msi z270-a pro only works with two ram memories

Hi, the msi z270-a pro motherboard only works with two ram memory cards when I add one or two more and it won't boot anymore. Now I am using with two 8gb modules and I have two 4gb modules unused because of this problem. The cpu pins are fine, the cables are also well installed on the motherboard. So I don't know what the problem is that the pc only starts with two ram memories. I also tried the ram slots and they all work. I cleaned the slots with a fine brush and also cleaned the ram slots with an eraser but nothing, it does not work. Also when I changed the motherboard I did a clean Windows 10 installation. I attach a Windows image where you can see that it does not recognize neither the processor nor the installed ram and the second image is the most curious one which is something connected to the M.2 but I do not know what it is, that component connected to the m2 already came with the motherboard I bought.
Well I hope you can help me to solve this problem.
Thank you very much in advance.
Best regards.





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The blurry picture looks like an adapter that provides a PCI-E X4 slot from an M.2 socket. I have never seen anything like that before, and it's not obvious how you'd use it, physically. (Usually an X4 slot is used for a card in the back of the PC.)

One thing to try is using one pair of matching DIMMs at a time. Try the 4GB pair without having the 8GB pair in the PC. Does it boot then?

I regret that I can't reply in Spanish.

bobkn said:

The blurry picture looks like an adapter that provides a PCI-E X4 slot from an M.2 socket. I have never seen anything like that before, and it's not obvious how you'd use it, physically. (Usually an X4 slot is used for a card in the back of the PC.)

One thing to try is using one pair of matching DIMMs at a time. Try the 4GB pair without having the 8GB pair in the PC. Does it boot then?

I regret that I can't reply in Spanish.

Thank you very much for the answer. If the 4gb pair works and the 8gb pair works, a 4gb module will also work with an 8gb module.

As you have different memory sticks, did you read the MB manual to know where to install the 8G and the 4G sticks?
If the 4G doesn't have same specs of the 8G you may have a problem.
In witch memory slot you have the 8G sticks on?
What are the specs of the 8G and 4G sticks?

Megahertz said:

As you have different memory sticks, did you read the MB manual to know where to install the 8G and the 4G sticks?
If the 4G doesn't have same specs of the 8G you may have a problem.
In witch memory slot you have the 8G sticks on?
What are the specs of the 8G and 4G sticks?

I tried that ram configuration and it didn't work. Something that may be important that I don't clarify in the first message is that the bios leds when I put the four or three ram lights up the first led and then the second. The first one I think is the one with the cpu and the second one with the ram. Another thing I noticed is that when those lights are turned on, the fan in the middle of the gpu rotates for the second that the lights of the leds that mark errors last.

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BIOS doesn't have leds.
What are the specs of the 8G and 4G sticks?

Megahertz said:

BIOS doesn't have leds.
What are the specs of the 8G and 4G sticks?

the motherboard I meant, the leds on the motherboard.
4g: cmk4gx4m1a2400c14
4g: generic brand 4 GB DDR4-2400 DDR4 SDRAM
8gb:kvr21n5s8/8
8g:generic micron DDR4 SDRAM UDIMM 2400 MHz

Code:

