PC doesn't power up,no fan movement.

[venery]

Hi everyone,
So yesterday I bought a new psu Corsair CX750 to hopefully fix my pc overheating issues and connected it to my
As rock mobo.
When I installed a 2nd Hdd and powered on,the fans spinned a bit and all stopped.
Powered on again,same issue.3rd time all fans stopped booting.
I get no sound from my motherboard,tho i've tried the speaker on a different motherboard and it won't beep either.

So I have a
mobo:AS Rock 970 r.20/Gygabyte 970 a d3
Amd fx4100-3.6 ghz
4 gb A-data 1330 mhz ddr3/kingmax ddr3 1600mhz
Saphire Radeon 5770 HD/radeon 4670
Corsair CX750-750W/sirtec 400w
M4-Crucial 120gb/WD 200 Gb

Both mobos were working fine

So on my as rock mobo,with the cpu,each gpu and memory stick at a time and each psu, nothing happens when I power it on,(no boot,the fans won't start)I checked the power cables,replaced all cables,
removed it from the case and tried starting it on a box,that didn't help either.

On my gygabyte mobo,trying each component at a time,the best I can get is a few mseconds of fan movement
every once in a while.

Then I jump started all psu's with a paperclip and conected to some case fans,and the fans spin.
I tried the sirtec 400 w on my brother's pc and that works too.(His mobo has only 4 cpu power pins so I
couldn't try the corsair)

I tried all my gpus/ram/hdds on my brother's pc and all work fine.

I have an am3+ socket on the mobo and a am3+ cpu so I can't try the cpu on his mobo cuz his is
am2/am3.

I tried his CPU an Athlon Xii 2x on my mobos,and it didn't work either(The manufacturer site says they
are compatible but the site where I bought it from says it's only compatible with the Xii 3X 4X and so on,nothing
about the Xii 2x) Also his cpu was full of dust,yet it works on his rig.

I also pulled out the cmos battery on both my mobos.

My cpu looks brand new(except for the thermal compound) all pins look ok,tried a credit card to see if they're equal
,my as rock mobo is brand new and the gygabyte was working just fine a month ago before I installed the new one.

Can a Cpu be fried without the smell or look?And would that stop my pc from powering up?
Or is it the mobo?

 

[HEXiT]

try your old psu, if its not broken it will tell you if the 750w is.

 

[venery]

try your old psu, if its not broken it will tell you if the 750w is.

I tried the old psu on both my mobos,it doesn't work,yesterday both psus were working fine,
i tried the old psu on my brother's rig,it works fine.

 

[lonewolf7]

I think the MB is dead.

 

[mauller07]

try changing the cmos battery first on the non working mobo.

 

[venery]

I think the MB is dead.

I am considering that,but why would both be dead?
When both ran just fine untill yesterday.

 

[venery]

try changing the cmos battery first on the non working mobo.

Just tried,still no fan movement or power up.

 

[mauller07]

did you use the battery from a working computer?

 

[Tom Tancredi]

You had powered it with 400W PSU, you added new hardware needing more power then experianced a problem with it powered in. You 'tested' it by swapping to another 400W, that is where I think your logicial process failed. You should use a HIGHER power supply then 400W, (like 500-650W) and see if the system suddenly (in that configuration with second drive) works now. If not could be you caused static electricity / shorted the board and fried some caps / board components and it is dead. Either case, 400W is normally NOT recommended these days due to the hardware demands.

 

[venery]

did you use the battery from a working computer?

Yes I did.

You had powered it with 400W PSU, you added new hardware needing more power then experianced a problem with it powered in. You 'tested' it by swapping to another 400W, that is where I think your logicial process failed. You should use a HIGHER power supply then 400W, (like 500-650W) and see if the system suddenly (in that configuration with second drive) works now. If not could be you caused static electricity / shorted the board and fried some caps / board components and it is dead. Either case, 400W is normally NOT recommended these days due to the hardware demands.

When I'm using the 400w psu,I use the radeon 4670 and a single storage drive/ram stick(which i have done for 2 years without issues)
I know the 400w psu won't power the more demanding components fully(which is why i bought the components and a psu),but it should at least boot/start fans.
The 3rd psu I tried that works fine on my brother's pc is a 550w.
All caps are solid/none look blown or leaky/disfigured