Refusal to POSt 50% of startups

[silverz]

Just put in a new motherboard, Asus TUF z270 mk2 and a new cpu, i5 7600k with the appropriate memory and 50% of startups the system just black screens when you power it on.

The fans spin but with a different sound than what they do under normal operation (much quieter) and the lights on the board come on but the screen it just black.

Currently my only fix is to power off and back on again and repeat until it boots normally, after which everything functions perfectly.

Any idea of possible causes?
PSU is ocz 700w so I doubt it's lack of power or cheap psu. Previously ran i5 2500k at 4.6ghz and never encountered this once until upgrade.

 

[shrapnel_indie]

Just put in a new motherboard, Asus TUF z270 mk2 and a new cpu, i5 7600k with the appropriate memory and 50% of startups the system just black screens when you power it on.

The fans spin but with a different sound than what they do under normal operation (much quieter) and the lights on the board come on but the screen it just black.

Currently my only fix is to power off and back on again and repeat until it boots normally, after which everything functions perfectly.

Any idea of possible causes?
PSU is ocz 700w so I doubt it's lack of power or cheap psu. Previously ran i5 2500k at 4.6ghz and never encountered this once until upgrade.

Just for the record, what is your full current build now?

One thing I'd do is double check the mounting of your motherboard, just in case there is some shorting going on between the standoffs and the motherboard (or the screws and motherboard,)

 

[octavecode]

any debug leds on the board? if not connect a speaker on it and count beeps

 

[shrapnel_indie]

any debug leds on the board? if not connect a speaker on it and count beeps

Need BIOS brand too (prob in manual) to ensure proper translation.

 

[silverz]

Just put in a new motherboard, Asus TUF z270 mk2 and a new cpu, i5 7600k with the appropriate memory and 50% of startups the system just black screens when you power it on.

The fans spin but with a different sound than what they do under normal operation (much quieter) and the lights on the board come on but the screen it just black.

Currently my only fix is to power off and back on again and repeat until it boots normally, after which everything functions perfectly.

Any idea of possible causes?
PSU is ocz 700w so I doubt it's lack of power or cheap psu. Previously ran i5 2500k at 4.6ghz and never encountered this once until upgrade.

Just for the record, what is your full current build now?

One thing I'd do is double check the mounting of your motherboard, just in case there is some shorting going on between the standoffs and the motherboard (or the screws and motherboard,)

Current build is the i5 7600k (currently overclocked but problem was there before overclock was applied), the Asus Intel TUF Z270 MARK 2 LGA 1151 ATX Motherboard, Corsair vengeance 16gb kit (2x8gb) @ 3000, 2x GTX 970 gpu's, the psu is the OCZ 700MXSP, some old 1tb hard drive and a 256gb ssd (kingston SV300S37A240G)


I doubt it's the mountings as I only use 4 of them (old case, lost the other standoffs) but I'll have to check the board seating when I get time.

 

[silverz]

any debug leds on the board? if not connect a speaker on it and count beeps

I believer there is a debug LED, I had forgotten about this.
I'll try a few restarts and see what light it is giving.

 

[silverz]

any debug leds on the board? if not connect a speaker on it and count beeps

Ok... quick update.
Rebooted system and as expected no post for the first 2 attempts.

LED lights are not illuminating at all when this happens, the manual suggests they should always show a colour (green ok, orange boot device, dram yellow, cpu red etc).

I have noticed a quick shutdown and restart can cause the no post to occur more often/repeatedly but if i power off at the psu switch and wait a few seconds for a full power down it seems a lot more likely to boot normally after this. not sure the significance of that.

 

[ko888]

Try using a better quality Intel Haswell or later compatible power supply unit.

 

[octavecode]

Reset the bios, disconnect all drives (power too), use one ram dim and do some reboots into bios settings...
if this keeps happening you might wanna RMA the board.