F5F Stay Refreshed Hardware Desktop Discussing PCIe lanes, power supply options, and a peculiar PCIe to mini PCIe adapter card.

Discussing PCIe lanes, power supply options, and a peculiar PCIe to mini PCIe adapter card.

Discussing PCIe lanes, power supply options, and a peculiar PCIe to mini PCIe adapter card.

H
Hidekih
Posting Freak
849
10-06-2021, 12:47 AM
#1
So where should we begin... I’m currently assembling an x86 router from scratch. I’ve selected a H310 motherboard with an integrated Intel RJ45 port and now aim to integrate 4G/LTE features. I purchased a 4G modem, but it’s available only in M.2 or miniPCIe forms, so I opted for the latter. I needed a method to link it to the board, ideally placed in the rear PCIe slot for convenient antenna access. That’s when I acquired this adapter: Amazon.com: Mini PCI-E PCI Express to PCI-E 1x Adapter with SIM Card Slot. The back features a SIM slot since otherwise connecting to the 4G network would be impossible. This marked the start of my journey. Naturally, I inserted the modem, adjusted the card’s voltage setting (switch position 2-3), placed a SIM card inside, and powered it up in my Z370 PC (ASUS Maximus X Hero WiFi AC). Windows didn’t recognize it at all—Device Manager didn’t list it, and the card vanished entirely. I explored multiple PCIe slots, even an outdated 990FX motherboard, but nothing worked. I ventured into BIOS settings for the Z370, discovering an option to disable the PCIe_x1 slot so the x4 lanes could be routed through the second M.2 port. Driven by urgency, I disabled it, and suddenly Windows displayed the modem in Device Manager. After some adjustments under Windows 11, a stable 4G connection appeared. Then I powered down the system to attempt reinstallation on the H310 board, where the card was meant to fit. This phase became increasingly puzzling. Once shut off, the Z370 rebooted within seconds and reappeared in Device Manager. After restarting and entering BIOS, I managed to assign the lanes correctly, finally seeing the modem. Later, I tried removing the adapter from the H310 and placed it back on the desktop, where I’d previously fixed it by altering BIOS settings. This time, after a power loss (removing the PSU power cord), the card was detected again—only after navigating through BIOS settings to assign lanes to the M.2 slot. It worked once I reset the BIOS and set it to X2 for proper detection. This suggests the motherboard’s POST process might be sensing something in the PCIe lane but failing to supply sufficient power. I suspect the issue lies in power delivery rather than the adapter itself. Even though the modem lights up, its LEDs remain active, indicating it receives power through the lanes. It’s possible the system scans for USB devices before powering the PCIe slot, and without power during POST, it goes unnoticed. I also tested the adapter with an older 54Mbps WiFi mini PCIe card from a 2008 laptop—this one functioned perfectly out of the box. A newer WiFi 6 mini PCIe version failed to appear at all. The only clue points to power delivery problems.
H
Hidekih
10-06-2021, 12:47 AM #1

So where should we begin... I’m currently assembling an x86 router from scratch. I’ve selected a H310 motherboard with an integrated Intel RJ45 port and now aim to integrate 4G/LTE features. I purchased a 4G modem, but it’s available only in M.2 or miniPCIe forms, so I opted for the latter. I needed a method to link it to the board, ideally placed in the rear PCIe slot for convenient antenna access. That’s when I acquired this adapter: Amazon.com: Mini PCI-E PCI Express to PCI-E 1x Adapter with SIM Card Slot. The back features a SIM slot since otherwise connecting to the 4G network would be impossible. This marked the start of my journey. Naturally, I inserted the modem, adjusted the card’s voltage setting (switch position 2-3), placed a SIM card inside, and powered it up in my Z370 PC (ASUS Maximus X Hero WiFi AC). Windows didn’t recognize it at all—Device Manager didn’t list it, and the card vanished entirely. I explored multiple PCIe slots, even an outdated 990FX motherboard, but nothing worked. I ventured into BIOS settings for the Z370, discovering an option to disable the PCIe_x1 slot so the x4 lanes could be routed through the second M.2 port. Driven by urgency, I disabled it, and suddenly Windows displayed the modem in Device Manager. After some adjustments under Windows 11, a stable 4G connection appeared. Then I powered down the system to attempt reinstallation on the H310 board, where the card was meant to fit. This phase became increasingly puzzling. Once shut off, the Z370 rebooted within seconds and reappeared in Device Manager. After restarting and entering BIOS, I managed to assign the lanes correctly, finally seeing the modem. Later, I tried removing the adapter from the H310 and placed it back on the desktop, where I’d previously fixed it by altering BIOS settings. This time, after a power loss (removing the PSU power cord), the card was detected again—only after navigating through BIOS settings to assign lanes to the M.2 slot. It worked once I reset the BIOS and set it to X2 for proper detection. This suggests the motherboard’s POST process might be sensing something in the PCIe lane but failing to supply sufficient power. I suspect the issue lies in power delivery rather than the adapter itself. Even though the modem lights up, its LEDs remain active, indicating it receives power through the lanes. It’s possible the system scans for USB devices before powering the PCIe slot, and without power during POST, it goes unnoticed. I also tested the adapter with an older 54Mbps WiFi mini PCIe card from a 2008 laptop—this one functioned perfectly out of the box. A newer WiFi 6 mini PCIe version failed to appear at all. The only clue points to power delivery problems.