After adding new ram won't boot

[MDNO]

Hi!
I have HP Compaq dc5800 microtower pc with Windows technical preview 64-bit (Windows 10).
Memory type: DDR2 800mhz 240-pin DIMM
I don't have any idea what is my PCs motherboard but I checked PC specs from HPs site and there it said this PC has possibility to upgrade to max. 8gb.
I bought new 2x4gb ram and when I install them and try to boot, it wont even open the bios screen and monitor stays all black and after few seconds fans starts to spin very loudly.
I've tried to clear CMOS many times, cleaned ram seats(4 seats) with air and have tried many combinations with the rams on the seats but nothing seems to help.
When I installed original rams (2x1gb) and one 4gb ram to 3th place my pc booted and at the settings it said "6gb installed, 2gb usable".
Could someone help?

 

[rolli59]

Have you tried only with the new ram after resetting BIOS with it in?

According to this you can only use 4 x 4GB modules http://www8.hp.com/h20195/v2/GetDocument.aspx?docname=c04290830

 

[MDNO]

Yes. When cleared CMOS and installed new rams I plugged power cable and vga. It automaticly boots and shuts down fast. Then I started to boot it the same thing happened: monitor blank, fans spins loudly.

 

[faalin]

maximum allowed ram for the board is 8gb so 4x2GB sticks is the max, the highest stick allowed is 2048MB-800MHz DDR2-800 PC2-6400, 240p DIMM, 1.8v

http://www.memoryupgradecompany.com/memory/HPCompaqdc5800MicrotowerMemoryUpgrade.html

 

[rolli59]

Look at the link I posted above and make sure your BIOS is up to date.

 

[rolli59]

maximum allowed ram for the board is 8gb so 4x2GB sticks is the max, the highest stick allowed is 2048MB-800MHz DDR2-800 PC2-6400, 240p DIMM, 1.8v

4 x4GB is listed http://www8.hp.com/h20195/v2/GetDocument.aspx?docname=c04290830

 

[faalin]

maximum allowed ram for the board is 8gb so 4x2GB sticks is the max, the highest stick allowed is 2048MB-800MHz DDR2-800 PC2-6400, 240p DIMM, 1.8v

4 x4GB is listed http://www8.hp.com/h20195/v2/GetDocument.aspx?docname=c04290830

that's for a business computer not a microtower that he posted. also the max allowed on a Q33 chipset is 8GB

That's why when he puts his 2x1Gb and a 4gb stick in it sees all 6gb but only allows 2gb to be used. the chipset knows its there but cant use it.

 

[MDNO]

Oh damn. So I if want to 8gb ram I have to install 4x2gb and if I want to install 16gb it has to be 4x4gb? Okay.
Thanks for the help !!

 

[faalin]

Oh damn. So I if want to 8gb ram I have to install 4x2gb and if I want to install 16gb it has to be 4x4gb? Okay.
Thanks for the help !!

no the highest you can go is 8Gb on that board. The max the computer will handle is 4x2GB sticks for a total of 8GB no more. The Q33chipset will not allow more then 8GB. That's why the 4GB sticks you have now will not load up the computer.

 

[rolli59]

maximum allowed ram for the board is 8gb so 4x2GB sticks is the max, the highest stick allowed is 2048MB-800MHz DDR2-800 PC2-6400, 240p DIMM, 1.8v

4 x4GB is listed http://www8.hp.com/h20195/v2/GetDocument.aspx?docname=c04290830

that's for a business computer not a microtower that he posted. also the max allowed on a Q33 chipset is 8GB

That's why when he puts his 2x1Gb and a 4gb stick in it sees all 6gb but only allows 2gb to be used. the chipset knows its there but cant use it.

HP Compaq dc5800c small form factor = microtower and is Q33 chipset! So the info is correct!
OP most likely there is a BIOS update to allow for the 4 x 4GB!