ASUS H81M-V3 does not boot

[madan1072]

I have assembled a PC using ASUS H81M-V3 motherboard, Corsair 2X8GB Ram 1600 Mhz, Pentium 2 COREmira G3246 CPU and am using a 300 watts power supply taken from old Inspiron 530. I am using built-in Intel graphics for the time being, I have SATA 2 two nos HDD with Vista Ultimate on one and Ubuntu 14.04 on another, and a CDRW Drive. These parts were also taken from my old Inspiron 530, and were in good working condition. Problem Statement: The power up light vanishes are a few seconds, no display on VGA/HDMI monitor comes up. I have tried both ASUS Mobo CD, as also, Win Vista Ultimate CD. Observations: The CPU and Case Fans run normally. I have tried using an external HP DVD as well ut system refuses to boot... All PSU calculator show 300 watts, requirements at various websites. However, ASUS H81M manual supplied at one place say minimum 350 Watts PSU??? I have tried disconnecting the HDDs / CD-Drvei as well. No Joy. One Blogs says that because of delays in start up, or due to use of DA convertors by ASUS, a specific power supply which does not use fast boot should be used. I am willing to replace the PSU, Please advise which possible ones/make if PSU is the culprit. The coonections are I suppose are okey after multiple checks against the manual...Please help and offer Advise

 

[i7Baby]

Go through Tom's checklist - http://www.tomshardware.com/forum/261145-31-perform-steps-posting-post-boot-video-problems

Does it post - load bios - without the OS drive(s) connected?

 

[madan1072]

Go through Tom's checklist - http://www.tomshardware.com/forum/261145-31-perform-steps-posting-post-boot-video-problems

Does it post - load bios - without the OS drive(s) connected?

Hi, thank you for your suggestions but all these steps were followed, and the problem reported still occured.
2. It does not POST or show the BIOS screen (I have tried both with and without HDDs connected and with or without ASUS CD-Rom / Win 7 CD in the DVD drive).
i) Only the Cabinet And CPU Fans run normally
ii) There is no heating anywhere
iii) What is perhaps a likely clue is that the blue LED of the main on/off switch comes up but goes off after 10~15 secs. My brother who has done a lot of PC/Laptop assemblies as a hobby, observed that it could very much be the PSU, which is rated for 300Watts, and I should get a 450 watts PSU... I have since bought a Cooler master thunder 450 watts that was just delivered, I will try it out to-morrow... But I am not sure it is the solution...

 

[i7Baby]

Disconnect the OS drive, attach an internal PC speaker and see what post/beep code you get per http://www.computerhope.com/beep.htm

See your mobo manual for where to put the speaker and what sort of bios you have - ami or ibm

 

[madan1072]

Go through Tom's checklist - http://www.tomshardware.com/forum/261145-31-perform-steps-posting-post-boot-video-problems

Does it post - load bios - without the OS drive(s) connected?

Hi,
No Beeps though Fans run.The blue LED comes on pressing the start button, but it goes off within a few seconds. Normally in Inspiron the color of the start switch changes to blue when it is running, in my case it only remains yellow. Iconnected a small speaker, but could not hear any beeps... Is there a way to find out whether the CPU and Mobo are okey or I have junk both...

 

[i7Baby]

Are BOTH power supply connectors plugged into the motherboard?

 

[madan1072]

Are BOTH power supply connectors plugged into the motherboard?

------------
Yes please. There is a 24 pin at the mobo front edge and a 12v connector near the psu (left edge if viewing from behind) marked ATX 12 V...
Thanks

 

[i7Baby]

"am using a 300 watts power supply taken from old Inspiron 530." - is sus. What 12v. 5v and 3.3v voltage readings are you getting from bios?

Disconnect one of your OS HDDs and see if it boots.