Computer with recently RMA'ed parts won't POST. It worked 2 days prior with same settings.

CascadiaHiker

Commendable
Jan 1, 2017
6
0
1,510
Hey guys I’m having a significant problem with a computer I built. Sorry for the long post, I’ve tried numerous troubleshooting steps but it’s just been one thing after another including sending parts in for warranty return. I’m nearing the end of my rope and need assistance, thank you.

Tl;dr computer won’t POST, worked two days prior with same setup. Recently RMA’ed PSU and motherboard. Skip to the last two paragraphs for the most recent update.

Build – https://pcpartpicker.com/list/CgffGf running W10

I built a computer in November 2016 and it worked well until the end of December 2016. On New Year’s Day, I found it powered on with a black screen that was unresponsive to input so I turned it off by holding the power button. I waited a minute to try turning it back on but it wouldn’t respond. I tried a few more times and found that about 9 times out of 10 the power button didn’t do anything. The other 1 time, the computer would receive power for a split second and then turn back off. The symptoms sounded like a power supply problem so I warranty returned it.

The RMA was being delayed so I requested a similar model to expedite the process to which Corsair agreed. The original PSU was a Corsair CXM650, the new one is a Corsair RMx650. While waiting, I tested my computer with a different and known working power supply; an EVGA 430w model. It produced the same symptoms so I requested a warranty return with the motherboard manufacturer ASUS.

When the new power supply and what I assume was either a repaired or replaced motherboard came in (ASUS was vague what they did with it), I “breadboarded” the components one at a time and used the motherboard LEDs to judge if the computer could detect the components. I don’t have a speaker to listen for POST error codes. Each worked and I could boot into Windows. While using the computer, I could use programs including a hardware monitor (Speccy) that said only 1 of 2 RAM modules were detected. I was not able to test the graphics card. Temperatures were normal and the computer seemed to be operating normally.

A couple of days later I attempted to turn the computer on. When the power button was pressed the machine sounded like it was on with all fans spinning but there was no display. I turned it off and opened the case and tried again. The MemOK! LED was lit and not blinking, possibly a RAM problem? I tried every combination of RAM: no RAM and then each stick tried in each slot. I tried plugging the HDMI into the motherboard, tried removing the graphics card, resetting the CMOS battery (which produces its own separate symptom: on a cold boot the machine will power up for a second, power down, then power back up and become stable). I tried pressing the MemOK! Button next to its LED, it resets the machine and produces the same symptoms but the MemOK! LED is lit and blinking. The blinking starts slowly but gradually changes to a faster blink. When the memory LED changes speeds, the CPU LED flashes, unsure if related but relevant.

Just a thought, the warranty returns for the power supply and motherboard were both accepted, does that mean that there are other components that could be bad as well? Could it have been that the PSU went bad and fried other components?
 
for reference>>>>>https://www.asus.com/support/FAQ/1012266

If its on solid it indicates a ram failure..... but because the ram controller is in the cpu could be a cpu failure also.....

blinking means it is checking ram does not indicate that ram has failed but it being on solid means there is a ram issue or cpu(because the ram controller is in it)


also check that your cooler is not on to tight it could be motherboard warping causing your issue (why it worked outside of case)
 

CascadiaHiker

Commendable
Jan 1, 2017
6
0
1,510


Thank you for the feedback. Yes its on solid, the bizarre thing is the previous time I used the computer after assembling it inside of the case is that it didn't have that problem. Additionally the CPU seemed to work fine the day prior too. Just in case the CPU fan was too tightly installed I loosened it slightly and tested but to no avail.

Between when it worked while inside the case and today, not working but still inside the case, I wonder what happened? No settings, hardware, or conditions have changed.

At this point should I be reaching out to the CPU, RAM, and GPU manufacturers for RMAs? Should I include the hard drives too?