Code 55 with DDR5 kit.

[matrosov1]

Good Afternoon Have a weird issue with my DDR5 z790  build.  Z790 Maximus Hero MB gen 13 i9 intel processor Gskil 2x48 6800 memory kit. 
G.SKILL Ripjaws S5 Series 96GB (2 x 48GB) 288-Pin PC RAM DDR5 6800 .  Plug in both sticks in slot 2 and 4 counting from CPU as per instructions I get code 55.  Plug any of the sticks as a single into any slot other than 4 same code.  Plug in any of the sticks into slot 4, farthest from CPU  everything works fine.  Checked fifty times for proper seating of the sticks they are fine.  Checked CPU for bent pins they are fine too.  System runs fine and a stable on any single stick from the kit but refuses to boot up when both plugged in.  Any suggestions on what I should do next RMA MB,CPU, memory all three and start from scratch?

Thank you for your help.  

[FireRx]

I would sucspect voltage is the issue on those kits. that some huge memory . what the current voltage your usings. Are you using any XMP seettings?

[matrosov1]

Hi and Thank you.  I haven't touched any settings in BIOS, everything is default so I'm suspecting itt's running at default 1.3

[matrosov1]

As an additional question why would a single stick be recognized only on slot 4 and not on any other slot?  I am  not all too familiar with DDR5 but if I recall DDR4 you could plop a single stick on any slot on MB.  

[Hopper64]

I'm at work and can not check the QVL. Is that kit on the list?

Do you have another memory kit that you can test?

[matrosov1]

It is, they misspelled the part number identical RGB kit is on their QVL and Gskill lists the one I have as compatible.  I just ordered another 2x32 kit will try to plop it in when it arrives still perplexed as to how another kit will work if  sticks in the original  work individually unless it's balking at 2x48 capacity and wants to see 2x32 but MB  and CPU are specced for up to 128 so it should take 96 in theory. 

[FireRx]

hmmm, interesting.  that is curious. you on the original CPU retention system?  The intel one or an aftermarket Contact Plate.  and were you seeing all of the memory with bios 0904? I would test with that other memory kit you have coming first thought before taking anything else apart.

[matrosov1]

All stock ASUS z790 hero board.  Arctic AIO backplate made sure five times I didn't tweak it sideways when installing it. Not sure what BIOS that board came with but it wasn't recognizing memory as well I updated it to whatever latest they have on a website still nada. 

[Rethum]

If you look at the Z790 Maximus Hero manual, page 1-6 it states: "You may install 8GB, 16GB, 32GB unbuffered and non-ECC DDR5 DIMMs into the DIMM sockets."  Assuming that a 48GB stick won't inherently be an issue the combability page shows only 2 viable options for 2x48GB kits:

https://imgur.com/n0tyW4j 

https://rog.asus.com/motherboards/rog-maximus/rog-maximus-z790-hero-model/helpdesk_qvl_memory/

 
The kit you linked is F5-6800J3446F48GX2-RS5K but you bought the RGB F5-6800J3446F48GX2-TZ5RK it sounds like?

I notice that the spec sheet says it supports the F5-6800J3446G48GX2-TZ5RK, with the only difference being the F & G in the middle.  Is the F / G the typo you are referring to?  I bet you will have better luck just going with 2x32GB RGB sticks.

[matrosov1]

Thanks. Yes that was a typo.  32 should be arriving tomorrow we'll see how it goes.  Not looking forward to figuring out if it's MB or CPU if 32 does not work out.