CPU or Mobo problem?

[Uncle Petey]

Hi guys, here's today's conundrum

As the title says, I'm not sure where the fault lies, so here's the situation:

I just installed a used 2600K on an Asus P8Z77-V as an upgrade from a 2500K.
I had 4x4Gb of Avexir core series RAM installed with no problems on the i5.

When I put the 2600K in, the mobo DRAM LED stayed on constant and it wouldn't boot to bios. I held the memtest button down so it could do it's own checks, but after doing that, the problem remained so I thought that maybe one of my sticks had kicked the bucket.

I then tried one stick at a time in slot 1 and the PC boots no problem with any one stick installed, so that tells me the RAM is fine.

It seems the problem lies in using slots 1+3 for dual channel as any two sticks in slots 1&2 results in a normal boot.

Could a slot have died just like that, or do you think the new CPU may have a memory controller issue, or something else entirely?
Anything else to check or further tests I could run to narrow it down?

I suppose I could try the 2500K again with dual channel, but it's a bit of a pain tbh and was wondering if any of you had resolved a similar issue?

Thanks for any advice

 

[Uncle Petey]

Ok, I've tried the 2500K again and it boots fine with RAM in slots 1 & 3.

ED: It's actually slots 2&4, but whatever

Is the CPU memory controller to blame here or what? I tried the 2600K with BF4 using 4Gb ram and it certainly works. Temps were low at stock 3.8ghz boost with a passive K2 fwiw, so I'm baffled...

 

[Uncle Petey]

Well... Problem kind of solved (for now).

I just tried the 2600K again, but with the stock cooler instead of the K2 mainly because taking that thing on and off was getting tedious

Anyway, it booted fine with a couple of sticks in dual channel, so the controller doesn't seem to be the issue thank goodness.

Pressure from the K2 may have been the culprit, but I've always been very careful not to over-tighten it and there's never been a problem with the 2500K, so maybe this new chip is just a delicate flower or something...
Still not sure why it would work with one or two sticks in single channel and not two in dual though.

Anyway, the loop will be back on soon, so no worries about massive coolers buggering things up hopefully

ED: K2 back in with all four sticks and things are fine... I dunno, computers eh?

 

[wazza300]

yeah an overtightened cooler or some cases the motherboard flexing can cause memory/banks issues

 

[Uncle Petey]

Yeah, could've been tightened down a fraction too hard or something. I dunno...

Bios is always up to date, my friend

 

[setter]

Done this a few times with the k2 on my z77 setup. Instant panic attack when it first happened. The tiniest slackening of the screws sorted it.

 

[Uncle Petey]

Hmm, perhaps I wasn't as gentle as I thought...