directly under the PCI-e x16 (wired as x4) slot, to the left of INT_USB. A photo with the jumper circled in yellow has been made available for clarity here: https://imgur.com/a/Bn0yuin
My board definitely looks different in area of SPI flashes. It seems like Dell OptiPlex 7010 had various little bit different designs - service mode jumper  and different PCB layout around SPI flashes .
There is seem to be different revisions of this mainboard.
I heard from a post on a public forum (https://www.bios-mods.com/forum/Thread-PSA-Dell-Service-Mode-jumper-on-Optip...) that the service mode jumper would allow you to use an "auxiliary BIOS" in case the "BIOS flash" (assumed they meant the chip with the firmware on it) was damaged, however, after Jeremy's comment on the matter, I believe either that post was incorrect, or the "auxiliary" BIOS is on a different region of the same chip.
It looks like much better explanation is on win-raid forum , but thread is pretty long and I didn't digest all information there.
I'm still looks for advise how this SPI was flashed, I suspect internal programmer since both paths on gerrit have 12MB and SPI1_1 has just 4MB. Also it looks like doesn't contain full BIOS but just part of it. For those interested in helping binary from SPI1_1 .
 https://www.instagram.com/p/BsA6eeQFfaw/?utm_source=ig_web_button_share_shee...  https://www.instagram.com/p/BsA7zX3FxzT/?utm_source=ig_web_button_share_shee...  https://www.win-raid.com/t1053f39-Optiplex-and-VPro-AMT-ME.html#msg18356  https://cloud.3mdeb.com/index.php/s/XxyRfeKRxWNTJ7P