Mobo will not turn on

[urgalweiser]

whenever I turn on the switch for my PSU, it automatically starts up. The motherboard does not turn on. This is the 2nd PSU I have tested.Running a Thermalmaster TM420 PSU, a Gigabyte GA-EP43T mobo and 2gb r=ddr3 ram with an Amaze 9800GT GPU

 

[popatim]

Sounds right to me. Many PSU's do this odd behavior when you first turn them on from the switch on the rear. The motherbd will not actually power up until you press the power switch on the front of the case is pressed (or the motherbd 'pwr sw' header is momentarily shorted) and it receives a 'power is ok' indication on the 'pwr_ok' line at the motherbd's 24pin connector.

 

[urgalweiser]

No, the problem is that when i press the button, the fans spin for half a second and stop and the mobo does not star
.t

 

[popatim]

Did this used to work or is this a new build with older parts?

 

[urgalweiser]

Did this used to work or is this a new build with older parts?

Yes it did. It just suddenly stopped working

 

[R0GG]

I have an Asus Formula V mobo on a seasonic 850 Gold PSU, at times I get this behavior when pushing start button would make PC turn on for few seconds then shuts down right afterwards, to get around this I turn power off PSU all together, then re-power it after 30 seconds " et voila ! " ( for and that's how it's done in french ), usually after an event of this sort when at the bios post I see AMD CPU cores activation failed or something of that sort, I quickly press ALT+CTRL+ DELETE to reboot and next post has no message error and continue to windows.

Some other times it's more tenatious even after cutting power off the mobo totally the issues persists, solved by resetting bios ( switch on the mobo selecting default profile )

SO I am thinking you might be experiencing the same issue: an instable Bios inherently (buggy) or because of instability due to some settings or after longer gaming sessions or overheating etc.

When this thing happen try to disconnect mobo from power completely by switching your PSU off from it's rear button for 20-30 seconds, or better unplug the power cord from rear of the PSU for about 30 seconds, turn it back on and push start button of your computer and pay attention to the Bios post error messages.

 

[urgalweiser]

I have an Asus Formula V mobo on a seasonic 850 Gold PSU, at times I get this behavior when pushing start button would make PC turn on for few seconds then shuts down right afterwards, to get around this I turn power off PSU all together, then re-power it after 30 seconds " et voila ! " ( for and that's how it's done in french ), usually after an event of this sort when at the bios post I see AMD CPU cores activation failed or something of that sort, I quickly press ALT+CTRL+ DELETE to reboot and next post has no message error and continue to windows.

Some other times it's more tenatious even after cutting power off the mobo totally the issues persists, solved by resetting bios ( switch on the mobo selecting default profile )

SO I am thinking you might be experiencing the same issue: an instable Bios inherently (buggy) or because of instability due to some settings or after longer gaming sessions or overheating etc.

When this thing happen try to disconnect mobo from power completely by switching your PSU off from it's rear button for 20-30 seconds, or better unplug the power cord from rear of the PSU for about 30 seconds, turn it back on and push start button of your computer and pay attention to the Bios post error messages.

I tried this, and now the GPU and MOLEX fans are spinning, the CPU cooler fan is twitching back and forth. and it is not booting

 

[R0GG]

ok!
STEP I : General Troubleshooting.
- I would temporarily strip mobo off any unnecessary components and leave it with bare minimum peripherals keyboard, mouse, graphic card (remove it if your mobo has an integrated video that you could use), single monitor,(disconnect all other CABLES or peripherals CD drives and all hard drive including system drive) (ideally remove mobo from the case )

- I would double check every single connector for tightness PSU cables included ( PSU end for modular one) fans PCI-e mobo and CPU power
- Make sure CPU cooler Fan is connected to mobo dedicated CPU fan header and is functional (some mobos would refrain from booting otherwise if Fan not detected or defective).
- I would make sure RAM modules are compatible, Non defective and VGA are well seated ( would re-seat them for more assurance) (RAM slot seating order as per mobo manufacturer specs)
- I would make sure there are no potential metal or shorting objects or astray screws underneath laying around in the case.
- I would check PSU fan for spin ( depends on PSU), VGA and CPU fans as well and keep an eye on their behavior during the boot process.

STEP II: THE BIOS.
- Clear CMOS (jumper on your mobo :How to at page 30 of your mobo manual ---> http://download1.gigabyte.us/Files/Manual/mb_manual_ga-ep43t-usb3_e.pdf
- Your mobo has 3 BIOS features: (PAGE 66 of mobo manual )
1. Xpress Bios rescue >> automatically loads a back up bios that it hides on system drive when main Bios gets corrupted.
2. It has dual PHYSICAL bios: a main Bios and back up Bios which is configurable thrugh Bios interface and is loaded automatically if main one is damaged ( independent from hard drive availability) l>>> https://www.gigabyte.com/microsite/121/tech_dualbios_setup.pdf
3. It supports Q-FLASH : allowing to Flash main Bios, update it from a flash Drive without going through the Bios interface through a keyboard shortcut , see here >>> https://www.gigabyte.com/microsite/121/flashbios_qflash.pdf
During Bios Post your mobo Biios displays all these options and the keyboard keys to press .

Basically boot your system with bare minimum hardware, and do a Bios reset if needed.