I just finished building a new PC using i7-4770K, Asus Z87-Plus mb, 8GB (2x4) G.SKILL Rip Jaw, onboard GPU and OCZ 530 PSU.
At first power-on test, the CPU fan and all case fans came on as expected, but the mb's CPU LED stayed on, indicating a CPU problem.
I removed a stick of memory and tried again. Same result.
I then disconnected all mb connectors except the 24-pin and 8-pin power connectors ( a nice fear feature of this mb is it has its own power-on switch). Same result.
I then pulled the mb out of the case, to ensure no shorts with standoffish or I/O shield. Same result.
I next removed the remaining memory stick (no memory installed at this point), just to see if the symptom would change. It did. This time the CPU LED flashed on briefly, then the DRAM LED came on and stayed on, as expected (no memory). Here's where things got interesting.
Powering off and then back on sometimes caused the CPU LED to stay on, but other times caused the DRAM LED to stay on. In other words, POST was sometimes failing in the CPU section, but other times getting past that section and into the DRAM section. More often than not the CPU LED would stay on, with the DRAM LED staying on in maybe 1 in 10 tries.
However, if I installed even one memory stick, I could never get past the CPU LED staying on.
I swapped out the PSU with one from another (working) PC, just to make sure this wasn't a PSU cable problem. No change in the symptoms.
I checked the CPU socket for bent pins - everything looked clean - and even went so far as replacing my Zalman CPU cooler with the stock Intel fan. No change.
I obviously have either a bad mb or a bad CPU. I suspect the mb because I (stupidly) bought it as an 'open box' item that had supposedly been retested after it was returned.
Is there anything else I can do at this point to further isolate the problem and identify which component might be failing?
At first power-on test, the CPU fan and all case fans came on as expected, but the mb's CPU LED stayed on, indicating a CPU problem.
I removed a stick of memory and tried again. Same result.
I then disconnected all mb connectors except the 24-pin and 8-pin power connectors ( a nice fear feature of this mb is it has its own power-on switch). Same result.
I then pulled the mb out of the case, to ensure no shorts with standoffish or I/O shield. Same result.
I next removed the remaining memory stick (no memory installed at this point), just to see if the symptom would change. It did. This time the CPU LED flashed on briefly, then the DRAM LED came on and stayed on, as expected (no memory). Here's where things got interesting.
Powering off and then back on sometimes caused the CPU LED to stay on, but other times caused the DRAM LED to stay on. In other words, POST was sometimes failing in the CPU section, but other times getting past that section and into the DRAM section. More often than not the CPU LED would stay on, with the DRAM LED staying on in maybe 1 in 10 tries.
However, if I installed even one memory stick, I could never get past the CPU LED staying on.
I swapped out the PSU with one from another (working) PC, just to make sure this wasn't a PSU cable problem. No change in the symptoms.
I checked the CPU socket for bent pins - everything looked clean - and even went so far as replacing my Zalman CPU cooler with the stock Intel fan. No change.
I obviously have either a bad mb or a bad CPU. I suspect the mb because I (stupidly) bought it as an 'open box' item that had supposedly been retested after it was returned.
Is there anything else I can do at this point to further isolate the problem and identify which component might be failing?
Facebook
Twitter
Instagram