No post / No power to Bios

[pantz]

 Hello everyone ,  i am having a frustrating time getting my GA-MA790GPT-UD3H rev 1 to POST... it seams the MB is not getting any or enough power to POST, i my machine was  shipped over from the US to the UK, it was working fine, upon receive my machines in the UK i opened it up and it seems that someone in the US was inside the machine, i found a loose MB and CPU had been taken out an put in backwards.

I have since had the MB checked out since i was still in warranty ( gigabyte said the MB is fine) and have purchased a new CPU AMD 2 Quad 965 BE, so i was left with just the PSU to check ( Corsair TX750W) i have been to their forum and they said to do the paper clip test to see if the fans spins up, and it does.but when i plug the ATX power cable in there is no power to the board, but i do get the case and CPU fan to spin up.

Someone also said in the forum that " the manual for the mother board shows a -5V pin on the ATX 24 pin mother board power connector. A TX750 does not have a -5V rail."

This PSU worked fine in the US, now it does not want to work, and the cost of RMAing the PSU  40 Pounds)  is not far from the  cost of a new decent PSU. i do have a 500W power supply in another machine, i was thinking of trying that, but if the MB still does not post,  then the PSU that i have is still probably good, Any ideas would be welcomed ,

Thanks

[Dark Mantis]

Hi

My first thought would be do you need to change the voltage on the PSU or is it autosensing ? If it isn't automatic in changing vboltages you could well have blown it or at least blown the fuse if you are lucky!

Failing that make sure that the 24 pin power lead and the 8 pin ATX lead near the CPU are both firmly seated.

[pantz]

Hello thanks for the reply, the TX750W PSU is Auto sensing ..... but i did not directly plug it into the socket,  i used a Adapter that changes the voltage from 240 to 115, its the same adapter that i use to power up my laptop, and the laptop powers up just fine,

[Dark Mantis]

In that case just plug it into the mains supply directly. Your adapter might be the reason for your problems. The desktop system will draw a lot more power than your laptop.

[pantz]

Hello once again, well i think my Corsair TX750W PSU is DEAD, i plugged it right into the wall, and connected the 24 pin connector to the board an nothing, so i think i am going to RMA the PSU,, but i did find an old power supply that i know works,

http://support.dell.com/support/edocs/systems/dim4400/techov.htm

but its only has a 20 pin connector, that should be enough to allow the MB to POST and go into the BIOS at least, ? Right ? once again thanks for the help.

[Dark Mantis]

It probably won't work without the full power cables connected, don't forget the ATX 12v cable as well.

[pantz]

Thanks, but i just found out that the dell power supply had the ATX connector is proprietary to dell PC, look like  i am going to have to talk the one out of the working machine to got the other machine to atleast  POST/BIOS.

Thanks

[pantz]

Hello Everyone , I finally got my Machine to work  it was the power supply the was bad, i have had the machine up and running for a few weeks now, it is running pretty well so far, i am  doing 2 years of Windows updates and software updates for my X64 machine,  i updates the BIOS to F6, but there is a F7C BIOS update available. should i update the BIOS to a F7C or Leave it at the F6, i don't want to update the BIOS if it is not necessary.

Thanks in Advance.

[absic]

Hi there,

pleased you have managed to get things back up and running but it was a shame that your PSU had to be replaced as they don't come cheap. 

With BIOS I usually recommend that you update to the latest version only if you are having a problem. If everything is fine you don't really need to do so and the old adage of: "If it ain't broke, don't fix it" is well worth remembering.

Having read through the whole thread you state that your Mobo is rev 2.0 and that the latest BIOS is F7c is this correct? The reason I ask is, that trying to find your board is proving a little tricky for me and I can only find a rev 1.0 version on the Gigabyte site. 

[pantz]

Hello Again,  my mistake on the REV # on the MB, it is a Rev 1, i am seeing some kind of issue, my CPU seems to be running at  2700Mhz for most of the day, i just reset the motherboard to optimal defaults, and when i booted back up  it ran for 3400Mhz for a minute and went back to 2700Mhz, it has been doing that for a few days now, i thought it was to run at 3400Mhz,out of the box ? ,  unless i changed something, which i have not ?

[autotech]

Did you turn off all the power saving features like cool n quiet? There are i think 3 different ones you have to turn off in your bios. The throttling back is a power saver feature.

[Dark Mantis]

Hello Again,  my mistake on the REV # on the MB, it is a Rev 1, i am seeing some kind of issue, my CPU seems to be running at  2700Mhz for most of the day, i just reset the motherboard to optimal defaults, and when i booted back up  it ran for 3400Mhz for a minute and went back to 2700Mhz, it has been doing that for a few days now, i thought it was to run at 3400Mhz,out of the box ? ,  unless i changed something, which i have not ?

It is just the way they work. They will throttle back from full power/speed unless they need it. If you start a program that need full power you will notice that the CPU speed ramps up to accomodate it.

[pantz]

 Hello again Everyone, i went into the BIOS and manually changed to Multiplier to X17 and the CPU is now running at 3415Mhz with an idle temp of 38-40C. Cool an Quiet is Disabled, and the CPU fan is running at full speed, i dont think it will trottle down now. i will let it run for a couple of days just to make sure. then I will further reduce the amount of "AUTO" setting after a day or two.

Thanks for all the help.

[Dark Mantis]

No problem just please update the thread for anyone who is interested later. 

[pantz]

Hello Again, i went into my BIOS and checked my RAM and CPU settings and i change my CPU voltage from 1.375v to 1.350, and i saved it, for some reason it did not take, also i have 2 different CPU voltage readings from CPUZ and Core temp, which one is the correct reading?

Thanks in advance