Yes, you can install a 1x PCIe card into a 16x or 4x PCIe slot

Yes, you can install a 1x PCIe card into a 16x or 4x PCIe slot 16x pcie slot Yes, a x1 card should work in a x16 slot It's good that you've got it to work in a x1 slot What else have you tried it in besides the x16 slot slot saw Identifying Different Types of PCIe Slots

slot saw PCIe x16: This is the largest PCIe slot with 16 data lanes PCIe x16 slots are associated with graphics cards and provide the highest bandwidth

yale slot Solution · Re-seat the PCIe card in the PCIe slot · Try the PCIe card in another PCIe slot in the same computer · Try the card in another PCIe cards can always operate in PCIe slots with the same or more lanes than the card For example, an x8 card can operate in a slot with x8, x16, or x32 lanes