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Optiplex 760 DT CPU upgrade fail
I decided to upgrade the CPU on my Optiplex 760 DT from a C2D E8400 to a C2Q Q8400. But then when I did it, diagnostics 3 and 4 blinked, and the power button was orange. I tried removing the ram and putting it back in. Still the same thing. When I put the old e8400 back in, diagnostic lights 2 3 and 4 started blinking, and power button was yellow. Anybody can help?
WM1000
20 Posts
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March 10th, 2018 14:00
WM1000
20 Posts
0
March 10th, 2018 19:00
My bios is updated to the latest
elpro999dell
367 Posts
1
March 11th, 2018 20:00
The Optiplex 760 uses two motherboards -
T674K Non-Quad core CPU motherboard
U562N Quad core CPU motherboard
Look on the motherboard near the PCI-E 16x slot there is a little sticker that says the motherboard P/N if it is the one "T674K " then that's why it won't boot. If it is the other one try reseating the CPU should boot after that.
WM1000
20 Posts
0
March 12th, 2018 14:00
The motherboard is a 0R230R. I also tried an E8600 and it wouldn't boot properly, so it was still a 2-3-4 diagnostic code
elpro999dell
367 Posts
0
March 12th, 2018 15:00
BIOS is dead that's why the CPU change did nothing. Unfortunately you have to replace the motherboard as it is now in "Bricked" state.
WM1000
20 Posts
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March 13th, 2018 15:00
Um. so I could kill a BIOS just from replacing a processor?
elpro999dell
367 Posts
0
March 17th, 2018 20:00
I do not think the CPU swap did such thing. Try reconnecting the hard drive cables another user had success when a similar issue occurred.
https://www.dell.com/community/Desktops-General/Optiplex-760-diagnostic-lights-2-3-4-blinking-and-solid-amber/m-p/5121053
WM1000
20 Posts
0
March 25th, 2018 16:00
I found out that I didn't install the CPU correctly. Today, I installed the CPU again correctly after watching "How to install LGA 775 CPU" videos, I got the Optiplex 760 working with the Q8400, and that actually solved the problem.
jdubbu
5 Posts
0
November 23rd, 2020 14:00
I'm looking at moving up to a Quad on the same motherboard....0R230R. Did the Q8400 work long term? Are all 4 cores operating? I can't seem to find much info on the 0R230R motherboard capabilities and sometimes the capabilities can be exceeded.
WM1000
20 Posts
0
December 13th, 2020 14:00
I do not have this system anymore but for me the Q8400 worked okay with all cores enable, most if not all C2Q's should work too.