"I sent it for repair but it came back in the same condition!"That means to me, spiritual_sky, that there is operator headspace.Motherboard was fine when they tested it, and problem is on your end; Or they didn't test it, and shipped it back.Going to go through the basics, so be patient. Mistakes are often made by those of us who are technically qualified, due to simple errors.
http://www.biostar-usa.com/app/en-us/mb/introduction.php?S_ID=390A) The Support Plate the motherboard is mounted to, can be a separate plate, or is an integral part of the metal frame, of the computer case.1) It looks as though there are 10 mounting 'holes'. (Manual gives no details. Looking at it right now. Going by Biostar Support page, and main view)Is there a metal Standoff on the Support Plate, that does Not line up with the mounting holes? If so it is touching an exposed solder joint. This = NoB) Have all the power cables needed connected to the motherboard?1) 24-pin ATX main power cable. (Hooked end of Lock on power cable hooked over Tab on motherboard connector)2) 8-pin EPS +12 Volt power cable.Has 4 Yellow 12 Volt wires, and 4 Black ground wires,
http://www.playtool.com/pages/psuconnectors/connectors.html#eps8Has a Lock on the power cable connector also, and Tab on the motherboard connector. When plugged in properly, and tightly, the hooked end is over the Tab.Connects to Left Upper corner.Not to be confused with an 8-pin PCI Express power cable,
http://www.playtool.com/pages/psuconnectors/connectors.html#pciexpress8[NOT an inference towards you, but I have seen people who could destroy a steel ball bearing in a sandbox, with a rubber mallet. They would try to cram an 8-pin PCI Express power cable, into a connector on the motherboard for an 8-pin EPS +12 Volt power cable ]Three Yellow 12 Volt wires, FIVE Black ground wires.A 6-pin PCI Express power cable will fit, and work, in a connector for an 8-pin EPS +12 Volt power cable. Problem is it does -> Not, deliver the power that an 8-pin EPS +12 Volt power cable will deliver. A graphics card senses whether a 6-pin, or an 8-pin power cable is being used.SOME graphics cards will not work unless it is an 8-pin.
http://www.playtool.com/pages/psuconnectors/connectors.html#pciexpress[See the power adapter cable on the right? Notice it uses TWO 4-pin standard Peripheral power cables. Some people make the mistake of only using one. This = NO ]3) 4-pin standard Peripheral power cable. (Misnomered as a 'Molex' power cable)Provides auxiliary power for the graphics card.Manual states, "This connector is an auxiliary power connection for graphics cards.EXCLUSIVE power for the graphics card provides better graphics performance."
http://www.playtool.com/pages/psuconnectors/connectors.html#peripheralMay be reaching here, but if the graphics card you are using does ->Not require an additional power cable connected directly to it, but does ->max out what the motherboard can provide, not connecting that additional 4-pin power cable may be the problem.May need it even if the graphics card does have it's own power cable/s.Graphics card requires a power cable? Better have it plugged in.Requires TWO power cables? Better have two power cables plugged in, and Not just one.Graphics has a problem? The motherboard will not start, or P.O.S.T.Using a single Graphics card.HAS to go in the PCI Express x16 slot next to the Northbridge chip, under the processor socket. (PEX16_1)The PCI Express slot that is the same length at the bottom, is a PCI Express x4 slot. This = No.[Top slot next to Northbridge, {Copper finned Heatsink is on top of Northbridge chip},PCI-Express x16 slot. Slot 1.Next slot down is a PCI-Express x1 slot.Next slot down is a PCI-Express x16 slot. It is Slot 2.Next slot down is a PCI-Express x4 slot ]C) Simple error; Front Panel header pinout.Front Panel header (JPANEL1) is at the bottom right corner.Pins 1 through 8 are on the Bottom row;1, 2, 3, 4, 5, 6, 7, and 8.Pins 9 through 16 are on the Top row;9, 10, 11, 12, 13, 14, 15, and 16.A) Pins 1, 2, 3, and 4 are for an Internal speaker. For BIOS Beep Codes. Pin 1 is for the Positive (+) wire. Pin 4 is for the Negative (-) wire.B) Pins 5 and 6 are for the HarDDrive activity LED.Pin 5 is for the Positive (+) wire.C) Pins 7 and 8 are for a Reset switch, IF a Reset switch is used.D) Pins 9 and 10 are N/C. Not connected. There is No Pin 11.E) Pins 12, 13, and 14 are for a dual color Power On LED.Pins 12 and 13 are for the Positive (+) wires, Pin 14 for the Negative.If just using a single color Power ON LED, use Pins 12 and 14.F) Pins 15 and 16 are for the Power On switch.Make sure the Power On switch is good. Remove the wires, touch a Jewelers flat tipped screwdriver to the two pins - Briefly.Comes on you have a bad Power On switch.Do you KNOW that the Power Supply is good? Tested the three main voltages?(3.3 Volt power rail5 Volt power rail12 Volt power rail )Need to know how post in a Comment.Just to ask; What is the maximum rated Wattage of the Power Supply, what is the Amperage of the 12 Volt power rail/s, and what is the manufacturer, and model number of the graphics card?Regards,joecoolvette