Hello. I have three boards (P8P67, P8P67 EVO, P8Z68 - V/GEN3) and they all have same problem. If you put TWO memory sticks in the same channel mother board show postcode 55. In any other combination is working fine. So to be clear i made a pictures which combinations dont work:



All ram stick are ok, processor is ok i checked them on couple different boards and all is working fine. All boards have new bios from official website. All crucial memory voltages are fine. All conections between cpu and memory are fine i (checked it with tester). Is it a HUB or SIO malfunction or something else? Thank you for any advise.

Which processor?
The processor is responsible for the RAM, it contains the memory controller.
Are you all the same memory sticks? what frequency? take a photo of the stickers on the memory sticks.

Processor and all memory sticks are 100% good i tested them on other asus boards. I use celeron 1610 for testing but put now i5 2500k and only different is that now there is no code 55 motherboard starting up but dont see ram in the bios and show memory speed (0 mhz). I tried different ram stick (corsair, hynix, hyperx (1GB, 4GB, 8GB sticks)) all the same result. It is not ram or processor issue. It is 100% motherboard problem.

Try to measure all voltages on memory - VDD, termination, SPD. Also you should check 5DUAL моsfets

first you need to flash the BIOS with the programmer.
you did not indicate what frequency your memory sticks have, if they will not work correctly together with different frequencies!

1. All memory voltages are in good range in all slots.
2. New bios was installed with a programmer.
3. Bios shows ram speed at 1066 mhz but only in ram menu at the front page it shows 0 mhz. By default they should be 1333.
4. When i test i insert all ram stick with a same speed, type and vendor.
5. Ram and processor are 100% okej i checked it today at P867 rev 3.1 and p8z68 - v lx and all working fine.

I quess it is some HUB malfunction. I think i will change a HUB in this weekend to find out. Any other ideas guys?

I have changed HUBS in all three motherboards and they are working correctly now, but had meanwhile ASROCK H67DE3 with same symptoms and bios reflash helped. So conclusion is to check bios first and if that not help and all voltages are correct it means you need to change hub. Thanks for help guys.