MZ790E Q code 55 solved

[Hopper64]

Had to RMA the former MZ790E due to code 55 with GSkill 6400 memory all at default. Received the new MZ790E today. No problem. Boots without issue into the bios at default with the same memory kit. Testing memory at default currently.

Noticed that there’s a note to update to FW ….2020 BEFORE flashing bios 0703 on the Asus website:

“Before BIOS update, please download Intel ME update tool from ASUS support site, and update ME firmware to Version 16.1.25.2020 to ensure optimized system settings.”

I have not installed windows yet. Is there any mechanism to updating the FW outside windows?*

[Steve1983]

Hello Hopper.

Thanks for the hint but the slot has been used only for testing in the photo.
I tested both of the two 6400 16GB sticks in A2.
Later on I tested the other slots as well.
All combinations showed up code 55.

[Hopper64]

I would think the CPU or the memory is the issue if 2 different motherboards gave you the same problem. Unlikely both memory modules are defective. Wonder about the CPU itself. Wish you had an easy way to test it.

[Hopper64]

Didn't see a contact frame for the CPU. Looks like you are using the native ILM which eliminates another possible issue too.

[Steve1983]

Hello Hopper.
Correct, I don't have a contact frame, I don't know if I will retrofit it later.

I also think it is unlikely that both RAM sticks are broken. But I can't imagine that the CPU is defective either.

I will talk again with the dealer who sent me the parts, I had already sent the Z690 back (which was probably unnecessary).

Thanks for your advice.

[Hopper64]

Went through the same troubleshooting with Scone recently. He will chime in as well on this one. The motherboard was defective in my case.

[JohnAb]

Steve 1983 - If I understand, you haven't yet POSTed on the 690 or 790 boards?

I'm struggling to suggest a solution - but are your motherboard connectors properly inserted? Those big 24 pin connectors can take some real pressure to insert fully - be sure to support the motherboard from underneath if it needs a firmer push. Have a look at the edges of the connector, you'll see where the plastics faces should be touching and of course it should be all square and level. Just check everything - all the other connectors as well.

You could have a faulty CPU or RAM, which might be the obvious conclusion, (but not very likely to be the CPU itself, so look very carefully for dirt or damaged pins in the socket). Then as Hopper suggested try each DIMM, one at a time in socket A2. You might have just tried a faulty DIMM by bad luck so far. Again, look carefully for dirt or debris in the connector socket.

It sounds like you're not having much luck, but keep trying, take it slow and be logical... Do you have a friend or local shop that could try another CPU or different RAM for you?

[Steve1983]

JohnAb wrote:
Steve 1983 - If I understand, you haven't yet POSTed on the 690 or 790 boards?

I'm struggling to suggest a solution - but are your motherboard connectors properly inserted? Those big 24 pin connectors can take some real pressure to insert fully - be sure to support the motherboard from underneath if it needs a firmer push. Have a look at the edges of the connector, you'll see where the plastics faces should be touching and of course it should be all square and level. Just check everything - all the other connectors as well.

You could have a faulty CPU or RAM, which might be the obvious conclusion, (but not very likely to be the CPU itself, so look very carefully for dirt or damaged pins in the socket). Then as Hopper suggested try each DIMM, one at a time in socket A2. You might have just tried a faulty DIMM by bad luck so far. Again, look carefully for dirt or debris in the connector socket.

It sounds like you're not having much luck, but keep trying, take it slow and be logical... Do you have a friend or local shop that could try another CPU or different RAM for you?

Thanks for your input John.

Yes, exactly. The Z690-F passed the red CPU LED and then stopped at the yellow DRAM LED. No error tone over the speaker.

The Z790-E can display an error code and it stopped at code 55, so it stops at a similar stage as the Z690-F.

Thanks for the hint with the 24 pin connector. I checked again and I'm sure it's completely plugged in. I wanted to test my power supply from the "old" computer earlier, but unfortunately I only have one of the ATX 12V cables for the old power supply and have discarded the idea.

I also checked the CPU socket again with a flashlight, but couldn't find anything. No dust or a bent pin.
I also looked closely at the A2 RAM socket with a flashlight and couldn't find anything. After reassembling everything, I tested both RAM sticks individually in slot A2 again. Unfortunately, both sticks came up with code 55 again.

I'll call the local computer store tomorrow. But it's a small one and I don't know if they have high end stuff or are willing to help.

I will keep you updated, I hope the mystery is solved soon.

[Hopper64]

Let us know what you find. I am increasingly suspicious of the CPU itself.

[JohnAb]

Think I'm with Hopper. CPU failures aren't common, but they do happen. I hope your local store can help. That would be the quickest way - swap some bits and see what happens. I think that's going to be the only way forward. PSU also possible I guess, but probably less likely.

It seems strange, passes the CPU test and indicates RAM, although the memory controller is on the CPU itself I believe. RAM is easy to swap around, so if it was that I think you would have worked it out already. Hmmm. BIOS on defaults and XMP off? I guess so if you have recently flashed a new version. Problems like this are no fun at all, so I hope you make some progress soon.

[Steve1983]

Greetings, all.

No success yet but an update from my side.

I was able to give the parts (Z790-E, PSU, RAM and i5-13600K) to a computer store nearby. I got feedback today and picked up the parts again.

The board was tested with a different power supply, still code 55.
Another CPU was innstalled (an i5-13400), still code 55 and no access to BIOS.

A test with other DDR5 RAM could not be done, because the store had none. Another (third) board was also not tested.
The store nearby gave me the recommendation to exchange the DDR5 with the dealer, perhaps with another manufacturer or model I´m using now.

I will get on contact with the DDR5 dealer tomorrow.
Any recommendation what other DDR5 sticks to use with an Z790-E and an i5-13600K?