CPU
		Intel Core i7 7700
			Cores	4
			Threads	8
			Name	Intel Core i7 7700
			Code Name	Kaby Lake
			Package	Socket 1151 LGA
			Technology	14nm
			Specification	Intel Core i7-7700 CPU @ 3.60GHz
			Family	6
			Extended Family	6
			Model	E
			Extended Model	9E
			Stepping	9
			Revision	B0
			Instructions	MMX, SSE, SSE2, SSE3, SSSE3, SSE4.1, SSE4.2, Intel 64, NX, VMX, AES, AVX, AVX2, FMA3
			Virtualization	Supported, Enabled
			Hyperthreading	Supported, Enabled
			Fan Speed	351 RPM
			Bus Speed	100.0 MHz
			Stock Core Speed	3600 MHz
			Stock Bus Speed	100 MHz
			Average Temperature	32 °C
				Caches
					L1 Data Cache Size	4 x 32 KBytes
					L1 Instructions Cache Size	4 x 32 KBytes
					L2 Unified Cache Size	4 x 256 KBytes
					L3 Unified Cache Size	8192 KBytes
				Cores
						Core 0
							Core Speed	3600.0 MHz
							Multiplier	x 36.0
							Bus Speed	100.0 MHz
							Temperature	31 °C
							Threads	APIC ID: 0, 1
						Core 1
							Core Speed	3600.0 MHz
							Multiplier	x 36.0
							Bus Speed	100.0 MHz
							Temperature	32 °C
							Threads	APIC ID: 2, 3
						Core 2
							Core Speed	3600.0 MHz
							Multiplier	x 36.0
							Bus Speed	100.0 MHz
							Temperature	32 °C
							Threads	APIC ID: 4, 5
						Core 3
							Core Speed	3600.0 MHz
							Multiplier	x 36.0
							Bus Speed	100.0 MHz
							Temperature	31 °C
							Threads	APIC ID: 6, 7
RAM
		Memory slots
			Total memory slots	4
			Used memory slots	2
			Free memory slots	2
		Memory
			Type	Unknown
			Size	16384 MBytes
			Channels #	Dual
			DRAM Frequency	1066.7 MHz
			CAS# Latency (CL)	15 clocks
			RAS# to CAS# Delay (tRCD)	15 clocks
			RAS# Precharge (tRP)	15 clocks
			Cycle Time (tRAS)	36 clocks
			Command Rate (CR)	2T
		Physical Memory
			Memory Usage	24 %
			Total Physical	16 GB
			Available Physical	12 GB
			Total Virtual	19 GB
			Available Virtual	13 GB
		SPD
			Number Of SPD Modules	2
				Slot #1
					Type	Unknown
					Size	8192 MBytes
					Manufacturer	Kingston
					Max Bandwidth	DDR4-2132 (1066 MHz)
					Part Number	9905622-058.A00G
					Serial Number	573610255
					Week/year	16 / 16
						Timing table
								JEDEC #1
									Frequency	666.7 MHz
									CAS# Latency	9,0
									RAS# To CAS#	9
									RAS# Precharge	9
									tRAS	22
									tRC	31
									Voltage	1,200 V
								JEDEC #2
									Frequency	814.8 MHz
									CAS# Latency	11,0
									RAS# To CAS#	11
									RAS# Precharge	11
									tRAS	27
									tRC	38
									Voltage	1,200 V
								JEDEC #3
									Frequency	888.9 MHz
									CAS# Latency	12,0
									RAS# To CAS#	12
									RAS# Precharge	12
									tRAS	30
									tRC	42
									Voltage	1,200 V
								JEDEC #4
									Frequency	963.0 MHz
									CAS# Latency	13,0
									RAS# To CAS#	13
									RAS# Precharge	13
									tRAS	32
									tRC	45
									Voltage	1,200 V
								JEDEC #5
									Frequency	1037.0 MHz
									CAS# Latency	14,0
									RAS# To CAS#	14
									RAS# Precharge	14
									tRAS	35
									tRC	49
									Voltage	1,200 V
								JEDEC #6
									Frequency	1066.1 MHz
									CAS# Latency	15,0
									RAS# To CAS#	15
									RAS# Precharge	15
									tRAS	36
									tRC	50
									Voltage	1,200 V
								JEDEC #7
									Frequency	1066.1 MHz
									CAS# Latency	16,0
									RAS# To CAS#	15
									RAS# Precharge	15
									tRAS	36
									tRC	50
									Voltage	1,200 V
				Slot #2
					Type	Unknown
					Size	8192 MBytes
					Manufacturer	Micron Technology
					Max Bandwidth	DDR4-2400 (1200 MHz)
					Part Number	8ATF1G64AZ-2G3H1
					Serial Number	1540686099
					Week/year	35 / 19
						Timing table
								JEDEC #1
									Frequency	727.3 MHz
									CAS# Latency	10,0
									RAS# To CAS#	10
									RAS# Precharge	10
									tRAS	24
									tRC	34
									Voltage	1,200 V
								JEDEC #2
									Frequency	800.0 MHz
									CAS# Latency	11,0
