Dell optiplex 760 q8400 not booting

Question

Hello

I upgraded my dell optiplex 760 with a q8400 and it does not boot, seems to be some sort of boot loop. Lights 1 3 and 4 are lit and the pc powers up and shuts down. I have tried reseating the q8400 with no luck and replaced it with the old Pentium and it booted.

Thanks for any help

bradthetechnut · Accepted Answer

Dell Diagnostic Indicators In case needed for reference, 760 goes back to 2009.

Below is what Dell Diagnostics had to say and I wanted to present the options. I also still think your Q8400 might be faulty as fault only occured with it installed.

1 34

PRV

Indicates system activity preceding video initialization

Remove all external peripherals and any internal CRUs
If LEDs change, add parts back one at a time until fault re-occurs and contact your technical support
If the fault remains the same with parts removed, contact your technical support

Mary G · Answer

You answered your implied question. You cannot change the cpu. The motherboard dictates what cpu you can use. In that 11 yr old computer it is not practical to try and change the cpu. You are limited to a cpu that would not add much if anything to performance. Save the money for a new computer.

John Connelly · Answer

You can in fact change the cpu, I've done my research to find a good cpu for this pc. This pc also isn't for me, it's for a friend, I have a pretty good rig already.

redxps630 · Answer

.

John Connelly · Answer

That's what i have been wondering as the error code 1 3 4 is not on dell's manual so it's never really been seen before. If I can't get it working I'll message the seller and request for a new one or even a refund

bradthetechnut · Answer

Optiplex 760 Tech Guide  Well, the Q8400 is skipped in the Tech Guide.  But I found a couple of other Dell Community posts and it looks like it should work granted it isn't faulty.

redxps630 · Answer

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speedstep · Answer

There are multiple revisions of 760 board. Usff do not support quads. Intel Q43 Express Chipset w/ICH10D

https://www.dell.com/community/Desktops-General-Read-Only/CPU-upgrade-for-Optiplex-760/td-p/3694138

Not all versions support Quad core cpus.

The Optiplex 760MT uses two motherboards -
T674K Non-Quad core CPU motherboard
U562N Quad core CPU motherboard

You have the 1st one so you cannot use a quad core CPU on it.

38G73 E7400, 2.8GHz, 3MB, WFD, R0, (With VT)
F31F5 E7500, 2.93GHz, 3MB, WFD, R0, (With VT)
06YMG Wolfdale Dual Core E7600, 3.06GHz, 3MB, 65W, R0, (With VT)
H399J Wolfdale Dual Core E8400, 3.0GHz, 6MB, 65W, E0, 1333FSB
D923J Wolfdale Dual Core E8500, 3.16GHz, 6MB, 65W, E0, 1333FSB
N654J Wolfdale Processor E8600, 3.33GHz

M858N OptiPlex 760 MT LGA 775 Socket T

Fastest supported CPU on NON USFF is

Intel® Core™ 2 Quad Q9650/3.00GHz, 12M, 1333FSB

https://www.amazon.com/Intel-Q9650-Processor-Socket-LGA775/dp/B001D86S3G

https://www.dell.com/downloads/ap/products/optix/optix_760_tech_guide.pdf

	Intel Core2 Quad	Intel Core2 Duo	Intel Pentium Dual-Core
Model	Q9550 Q9650 Q9400 Q8300 Q8200	E8600 E8500 E8400 E8300	E7300 E7200	E6550	E4700	E2220 E2200
Cores	4	2	2	2	2	2
FSB speed	1333 MHz	1333 MHz	1066 MHz	1333 MHz	800 MHz	800 MHz
L2 Cache size	12 MB 4 MB	6 MB	3 MB	4 MB	2 MB	1 MB

760 Family

John Connelly · Answer

Hi @bradthetechnut

I Have the optiplex 760 my, and don't worry I made sure that the motherboard was the right model as I done the research before I started upgrading. I'm a bit of a tech guy myself as I have built a gaming PC and this project was for a friend. The only reason I posted in these forums is due to this being the first time I've worked with a pre build office pc and couldn't for the life of me find out what the issue was. Your post helped me out a lot and I got in contact with the seller and they are now sending out another.

Thanks for the help.

John

bradthetechnut · Answer

Hi @John Connelly, Thank you for accepting my post as a solution.  I forgot to ask - What size is your 760?  Just the USFF doesn't support quads.

John Connelly · Answer

@speedstep how do you know my mobo isn't compatible when you haven't even got me to check to see if it is the right one. The sticker beside the pcie slot says that's the model is 0R230R and cpuz also says that.

speedstep · Answer

0R230R  is not Mini Tower its desktop board.

John Connelly · Answer

@speedstep sorry I mistook my optiplex for the mt

Optiplex Desktops

Dell optiplex 760 q8400 not booting

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