Asrock Z77 Extreme4 works with 2 DIMMs, error 55 with 4

[SpawnRulz]

I recently decided to upgrade from 8 to 16 GB of ram in my system. So I purchased another 2x 4GB kit of Vengeance Pro 1866 RAM (CMY8GX3M2A1866C9R).

I've had my current setup for over 4 years without issue. I was hoping I would just pop the new ram in and I'd be up in running, but instead I'm getting error code 55 (RAM not installed I believe) with all 4 DIMMs in the system. If I take the 2 additional DIMMs out the system runs just fine.

The manual says RAM should be in slots A1 and B1, A2 and B2, or all four slots for dual channel to work. I've since tried with ram in A1 and B1 and A2 and B2, and both work fine. I'm also aware that despite the RAM being the same brand, type etc, that since they are not from a 4x4GB kit that could be an issue. I've tried mixing the sticks from both kits without issue as long as I only have a total of 2 in the system. Once I put a 3rd DIMM (or 4th) I go right back to getting error 55. The system will turn on for a few seconds, get error 55, then reset itself, and stays in that loop until I turn the power off, it will not POST. I've tried clearing the CMOS as well, which didn't help.

CPU is i7-3770k.

Any help/suggestions would be greatly appreciated. Thanks.

 

[Paul NZ]

Someone had a similar prob on another forum. One of the pins on the CPU were bent. Which caused the same error

 

[SpawnRulz]

So it's possible that everything in my system would be working fine for several years with a bent pin? I would have thought I'd run into other issues by now, but I'll check it out. Thanks.

 

[Paul NZ]

Did you try putting the sticks you had into the slots that brought up the error? I guess so since there was nothing in the slots till you brought extra ram

 

[SpawnRulz]

Yes. Before I bought the additional RAM I was using slots A1 and B1. Currently I have the new ram I bought in slots A2 and B2, and everything is working normally. I've also tried mixing 1 old stick with 1 new stick and that worked fine as well.

 

[SpawnRulz]

Went ahead and checked for bent pins this morning, didn't see any, and I'm still having the same problem. System runs great with RAM in slots A1 & B1 or A2 & B2 (the correct config for dual channel) but as soon as I add a 3rd of 4th stick, I get error code 55.

 

[Paul NZ]

Got an eraser?? Try removing the ram that wont work, and rub the contacts. See if that helps. Maybe the slots are faulty?

 

[Calvin7]

You might call it upgrading from 8 to 16 GB of ram by doubling the kits. Some people call it saving money by using two kits. Fact is, Corsair does not guarantee such combinations to work. They suggest to try running at a slower memory clock speed.

G.Skill FAQs:
http://www.gskill.com/en/faq/DRAM_Memory

Q: I want to install more memory, in addition to my existing memory kit. What are my options?

A:
We do not recommend mixing memory kits, regardless of brand or model.

By mixing memory kits together, there may be compatibility issues such as unable to boot or unable to operate at rated specifications.

Each of our memory kit are thoroughly tested to ensure compatibility within each memory kit. And because we have not tested our memory kit with your existing memory kit, we cannot guarantee compatibility when multiple kits are used.

 

[SpawnRulz]

Thanks for the responses. The weird thing is the modules from both kits do work together when I only have 2 sticks total in the system. Perhaps there is something different when going to 4. For now I'm just going to return the additional RAM and live with 8 gigs. I guess the other option would be to replace the two 4GB sticks i have with two 8 gig sticks.