Motherboard code 55

[Iamazn]

I just finished putting everything together and when I turned it on, the LED display on the mobo reads 55. What's wrong?

[AUGieDogie]

On my M5F the manual says code 55 is "no memory installed"

[SoF]

try booting with single channel first, then apply RAM settings, then reboot, check, shut-down and insert the second one.

usually happens with some crappy RAM or if you change from certain IC to IC (e.g. Hynix CFR --> PSC = "55" always...)

Something with the sub-timings on mem-reset imo...

[Iamazn]

Reseating the RAM fixed it.

[SrDidE]

You can search the 55 code with this tool: http://www.asusqcodes.com/index.php?inputCode=55

for code 55 I found:
The Memory could not be detected. Please re-install the memory and CPU. If the problem still exists, please install only one memory module or try using other memory modules.

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[max0x7ba]

Iamazn wrote:
I just finished putting everything together and when I turned it on, the LED display on the mobo reads 55. What's wrong?

I had the same error on ASUS Maximus IX Hero with i7-7700k: Q-Code 55 with my 4x8GB DIMM of G.Skill Trident Z 4000MHz. I fixed it by following advice given in https://community.hwbot.org/topic/147255-guide-skylake-memory-timings-on-asus-motherboards/

In particular, I switched to XMP profile and set TRDWR_sg, TRDWR_dg, TRDWR_dr and TRDWR_dd to 18 (my memory has 18-19-19-39 timings), and TWRWR_DD to 8. That fixed it.

It seems to be ASUS-specific bug that it does not set TRDWR_sg, TRDWR_dg, TRDWR_dr and TRDWR_dd to CL/CAS-latency value automatically.