dell optiplex 780 cpu problem

[GotchaMika]

i bought two 780 sff motherboards on ebay for a decent price

i had to trim some plastic from the cpu fan header so i could fit my cpu fan connector to it

the pc makes long beeps one after another i wasnt sure if the cpu was on since the fan didnt spin

but i confirmed that after touching the heatsink i have a normal fan and heatsink on it as it didnt come with one

is there any adapters for cpu fan headers?

[Vapare]

https://www.ebay.com/p/1pcs-5-Pin-Dell-Latch-Fan-Connector-to-4-Pin-Fan-Adapter-Convertion-Cable/1865318521

 

Is this what you are looking for? I know OEM motherboards has funky CPU fan power connectors sometimes.

[Vapare]

If you don't care about fan speed curves and noise, you could just get a molex to 3 - 4 pin fan connector cables for pretty cheap.

[SuperCloneRanger]

Dell use a different pinout on there latching connector than the standard fan connector, since you have already modified your mobo to fit a standard fan connector all you have to do is pop the wires out of the fan connector and put them back in the right order. make your wires order the same as connector on left. yellow is white. if you have a 3 pin ignore blue pwm.

 

[GotchaMika]

24 minutes ago, SuperCloneRanger said:

Dell use a different pinout on there latching connector than the standard fan connector, since you have already modified your mobo to fit a standard fan connector all you have to do is pop the wires out of the fan connector and put them back in the right order. make your wires order the same as connector on left. yellow is white. if you have a 3 pin ignore blue pwm.

 

hi thanks both i changed the wires around but im having a hard time finding the front panel pins to power on the system with a screwdriver

[GotchaMika]

found it but its still making a beeping noise and no fans spin

[SuperCloneRanger]

how many beeps

 

[GotchaMika]

4 beeps lasting around 4 to 5 seconds each

[SuperCloneRanger]

Looked up the beep codes for your board 4 beeps appears to be a memory issue;

 

first try re-seating the memory. remove memory, blow out slots,  wipe contacts on memory with dry paper towel.

 

if that does not help then try each stick individually in each slot and if possible try memory in different system and/or try new memory in current system to try and identify issue.

[SuperCloneRanger]

I found the service manual for your board.

 

http://content.etilize.com/User-Manual/1029902242.pdf

[GotchaMika]

2 hours ago, SuperCloneRanger said:

I found the service manual for your board.

 

http://content.etilize.com/User-Manual/1029902242.pdf

thank you both for your replies sorry i couldnt reply my internet went off it was the ram i took it back to the shop and placed my other ram sticks in the slots booted up the only thing now is i need to find a cpu adapter

[SuperCloneRanger]

to fit the cooler to the weird mounting holes?

[GotchaMika]

Just now, SuperCloneRanger said:

to fit the cooler to the weird mounting holes?

yeah right now im using zip ties but it went to crap because my graphics card gets in the way of the cpu a bit do you know how i can put a normal 775 cpu on there without it coming off? and also how to power it up would a 4 pin splitter do the job?

[GotchaMika]

3 minutes ago, GotchaMika said:

yeah right now im using zip ties but it went to crap because my graphics card gets in the way of the cpu a bit do you know how i can put a normal 775 cpu on there without it coming off? and also how to power it up would a 4 pin splitter do the job?

i tried changing the wires around but the cpu fan still doesnt spin?

[asand1]

33 minutes ago, GotchaMika said:

i tried changing the wires around but the cpu fan still doesnt spin?

You swapped pins 1&3? I am running Standard fans on an Optiplex 790 with the pin swap and it runs fine.

http://pinoutguide.com/Motherboard/dell_5pin_4pin_pinout.shtml

 

 

[SuperCloneRanger]

For the cooler i've got a few ideas:

 

use the original cooler 

 

get a square amd style cooler with vertical fins and mount like this:

 

[SuperCloneRanger]

although not recommended thermal adhesive would probably work too, but once applied it is very difficult to remove.

http://www.arcticsilver.com/arctic_silver_thermal_adhesive.htm

 

as for the fan make sure it is wired correctly and make sure your putting it in the right way round the the 2 connectors are a mirror image of each other. if that dosen't work try a different fan

[GotchaMika]

19 hours ago, SuperCloneRanger said:

although not recommended thermal adhesive would probably work too, but once applied it is very difficult to remove.

http://www.arcticsilver.com/arctic_silver_thermal_adhesive.htm

 

as for the fan make sure it is wired correctly and make sure your putting it in the right way round the the 2 connectors are a mirror image of each other. if that dosen't work try a different fan

thanks for the reply i got my cooler on there with a zip tie i bought a dell cpu fan adapter which works but now im facing problems with my new ram i just bought today

they are two 4gb sticks i tried changing the clock speed to 1066 insteac of 1600 but nothing is working? im getting beeps

[SuperCloneRanger]

EDITED

[SuperCloneRanger]

i've looked at the specs for you board and the 8 gb should work, the speed should not be an issue, the board should automaticly set the speed to 1066. first make sure your using the correct dimm slots, looking at the manual it is the white ones. then reset the cmos:

 

disconnect form wall

Remove coin cell battery from holder

Press the power button for at least 10 seconds

Re-insert coin cell battery

When the system is powered on, it will warn that the date and time is not set, indicating a successful reset.

 

also here is the correct manual for your board, not sure why google gave the the 760 docs when i asked for 780.

http://downloads.dell.com/manuals/all-products/esuprt_desktop/esuprt_optiplex_desktop/optiplex-780_service manual3_en-us.pdf

[GotchaMika]

On 11/18/2017 at 1:02 AM, SuperCloneRanger said:

i've looked at the specs for you board and the 8 gb should work, the speed should not be an issue, the board should automaticly set the speed to 1066. first make sure your using the correct dimm slots, looking at the manual it is the white ones. then reset the cmos:

 

disconnect form wall

Remove coin cell battery from holder

Press the power button for at least 10 seconds

Re-insert coin cell battery

When the system is powered on, it will warn that the date and time is not set, indicating a successful reset.

 

also here is the correct manual for your board, not sure why google gave the the 760 docs when i asked for 780.

http://downloads.dell.com/manuals/all-products/esuprt_desktop/esuprt_optiplex_desktop/optiplex-780_service manual3_en-us.pdf

i dont have white dim slots? they are all black?

[GotchaMika]

sorry for the last reply i now see what you mean i tried them in the white dim slots and same beeps? 

[GotchaMika]

9 minutes ago, GotchaMika said:

sorry for the last reply i now see what you mean i tried them in the white dim slots and same beeps? 

i read that it only supports low density ram? im trying to use hyperx savage ram

[SuperCloneRanger]

i've not thought about memory density in a long time, but looking at this info i found on the dell forum you're right.

http://en.community.dell.com/support-forums/desktop/f/3514/t/19629648

 

your best be is to look for 780 specific memory or add low density when searching ebay/amazon. your unlikely to find this memory new as no one will be making it anymore. who knew it would be such pain to get a cheap dell board working.

[GotchaMika]

2 hours ago, SuperCloneRanger said:

i've not thought about memory density in a long time, but looking at this info i found on the dell forum you're right.

http://en.community.dell.com/support-forums/desktop/f/3514/t/19629648

 

your best be is to look for 780 specific memory or add low density when searching ebay/amazon. your unlikely to find this memory new as no one will be making it anymore. who knew it would be such pain to get a cheap dell board working.

i ordered 8gb of ram from ebay i think its low density it hasnt got any heatsinks so it should work hopefully it should be here tomorrow ill let you know if its all up and running

on a good note atleast my main rig will have 24gb of ram instead of 16 thats a plus