									RAS# To CAS#	11
									RAS# Precharge	11
									tRAS	26
									tRC	37
									Voltage	1,200 V
								JEDEC #3
									Frequency	872.7 MHz
									CAS# Latency	12,0
									RAS# To CAS#	12
									RAS# Precharge	12
									tRAS	28
									tRC	40
									Voltage	1,200 V
								JEDEC #4
									Frequency	945.5 MHz
									CAS# Latency	13,0
									RAS# To CAS#	13
									RAS# Precharge	13
									tRAS	31
									tRC	44
									Voltage	1,200 V
								JEDEC #5
									Frequency	1018.2 MHz
									CAS# Latency	14,0
									RAS# To CAS#	14
									RAS# Precharge	14
									tRAS	33
									tRC	47
									Voltage	1,200 V
								JEDEC #6
									Frequency	1090.9 MHz
									CAS# Latency	15,0
									RAS# To CAS#	15
									RAS# Precharge	15
									tRAS	35
									tRC	50
									Voltage	1,200 V
								JEDEC #7
									Frequency	1163.6 MHz
									CAS# Latency	16,0
									RAS# To CAS#	16
									RAS# Precharge	16
									tRAS	38
									tRC	54
									Voltage	1,200 V
								JEDEC #8
									Frequency	1200.5 MHz
									CAS# Latency	17,0
									RAS# To CAS#	17
									RAS# Precharge	17
									tRAS	39
									tRC	55
									Voltage	1,200 V
								JEDEC #9
									Frequency	1200.5 MHz
									CAS# Latency	18,0
									RAS# To CAS#	17
									RAS# Precharge	17
									tRAS	39
									tRC	55
									Voltage	1,200 V
								JEDEC #10
									Frequency	1200.5 MHz
									CAS# Latency	19,0
									RAS# To CAS#	17
									RAS# Precharge	17
									tRAS	39
									tRC	55
									Voltage	1,200 V
								JEDEC #11
									Frequency	1200.5 MHz
									CAS# Latency	20,0
									RAS# To CAS#	17
									RAS# Precharge	17
									tRAS	39
									tRC	55
									Voltage	1,200 V
								JEDEC #12
									Frequency	1200.5 MHz
									CAS# Latency	21,0
									RAS# To CAS#	17
									RAS# Precharge	17
									tRAS	39
									tRC	55
									Voltage	1,200 V
Motherboard
	Manufacturer	MSI
	Model	Z270-A PRO (MS-7A71)
	Version	1.0
	Chipset Vendor	Intel
	Chipset Model	Kaby Lake
	Chipset Revision	05
	Southbridge Vendor	Intel
	Southbridge Model	Z270
	Southbridge Revision	00
	System Temperature	33 °C
		BIOS
			Brand	American Megatrends Inc.
			Version	1.60
			Date	29/6/2018
		Voltage
			CPU CORE	0.744 V
			MEMORY CONTROLLER	1.008 V
			AVCC	3.408 V
			3VCC	3.344 V
			VIN4	1.024 V
			VIN5	0.144 V
			VIN6	1.120 V
			VIN7	1.064 V
			VIN8	0.768 V
			VIN9	0.600 V
			VIN10	1.024 V
			VIN11	1.008 V
			VIN12	1.120 V
			VIN13	1.000 V
			VIN14	0.000 V
		PCI Data
				Slot PCI-E
					Slot Type	PCI-E
					Slot Usage	In Use
					Data lanes	x16
					Slot Designation	J6B2
					Characteristics	3.3V, Shared, PME
					Slot Number	0
				Slot PCI-E
					Slot Type	PCI-E
					Slot Usage	In Use
					Data lanes	x1
					Slot Designation	J6B1
					Characteristics	3.3V, Shared, PME
					Slot Number	1
				Slot PCI-E
					Slot Type	PCI-E
					Slot Usage	In Use
					Data lanes	x1
					Slot Designation	J6D1
					Characteristics	3.3V, Shared, PME
					Slot Number	2
				Slot PCI-E
					Slot Type	PCI-E
					Slot Usage	In Use
					Data lanes	x1
					Slot Designation	J7B1
					Characteristics	3.3V, Shared, PME
					Slot Number	3
				Slot PCI-E
					Slot Type	PCI-E
					Slot Usage	In Use
					Data lanes	x1
					Slot Designation	J8B4
					Characteristics	3.3V, Shared, PME
					Slot Number	4
				Slot PCI-E
					Slot Type	PCI-E
					Slot Usage	In Use
					Data lanes	x1
					Slot Designation	J8D1
					Characteristics	3.3V, Shared, PME
					Slot Number	5
				Slot PCI
					Slot Type	PCI
					Slot Usage	In Use
					Bus Width	32 bit
					Slot Designation	J8B3
					Characteristics	3.3V, Shared, PME
					Slot Number	6

Even the two 8G are different.
Slot 1 8G is Kingston - DDR4-2132 16-15-15-36
Slot 2 8G is Micron - DDR4-2400 21-17-17-39

If you don't want memory issues, don't mix memory types