[SOLVED] EVGA Z370 Micro - Inconsistent boot, Error leds, C post flashes

[xyster78]

It boots sometimes, only with my old GPU though.

When plugged in but not on, the red (cpu_pwr12v_led) is on (indicates no/low power), as is the (5v sb_led), which might be on normally.
When the power button is pressed the code led shows C for a split second,all fans pulse, and shuts off. If the power button is held it pulses C and fans continue to pulse up to speed until released, and it shuts off. If I keep trying It will eventually boot and run just fine. It usually takes about a minute.
I'm writing this thread on it right now.
It only boots on my older card, an EVGA 1050 sc. I tried to boot on my new EVGA 2070 xc, it doesn't work, ...I tried for a long time.

Specs;
EVGA Z370 micro 121-KS-E375-KR
Intel Core i7-8700K
EVGA GTX 1050 sc (booted ok)
EVGA RTX 2070 xc (won't boot)
G.SKILL Ripjaws V Series 16GB (2 x 8GB) DDR4 3600 F4-3600C16D-16GVK
Samsung 840 Evo SSD 512gb
Corsair CX600 600w

Tests I've tried;

Memory sticks: none, both, flipped, singles in each combination, all the same. Perfectly compatible in bios and seen by hwinfo

Power supply: I wiggled and jiggled all the power connectors, they all look good too. This is from my old build, but it works fine in my other computer, though I haven't needed the 8 pin CPU connector before, maybe that's faulty.

GPU: The 1050 works, the 2070 doesn't. I tested the 2070 in my old build too, its perfect. I connected the power the same way, nothing is loose.
When I install it in the otherwise occasionally working system (in place of the 1050), it never reaches the boot screen.

I've eliminated anything extra; no front io, the motherboard has a power button I've been using. Only one extra fan, I also tried no fans, all the same results.
No other connectors are necessary except my sata for ssd, which i have in sata_0

I think the problem lies in either; the psu, the cpu, or the motherboard.
I'll test on top of the box tomorrow, eliminate any chance of shorting on my case.
Remove the cpu and look close at the socket/pins.

What do you think is happening? Any help or insight will be much appreciated.

 

[xyster78]

Today I first removed all components from the case and reassembled on top of the motherboard box, It boots about the same, power-pulsing with the occasional boot up.
I removed the heatsink and the cpu, all the pins look perfect.
I removed the brackets to the heatsink cleaned off the thermal paste and remounted my heatsink without the bracket just with hand pressure to squish the thermal paste. It boots the same still, although I got it to boot on my rtx 2070 this time.
I tried for about 10 minutes yesterday and it wouldn't boot the 2070 inside the case, but sans cpu bracket and case it boots after about a minute!
Its still doing the power pulse C post thing but I may be getting closer.
I ordered a PSU, I'd rather not rma anything right away.
In a few days I'll get a Corsair HX750i, hope that fixes the rapid C post failure problem.

 

[g-unit1111]

Yeah I wouldn't even attempt to run a Corsair CX with a 2070 or any current GPU. Hopefully the new PSU fixes the problem if not then it's got to be the motherboard.

 

[xyster78]

The new PSU fixed all the problems! It seems the red (cpu_12v_error_led) still comes on when the power is "off" but i'm sure that's normal.

Clearly, I have something to learn about power supplies beyond wattage and efficiency.
Why didn't the other one work? Is it not truly 600watt? Is the power less stable or clean?


The final stats of my happy new build are;

EVGA Z370 micro 121-KS-E375-KR
Intel Core i7-8700K
EVGA RTX 2070 xc
G.SKILL Ripjaws V Series 16GB (2 x 8GB) DDR4 3600 F4-3600C16D-16GVK
Samsung 840 Evo SSD 512gb
Corsair HX750i
Cooler Master Hyper 212 Evo
Thermaltake v21 case

 

[xyster78]

um so, The new psu just popped and died. All is good, it's idling away just fine and I'm power cycling it to make sure its stable every time. I launch into Witcher 3 for a nice 3d load and pop. Lights on mobo indicating power and all, but no response when power button is pressed.
I tested the new power supply on my old board and the new PSU was dead, New parts still do what they do on the old power supply, so no damage I guess.