Elitedesk 800 G1 DM - Fans running at full speed

[STUKguy]

Hi,

So for some idiotic reason i thought any 1150 cpu would work fine in a G1 800 so brought a Xeon and put it into my machine and it would not boot just after about 20 secounds the fans turned on a blew at full speed nothing else, i let this run for about 5 mintues just to see if it changes but nothing happend.

I then plugged in a monitor and keyboard to see what was going on but nothing came up on the screen, i tried several reboot to try and jump into the BIOS but it wouldnt even let me go that far. i tried putting back in the orignal I5 but still the same thing.

I did post my issue on another forum and they suggested that the xeon must have messed up the BIOs and i would need a CM cable to reflash the BIOs, which sounded a bit to difficult for me so insted i bidded on 2 G1 800 motherboards and ended up winning both bids, when both motherboards turned up  i couldnt find my i5 cpu so i put in a i3 (i think the G1 orignally came with) but the same thing on 2 diffrent motherboards brought from 2 differant sellers no display out put and fans blow at full power after about 20 seconds.

I have tried diffrant RAM sticks, differant power outlets, clearing the CMOS, changing the CMOS battery, tried boot with out the SSD plugged in.

I am very confused please can someone help me?

[DGroves]

the  Elitedesk 800 G1 uses 4th gen xeons and core 3/5/7 cpu's

assuming you are install the correct gen cpu and that the ram/motherboard power connections  are correct

you then need to determine if the cpu installed has onboard video (if so no external video card is required)

if your cpu lacks onboard video, or you insert a discrete video card then the onboard video cpu based video is disabled

and you connect the monitor to the discrete video card instead of motherboard video out connector

now do a cmos reset by disconnecting power to the system and then remove the cmos battery for 5min and reinstall

reconnect the power cord and power on then WAIT SEVERAL MINUTES (up to 5min)............... the system needs to detect all hardware installed (including the changed/different cpu installed) and this takes time, note the system may start/stop then start again before the normal display boot screen appears

[STUKguy]

Thank you for your reply, it was a Xeon E3-1220 V3 i have returned it now and trying to go back to the i% i had working in the machine before all this happend.

I tried what you suggested but unfortunatly even after 10 minutes all that happened was the fan running at full speed, i placed one of the other motherboards i had just incase, it worked powered it on & off serveral times just to be sure but turned on fine each time but strangly it wouldnt boot from the SSD. So i am currently in the process's of rebuilding my OS and i will try and return the other motherboard i accidently bid on.

Thank you for your help.