[Edit]: Arrgh it turns out I nicked a character from another line while setting the pciex1_gen=3
param and after fixing that things are back to normal… Whoops! Anyways, hope your case turned out equally successful if less embarrassing! 
Hi @Ray71 where did your story take you, were you able to get a stable system after all?
I believe I’m currently in exactly the same situation, my setup[1] worked fine for a few days and then all of a sudden it seems like there’s no communication with the hat at all: no blue LEDs for disks, disks are no longer visible, and afaict from lspci
the hat itself is not visible.
I get identical output from $ dmesg | grep -i pcie
:
[ 0.000000] Kernel command line: reboot=w coherent_pool=1M 8250.nr_uarts=1 pci=pcie_bus_safe cgroup_disable=memory numa_policy=interleave smsc95xx.macaddr=2C:CF:67:AB:BC:13 vc_mem.mem_base=0x3fc00000 vc_mem.mem_size=0x40000000 console=ttyAMA10,115200 console=tty1 root=PARTUUID=da20a566-02 rootfstype=ext4 fsck.repair=yes rootwait cfg80211.ieee80211_regdom=PL
[ 1.800620] brcm-pcie 1000120000.pcie: host bridge /axi/pcie@120000 ranges:
[ 1.807614] brcm-pcie 1000120000.pcie: No bus range found for /axi/pcie@120000, using [bus 00-ff]
[ 1.816703] brcm-pcie 1000120000.pcie: MEM 0x1f00000000..0x1ffffffffb -> 0x0000000000
[ 1.825009] brcm-pcie 1000120000.pcie: MEM 0x1c00000000..0x1effffffff -> 0x0400000000
[ 1.833311] brcm-pcie 1000120000.pcie: IB MEM 0x1f00000000..0x1f003fffff -> 0x0000000000
[ 1.841617] brcm-pcie 1000120000.pcie: IB MEM 0x0000000000..0x0fffffffff -> 0x1000000000
[ 1.851074] brcm-pcie 1000120000.pcie: Forcing gen 2
[ 1.856255] brcm-pcie 1000120000.pcie: PCI host bridge to bus 0000:00
[ 2.017254] brcm-pcie 1000120000.pcie: link up, 5.0 GT/s PCIe x4 (!SSC)
[ 2.133746] pcieport 0000:00:00.0: enabling device (0000 -> 0002)
[ 2.139892] pcieport 0000:00:00.0: PME: Signaling with IRQ 38
[ 2.145692] pcieport 0000:00:00.0: AER: enabled with IRQ 38
I initially thought the change happened when I tried to enable dtparam=pciex1_gen=3
, but removing this parameter or setting it to 2 has not had any effect.
My testing options are limited as this is my first foray into RPi land.
Did you figure out any way to get this to work in a stable way? Did you get any help from Arace Tech?
[1] Raspberry Pi + Penta hat + power over 12V 5A barrel + 4x 2.5" SSDs in the SATA slots (no eSATA). I was usuing eSATA with a 3.5" HDD for initial testing.